Risk assessment: What is the plausible ‘worst scenario’ for climate change?

by Judith Curry

We know that climate change is a problem – but how big a problem is it? We have to answer this question before we can make a good decision about how much effort to put into dealing with it.

Climate Seer James Hansen Issues His Direst Forecast Yet.  Jim Hansen has submitted a new paper for publication (can’t find a copy yet).  But it is already making a splash in the media.  Excerpts:

James Hansen is now warning that humanity could confront “sea level rise of several meters” before the end of the century unless greenhouse gas emissions are slashed much faster than currently contemplated.

This roughly ten feet of sea level rise—well beyond previous estimates—would render coastal cities such as New York, London and Shanghai uninhabitable. “Parts of [our coastal cities] would still be sticking above the water,” Hansen says, “but you couldn’t live there.”

Is Hansen’s forecast plausible? Even Mann is skeptical (see his quote in WaPo article).  What does ‘plausible’ mean?  What is the plausible worst case scenario for human caused climate change?

Climate Change: A Risk Assessment

I haven’t found climate change risk assessments to be very satisfactory, for a range of reasons.  There is a new report out, entitled Climate Change: A Risk Assessment.  IMO  this is far and away the best risk assessment for AGW that I have seen.   That said, it is far from perfect, for reasons described towards the end of the post (largely associated with how much warming we can expect, which is obviously the key issue).  But  IMO it has appropriately framed the climate risk assessment problem, and its authors (for the most part) don’t seem to have any obvious agenda beyond . . . risk assessment.

From the summary on the Cambridge web site:

This report argues that the risks of climate change should be assessed in the same way as risks to national security, financial stability, or public health. That means we should concentrate especially on understanding what is the worst that could happen, and how likely that might be.

The report presents a climate change risk assessment that aims to be holistic, and to be useful to anyone who is interested in understanding the overall scale of the problem. It considers:

  • What we are doing to the climate: the future trajectory of global greenhouse gas emissions;
  • How the climate may change, and what that could do to us – the ‘direct risks’ arising from the climate’s response to emissions;
  • What, in the context of a changing climate, we might do to each other – the ‘systemic risks’ arising from the interaction of climate change with systems of trade, governance and security;
  • How to value the risks; and
  • How to reduce the risks – the elements of a proportionate response.

Some excerpts of relevance to formulating the plausible worst case scenario:

In assessing the risk of climate change, the immediate questions for any country anywhere in the world are: How serious is the threat? How urgent is it? How should we prioritise our response, when we have so many other pressing, national objectives – from encouraging economic recovery to protecting our people around the world?

A risk assessment asks the questions: ‘What might happen?’, ‘How bad would that be?’ and ‘How likely is that?’ The answers to these questions can inform decisions about how to respond.

Climate change fits the definition of a risk because it is likely to affect human interests in a negative way, and because many of its consequences are uncertain. We know that adding energy to the Earth system will warm it up, raising temperatures, melting ice, and raising sea levels. But we do not know how fast or how far the climate will warm, and we cannot predict accurately the multitude of associated changes that will take place. The answer to the question ‘how bad could it be?’ is far from obvious.

Consider the full range of probabilities. The biggest risks could lie anywhere in the probability distribution . . . particular importance of not ignoring low probability, high impact risks. It is a matter of judgment how low a probability is worth considering. When a probability cannot be meaningfully quantified, it is usual to consider a ‘plausible worst case’. Again, the question of what is a relevant threshold of ‘plausibility’ is a matter of judgment.

What is the probability of following a high emissions pathway? Based on an analysis of current policies and plans for major countries and regions, it is very likely that the world will continue to follow a medium to high emissions pathway for the next few decades. If goals for reducing emissions in the EU and the U.S. and stabilizing emissions in China are achieved, then the highest emissions scenarios are less likely to occur, especially if India is able to displace a part of its anticipated construction of new coal-fired power plants with renewable energy capacity. But this will only keep emissions on a moderate trajectory, still far in excess of what is required to limit the impacts of climate change below a harmful level.

How likely are we to exceed the temperature thresholds we’ve identified?  For any emissions pathway, a wide range of global temperature increases is possible. On all but the lowest emissions pathways, a rise of more than 2°C is likely in the latter half of this century. On a medium-high emissions pathway (RCP61), a rise of more than 4°C appears to be as likely as not by 2150. On the highest emissions pathway (RCP8.5), a rise of 7°C is a very low probability at the end of this century, but appears to become more likely than not during the course of the 22nd century. A rise of more than 10°C over the next few centuries cannot be ruled out.

Basically, they are using the IPCC AR5 here.  The ensemble of climate model simulations for different emissions pathways should be regarded as individual scenarios of future climate change, and probability cannot be meaningfully quantified; see these previous CE posts:

‘Plausible’ versus ‘possible’

I have argued previously that the probabilities and even the likelihoods determined from climate model simulations are misleading.  Which brings us back to ‘What is the plausible worst case scenario?’

‘Plausible’ seems a plausibly useful word, but one that is ambiguous.  A dictionary definition of plausible: falls within the limits of what might conceivably happen. How is ‘plausible’ different from ‘possible’?

Financial risk management has long grappled with these issues.  The ASU-Oxford Plausibility Project has an interesting and relevant essay: How plausible is plausibility as a scenario effectiveness criterion?  The essay doesn’t come up with a definitive solution, but addresses the challenges of navigating between the too plausible and too implausible extremes.

I propose the following distinction between ‘possible’ and ‘plausible’:

Plausible:  a future scenario that cannot be rejected or falsified based on background knowledge.  Scenario falsification was discussed in a previous CE thread.  Update:  The idea of plausibility further rests on an assessment of uncertainties in the background knowledge.

Possible:  a future scenario that is not consistent with background knowledge, but given the uncertainties in our knowledge can be regarded as possible.

Hence a plausible scenario is possible, but a possible scenario may not be plausible.  As an example, I regard Jim Hansen’s sea level rise scenario as possible but not plausible (with the caveat that I haven’t read the paper and with the assumption that the paper presents no new observational evidence).  Most alarming scenarios fall in this category of possible but not plausible.

Policy responses generally focus on the plausible scenarios, while continuing to assess the plausible worst case scenario and the plausibility of the far-out possible scenarios.  There is a practical and philosophical issue of plausible versus possible ‘ruin’ scenarios (see previous CE post).

Plausible worst case scenario

I regard there to be two main elements to formulating the plausible worst case scenario for human-caused climate change:

  • The highest plausible representative concentration pathway (see previous CE post)
  • The highest plausible equilibrium climate sensitivity (see previous CE post)

The highest representative concentration pathway formulated by the IPCC is RCP8.5.  In a previous post Coal and the IPCC, Dave Rutledge argued that RCP8.5 was not a plausible scenario.  I just spotted a post by Blair King entitled On RCP8.5 and the business as usual scenario, which also challenges the plausibility of RCP8.5.  I suspect there are other challenges to the plausibility of this scenario, but I haven’t really looked.

With regards to climate sensitivity, see my previous post Climate sensitivity: lopping off the fat tail. Excerpt:

Gregor Betz defines modal falsification as follows [BetzModalFalsification]:

Modal falsification: It is scientifically shown that a certain statement about the future is possibly true as long as it is not shown that this statement is incompatible with our relevant background knowledge, i.e. as long as the possibility statement is not falsified.

Nic Lewis’ research arguably falsifies the high values of climate sensitivity determined from instrumental data, owing to problems with the statistical methodology and the forcing data. IMO, Nic’s methodology for determining climate sensitivity from observations and energy balance model represents the best current method.

With regards to climate model determinations, see this paper: The upper end of climate model temperature projections is inconsistent with past warming, by Peter Stott, Peter Good, Gareth Jones, Nathan Gillett, Ed Hawkins, published in Environmental Research Letters (open access) [link]. This paper does not directly address the issue of climate sensitivity. It is obvious from comparing climate model simulations with observations that most climate models are running too hot for the early years of the 21st century.

It is becoming increasingly difficult to defend values of ECS that exceed 3.5C.  The threshold warming values identified in the Climate Risk Assessment Report of 4C and 7C by 2150 are possible but they may not be plausible.  Since this warming is inferred by climate model simulations, falsification of these scenarios could be accomplished by comparing modeled and observed warming for the period since 1950, and assessing whether the equilibrium climate sensitivity for that model is too high (with a value of aerosol indirect effect that is far too high).

The plausible worst case scenario is arguably where we should focus our efforts (both science and policy).  Working to falsify high values of RCP and sensitivity based on the background knowledge that we do have, should be a high priority.

JC conclusions

I think the new Climate Change Risk Assessment document is an important step forward in framing how we should approach climate change risk assessment.  The appropriate focus is the plausible worst case scenario, which has not been a focus of the IPCC or climate establishment.  Instead they have focused on a mean, a likely range, or an alarming possibility.

I have proposed scenario falsification as a way to proceed, in terms of identifying plausible versus possible scenarios.  I hope that risk assessors, philosophers and climate scientists can work together and shift their focus to scientifically robust and policy useful strategies for assessing the plausible worst case scenario for human caused global warming.

 

514 responses to “Risk assessment: What is the plausible ‘worst scenario’ for climate change?

  1. Return of the Little Ice Age

    • Return of a big Ice Age
      Scott

      • David Springer

        What about asking how good it can get?

        There are great benefits to a warmer planet with an atmosphere richer in CO2.

        Sea level rise is 3mm/year, not accelerating and not a big problem if it stays that way. That’s one foot per century. Hansen’s unsupportable claim is that this rate will somehow grow to 10x “real soon now”.

        That non-problem needs to be adequately weighed against a planet that is measurably getting greener as CO2 increases and a human condition that is vastly improved through global industry, transportation, and agriculture made possible by inexpensive fossil fuel energy.

        http://earthobservatory.nasa.gov/Features/GlobalGarden/

      • David Springer

        What about asking how good it can get?

        There are great benefits to a warmer planet with an atmosphere richer in CO2.

        Sea level rise is 3mm per year, not accelerating and not a big problem if it stays that way. That’s one foot per century. Hansen’s wild claim is that this rate will somehow grow to ten times the current rate “real soon now”.

        That non-problem needs to be adequately weighed against a planet that is measurably getting greener as CO2 increases and a human condition that is vastly improved through global industry, transportation, and agriculture made possible by inexpensive fossil fuel energy.

        http://earthobservatory.nasa.gov/Features/GlobalGarden/

    • Turning into Venus.

      • Canman,

        Not even possible.

      • Venus: 965,000 ppm CO2, no magnetic field, cyclic catastrophic volcanic resurfacing events…

      • Not even a remote possibility of that

      • With the Sun expanding into a red giant over astrological time, the Earth eventually has to turn into Venus.

      • Getting cooked by an expanding sun ain’t the same thang canman. Uncannily silly…

      • Venus doesn’t rotate (enough to matter). Earth does.

      • I remember a thread at WUWT where someone said Earth escaped Venus’s fate by having excess CO2 absorbed by shell creatures and turned into carbonate.

      • @Canman: I remember a thread at WUWT where someone said Earth escaped Venus’s fate by having excess CO2 absorbed by shell creatures and turned into carbonate.

        (Boldface mine, to indicate issues.)

        CO2’s uptake at the surface is primarily via photosynthesis (which turns CO2 into carbohydrates), weathering of rocks (which turns CO2 into limestone etc.) , and absorption by the ocean (which turns CO2 into carbonic acid).

        Crustaceans (“shell creatures”) benefit only indirectly, and that via only the second of the above, wherein the limestone very slowly makes its way to the coast and thence into the ocean as insoluble calcium carbonate. In that form it is beneficial to crustaceans.

        Unfortunately the third of the above compromises that benefit by reacting with insoluble calcium carbonate to turn it into soluble calcium bicarbonate, which is not only useless to crustaceans but even dissolves the shell they’d built from the calcium carbonate.

        It’s a delicate balance.

      • You mean we would lose our arms?

      • Are you referring to Caitlin Jenner (aka Bruce)

      • More importantly, Venus does not have a large satellite moon.

      • Even if Earth didn’t have a moon it would still have tides thanks to the Sun. They would still be on a 12-hour clock, but would only be half as strong and there would be no neap-tide king-tide variation.

        More importantly than that Venus doesn’t have a moon is that its day is 2802 hours, vs. 24 hours for Earth. So the tides induced by the Sun are on a cycle that is nearly 120 times slower than on Earth.

      • So the tides induced by the Sun are on a cycle that is nearly 120 times slower than on Earth.

        Tides are a nit. Try geostrophic effect.

      • Coriolis effect (real, measurable), geostrophic flow (theoretical, ideal, namely the fluid flow in atmosphere or ocean that would in principle be needed to achieve geostrophic balance, the condition in which the Coriolis effect exactly balances the pressure gradient).

        Geostrophic balance is important on Earth in both the ocean and the atmosphere. Venus however has no ocean, leaving only the atmosphere. But Venus rotates 244 times slower than Earth (so her equator moves at only 6.52 kph or 4.05 mph), despite having a day that is only 117 times longer than Earth’s (so high noon travels at 8.43 mph).

        So if that were all there was to it there would be no significant Coriolis effect in the atmosphere and therefore no meaningful geostrophic wind (way down in the noise).

        Except that Venus’s atmosphere has lately been blowing at up to 400 kph:

        http://www.esa.int/var/esa/storage/images/esa_multimedia/images/2013/06/increasing_wind_speeds_on_venus/12895012-1-eng-GB/Increasing_wind_speeds_on_Venus_node_full_image_2.jpg

        (White curve plotted by tracking 45,000 features manually, black curve digitally based on 350,000 features.)

        This is 60x faster than the equator moves. But Earth’s equator moves at 1670 kph, 4x faster again. Hence the Coriolis effect in Venus’s atmosphere is only a quarter that of Earth’s.

        Ordinary wind blows normally to the isobars (lines of equal pressure), namely from high pressure to low. Geostrophic wind is the additional movement parallel to the isobars, i.e. the sideways deflection, required to balance the Coriolis force resulting from ordinary wind moving in a rotating frame. Since wind on Venus is much faster than on Earth, at least below the jet stream, the geostrophic wind on Venus would be greater on Earth in that proportion, except that the 4x slower rotation of Venus’s atmosphere reduces Venus’s geostrophic wind by that amount.

        In terms of angles, geostrophic flow changes the direction of wind on Venus by only a quarter of the angle changed on Earth. Six years ago it was only 3/16 (see figure).

        I mention all this only because it’s interesting (to me anyway), not because it has any obvious bearing on why most of Venus’s carbon is airborne, which (more or less) was the original question.

      • Ordinary wind blows normally to the isobars (lines of equal pressure), namely from high pressure to low.

        True, but mostly it doesn’t, on Earth. Except at boundary layers, and close to the equator, all wind is effectively geostrophic.

        This means that, except near the equator, very large concentrations of high or low pressure can maintain themselves for a very long time, relative to the effects of radiative cooling (and warming).

        The fact that the Earth has this geostrophic effect everywhere except near the equator means that Earth won’t “turn into another Venus”.

        Not to say that some sort of “runaway greenhouse effect” can be totally ruled out, and it might even have a few parallels to Venus. But the differences are huge, and Venus can’t be used as a valid analogy.

        Of course, there’s the Moon also. It’s slowing the Earth down, meaning it probably (but not certainly) was spinning faster in the past. It seems unlikely that Venus’ original rotation was damped by Solar tides, given that the much stronger Lunar tides haven’t damped the Earth’s rotation.

        But it’s not impossible that Venus and Mercury were originally a “twin planet” like the Earth/Moon system. And in that case, it’s quite possible that Venus lost an original rotation similar to Earth’s a long time ago.

        But the Venus/Mercury “twin planet” thing is entirely speculative. Even if it happened, we have no reason to suppose that Venus had achieved its current atmospheric arrangement while it still had Earth-like rotation.

      • @AK: True, but mostly it doesn’t, on Earth. Except at boundary layers, and close to the equator, all wind is effectively geostrophic.

        Well, that makes me very wrong then. I’ll have read John Nielsen-Gammon’s notes in some detail before I understand this.

        What particularly puzzles me is the case when the pressure isobars run north-south. If the geostrophic wind always follows those contours then shouldn’t the Coriolis effect deflect the geostrophic wind in an east-west direction? Something’s fishy about that.

        This means that, except near the equator, very large concentrations of high or low pressure can maintain themselves for a very long time, relative to the effects of radiative cooling (and warming). The fact that the Earth has this geostrophic effect everywhere except near the equator means that Earth won’t “turn into another Venus”.

        I have no idea how this is supposed to work. Could you provide a little more detail?

        It seems unlikely that Venus’ original rotation was damped by Solar tides, given that the much stronger Lunar tides haven’t damped the Earth’s rotation.

        I disagree. While it’s true that the Moon is 282 times closer to Earth than the Sun is to Venus, the cube of that (the quantity relevant to tides) is only 22 million, whereas the Sun is 27 million times heavier than the Moon. On the other hand Venus’s radius is about 5% less than Earth’s. The upshot is that the solar tides at the surface of Venus are stronger than the lunar tides at the surface of Earth by a factor of 0.95*27/22 = 1.15, i.e. about 15% stronger.

        (To compare solar to lunar tides at Earth’s surface, drop the 0.95 and change 282 to 389, whose cube is 59 million. Earth’s solar tides are therefore 27/59 = 46% of the strength of the lunar tides, as is well known. 45.93% if done to more precision, but typically approximated in the literature as “about a half”. If it were much less there’d be much less difference between king and neap tides.)

        There is the further fact that Venus’s higher surface temperature implies a softer crust, which will therefore flex more than Earth’s crust under the influence of the respective tides. This will transfer more of Venus’s rotational energy to heating the crust, thereby slowing Venus faster than the combined action of lunar and solar tides on Earth’s watery oceans.

        Hence the sequence could be the opposite of yours. Venus may have put progressively more of her carbon into her atmosphere as she heated up, thereby softening her crust, thus causing her to slow down until one side was permanently facing the Sun, with her (counterclockwise) sidereal rotation period matching her sidereal orbit period of 224.7 Earth days. A passing asteroid may have subsequently hit her at a point that decreased her counterclockwise spin ever so slightly. This would create a distinction between morning and afternoon in the clouds at around 100 km above the surface, with the hotter afternoon air rising, then heading east at say 110 or 120 km, then down to the cooler morning side, creating a westward breeze at 100 km. This breeze would gradually spin up the rest of the atmosphere clockwise about an axis normal to the ecliptic until it reached a sidereal period of just a few days. This huge wind would in turn slow down Venus’s counterclockwise rotation and eventually reverse it to its current clockwise sidereal rotation period of 243 Earth days.

        But it’s not impossible that Venus and Mercury were originally a “twin planet” like the Earth/Moon system. And in that case, it’s quite possible that Venus lost an original rotation similar to Earth’s a long time ago.

        As I calculated above, the Sun can just as well play the role you’re presumably assigning to Mercury here.

        But the Venus/Mercury “twin planet” thing is entirely speculative. Even if it happened, we have no reason to suppose that Venus had achieved its current atmospheric arrangement while it still had Earth-like rotation.

        Well, I don’t understand how either of our respective theories accounts for Venus’s huge CO2 atmosphere. You’ll have to explain how geostrophic wind is what is preventing Earth from suffering Venus’s fate.

        However your theory does not explain how Venus came to be spinning so slowly without making Mercury a moon of Venus, nor does it explain why she’s spin down (clockwise) when all the other planets are spin up, whereas mine does both.

        I’ll take your point about the geostrophic effect however, at least until I understand how it works. I find it very puzzling.

      • If the geostrophic wind always follows those contours then shouldn’t the Coriolis effect deflect the geostrophic wind in an east-west direction? Something’s fishy about that.

        Yes, the Coriolis effect deflects tries to deflect the wind in an east-west direction with a force that exactly balances the pressure gradient. If you assume a pressure gradient without a geostrophic wind, wind will start to blow from high pressure to low, get deflected by the Coriolis effect, and continue to bend until it reaches equilibrium as the Geostrophic wind.

        I have no idea how this is supposed to work. Could you provide a little more detail?

        Consider a tall mass of cool air surrounded by warmer. The adiabatic pressure gradient is greater for the cool air, so if, say, the pressure is identical at the surface, it will be much lower at 10Km. Thus there will be a strong pressure gradient from the surrounding mass of warm air towards the upper part of the mass of cool air.

        Absent the geostrophic/Coriolis effect, that air would flow down the pressure gradient, the cool air would expand at the bottom and spread out under the warm air.

        But because the geostrophic wind balances the pressure gradient, the top of the mass of cool air can remain in place. Of course, at the surface, friction slows the geostrophic wind, which reduces its ability to counter the pressure gradient.

        The resulting average velocity of the resulting wind is zero at the actual surface, with a direction deflected 45°, midway between the pressure gradient and direction of geostrophic flow. From the surface, it rises and spirals towards the direction of flow, until at a height of something like a kilometer, it’s parallel to the flow. The layer at the boundary where this occurs is called the Ekman layer.

        Somewhat similar situations hold at the top of layer of general turbulence (troposphere on Earth), tho with many differences. For instance, poleward of the polar jet stream, the tropopause is typically around 10Km high, with a very deep layer of stratosphere at roughly constant temperature (of -60°C). Equatorward, the tropopause is at 16-17 Km (and has a complex structure), with temperatures as low as -70°C. The jet stream forms the geostrophic wind that maintains the pressure gradient between them.

        Very large differences in temperature can be maintained in the atmosphere, up to the radiating layer, unlike Venus where lateral temperature gradients are tiny by comparison.

        The results of this will presumably vary depending on circumstances, but given that Venus lacks a surface rotation, and what atmospheric rotation it has is mostly concentrated at the equator, it really can’t be used as an analog for Earth.

      • AK: If you assume a pressure gradient without a geostrophic wind, wind will start to blow from high pressure to low, get deflected by the Coriolis effect, and continue to bend until it reaches equilibrium as the Geostrophic wind.

        When the contours are NS, the wind will start to blow EW. But the Coriolis effect for circular motion about the same axis as the Earth’s rotation is zero, whence no deflection.

        So how can wind follow NS isobars?

        Do you have a reference that supports/explains your account?

      • Ok, I’ve now read the rest of your explanation. To begin with, you don’t distinguish between EW and NS pressure isobars. The Ekman effect only happens with the former, because wind caused by the latter experiences no Coriolis effect.

        But in the big picture the former is the main direction anyway, due to decreasing surface temperature with increasing latitude.

        Your account is more traditionally described as follows.

        In each hemisphere, from latitudes 0 to 30° the NS pressure gradients (EW isobars) induce the largest Hadley cell, which rises at the equator, turns poleward (from hot to cold, as you say), sinks at 30°, and flows back to the equator.

        The Coriolis effect gives rise to jet streams

        https://en.wikipedia.org/wiki/Jet_stream#/media/File:Jetcrosssection.jpg

        and trade winds

        https://en.wikipedia.org/wiki/Trade_winds#/media/File:Map_prevailing_winds_on_earth.png

        as follows. It drives the upper poleward flow east (westerly subtropical jet stream at the tropopause at 30°) and the lower equatorward flow west (pole-easterly trade winds at the surface in the tropics where “pole” is according to hemisphere).

        The Hadley cell induces a smaller counter-rotating Ferrel cell at 30-60° which sinks at 30° and rises at 60°. The Coriolis effect is stronger there, in proportion to sin(latitude), and drives the upper flow west (joining the easterly trade winds as the flow descends to the surface at 30°) and the lower flow east (experienced as equator-westerly trade winds at the surface then rising to become the westerly polar jet stream at the tropopause at 60°).

        There is lastly a yet smaller polar cell above 60° which behaves like the Hadley cell in terms of directions. While it has extremely strong winds these play a less significant role in travel and commerce.

        Now if we take your account to be equivalent to the traditional one, then we can ask what would happen if Earth stopped rotating.

        The cells would continue since they’re driven by the EW isobars. But absent any Coriolis effect the trade winds would run NS and there would be no jet streams.

        I don’t see how that difference would make Earth more vulnerable to Venus’s fate.

      • Not sure why those two figures (from the respective Wikipedia articles, qv for credits) didn’t show up inline. Try again:

        Jetstreams:

        http://clim.stanford.edu/jetstream.jpg

        Trade winds:

        http://clim.stanford.edu/tradewinds.jpg

      • When the contours are NS, the wind will start to blow EW. But the Coriolis effect for circular motion about the same axis as the Earth’s rotation is zero, whence no deflection.

        Nope. EW motion also has a deflection (or force), due to increase/decreased tangential velocity and thus centrifugal force. It took me a while to internalize this when I first heard about it, but on a rotating disk it doesn’t matter which direction you go, the deflective force is the same.

        If you move toward the center, your tangential velocity is greater than that you’re moving into, and you’re deflected in the direction of rotation. If you move away from the center, you’re deflected in the opposite direction from rotation.

        If you’re moving in the direction of rotation, you’re deflected away from the center, due to greater centripetal force from higher tangential velocity (than whatever balances the force from the original rotation). If you’re moving in the direction opposite to rotation, you’re deflected toward the center, due to lesser centripetal force from lower tangential velocity.

        Remember, there’s already something balancing the tendency for a rotating object to fly off in a straight line. In the case of the Earth, it’s because the surface is tilting slightly towards the poles. That is, if you follow a northwards path exactly normal to your perceived “downwards”, you’ll actually be getting a little closer to the center of the earth. That “downhill tilt” exactly balances the usual centrifugal force from the Earth’s rotation.

        AFAIK it’s all explained in more precise terms in the links I gave above.

      • @AK: That is, if you follow a northwards path exactly normal to your perceived “downwards”, you’ll actually be getting a little closer to the center of the earth.

        Yes, that’s the case we agree on. Please focus on the case of an EW or latitude-preserving path.

      • Yes, that’s the case we agree on. Please focus on the case of an EW or latitude-preserving path.

        The point is that NS tilt exactly balances the centrifugal force when moving exactly at the speed of the Earth’s rotation. If you move eastward, you’re moving faster, and the added force pushes you uphill: south in the Northern hemisphere. If you move westward, you’re moving slower (than the Earth’s rotation), and the reduced centrifugal force fails to entirely balance the tilt, so you are pushed downhill: north in the northern hemisphere.

      • @AK: If you move toward the center, your tangential velocity is greater than that you’re moving into, and you’re deflected in the direction of rotation.

        Replacing “center” by “axis of Earth’s rotation”, this effect is in proportion to sin(latitude). No complaint there. In the Northern Hemisphere you’d be deflected to the right whether moving north or south.

        If you’re moving in the direction of rotation, you’re deflected away from the center, due to greater centripetal force from higher tangential velocity

        Hmm, good point (though I would have said greater centrifugal force). This too is in proportion to sin(latitude).

        In particular, in the Arctic where sin(latitude) is close to 1, everything is being thrown outwards. But that would create a vacuum over the North Pole which acts to suck it back in, so eventually an equilibrium is reached where the centrifugal force is balanced by the pressure of the atmosphere surrounding the Arctic, i.e. poleward pressure from a lower latitude constituting the balancing centripetal force. But a westerly (meaning from the west) will have additional rotational velocity and therefore additional centrifugal force and therefore tend to deflect to the right. Likewise an easterly will have less rotational velocity and therefore also deflect to the right.

        The situation you described earlier of a cold column surrounded by warm air is that of a cold core cyclone with inward pressure. This will generate an inward flow all around, all of which will be deflected to the right in the NH (left in SH), thereby setting up counterclockwise rotation around the column, which will then become the eye of the cyclone. A warm core cyclone should flow outwards and therefore rotate the other way.

        So it looks like you’re right that the effect is independent of whether the pressure is acting NS or EW. Which is consistent with John Nielsen-Gammon’s notes on geostrophic wind.

        In light of Venus’s 400 kph easterlies blowing around the planet, what geostrophic effect would you expect on Venus?

      • In his book, Storms of My Grandchildren, Hansen seems to think we can turn into Venus.

        ***** SPOILER ALERT ******

        He has a sub-chapter where he delves into science fiction. Aliens intercepting Earth’s radio signals decide to visit. When they reach Earth, they think they have confused the coordinates with Venus’s.

    • russellseitz

      Republican perseverence in refusing to adduce policies governeed by the facts, and continued political subservience to donors who do free markets the disservice of eliding corporate and national interests.

      • Rubbish

      • Bullpucky… Far more money and vested interests in the CAGWunist camp. Some pigs are more equal than others…

      • Russ, your rabid ideology is clouding your cognitive functions. Take 2 Pirins and lay down. It will pass.

      • Don Monfort

        Poor russy. He hasn’t got the word. EPA Admin admits in testimony before Congress that the decreed policies of the Obama Admin, that has been in power for six years, will do virtually nothing to reduce alleged AGW warming:

        CHAIRMAN LAMAR SMITH: “On the Clean Power Plan, former Obama Administration Assistant Secretary Charles McConnell said at best it will reduce global temperature by only one one-hundredth of a degree Celsius. At the same time it’s going to increase the cost of electricity. That’s going to hurt the lowest income Americans the most. How do you justify such an expensive, burdensome, onerous rule that’s really not going to do much good and isn’t this all pain and no gain.

        ADMINISTRATOR GINA MCCARTHY: “No sir, I don’t agree with you. If you look at the RIA we did, the Regulatory Impact Analysis you would see it’s enormously beneficial.

        CHAIRMAN SMITH: “Do you consider one one-hundredth of a degree to be enormously beneficial?”

        ADMINISTRATOR MCCARTHY: “The value of this rule is not measured in that way. It is measured in showing strong domestic action which can actually trigger global action to address what’s a necessary action to protect…”

        CHAIRMAN SMITH: “Do you disagree with my one one-hundredth of a degree figure? Do you disagree with the one one-hundredth of a degree?”

        ADMINISTRATOR MCCARTHY: “I’m not disagreeing that this action in and of itself will not make all the difference we need to address climate action, but what I’m saying is that if we don’t take action domestically we will never get started and we’ll never…”

        CHAIRMAN SMITH: “But if you are looking at the results, the results can’t justify the cost and the burden that you’re imposing on the American people in my judgement.”

        US House Science Committee
        July 9, 2015
        Read more at http://www.liveleak.com/view?i=559_1437054944#SiXLXzixS2SuAgGF.99

        So the policies implemented by your greenie Dem heroes, russy, are separated from what the hated denier Repubs have done, by one one hundredth of a degree.

        Why do you suppose the Dems didn’t tackle the alleged existential climate threat when they controlled the whole government, russy? Doesn’t that make you angry, russy?

      • Oooh, Russell likes to use big words.

      • Just love this part from Gina McCarthy:

        ADMINISTRATOR MCCARTHY: “The value of this rule is not measured in that way. It is measured in showing strong domestic action which can actually trigger global action to address what’s a necessary action to protect…”

        Here is the appointed head of a major government agency admitting that the new rules her agency wants to implement are nothing more than a feel good measure, which “can actually trigger action to address a necessary action”.

        I know 4th graders who can talk more intelligently than that.

        And since I know them from my time doing science education and Junior Achievement, I’m also willing to bet they have a better understanding of science and economics than Ms. McCarthy.

    • Bravo! Examining the table of contents of the essay, there is no mention of “Cooling” as a possible outcome. The essay is fatally flawed by this omission. Cooling is possible; it has happened before; the “pause” may be temporary or the top of a wave. The combination of cooling and government policy (taxes, supply limits, cost) can be deadly to vulnerable citizens. The risks of cooling are not addressed.

      King, Sir David, Professor Zhou Dadi, Professor Daniel Schrag, Professor Qi Ye, and Dr Arunabha Ghosh. “Climate Change: A Risk Assessment – Projects – Sciences & Technology in the Service of Society.” Science? Centre for Science and Policy, July 13, 2015.
      http://www.csap.cam.ac.uk/projects/climate-change-risk-assessment/

      Ward, Victoria. “Winter Death Toll ‘to Exceed 40,000.’” News. The Telegraph, February 1, 2015.
      http://www.telegraph.co.uk/news/weather/11382808/Winter-death-toll-to-exceed-40000.html

      • Pooh, Dixie

        Nuclear Energy: (For those who wish to move their nuclear rook). In the United States, there have been 9 nuclear reactor incidents since 2003, inclusive, through the last update Feb 21, 2015.
        Of these 9:
        – Four have been mechanical or electrical equipment failures without release of radioactive material, with 1 fatality from a non-nuclear construction accident.
        – Five released radioactive material into the environment, primarily tritium, strontium, and one report of spillage of 35 L of highly enriched uranium. This is about 0.5 per year

        The following are lists of all incidents:

        Wikipedia contributors. “Nuclear Reactor Accidents in the United States.” Wikipedia, the Free Encyclopedia, February 21, 2015.

        http://en.wikipedia.org/w/index.php?title=Nuclear_reactor_accidents_in_the_United_States&oldid=648161768

        Wikipedia contributors. “List of Nuclear Power Accidents by Country.” Wikipedia, the Free Encyclopedia, January 31, 2015.
        http://en.wikipedia.org/w/index.php?title=List_of_nuclear_power_accidents_by_country&oldid=644767173

      • russellseitz

        This Pooh of little brain has not done her homework :
        Here, verbatim, is the primary conclusion of the report from King, Schrag et al. :

        “1. What we are doing to the climate is emitting greenhouse gases that trap heat and warm it
        up. Whether those emissions go up or down in future will depend mainly on the policy choices we make, and the technological progress that expands our options. Our best guess at the moment, based on current policies and trends, is that emissions will keep going up for another few decades, and then either level off, or come down slowly. This is for two reasons: governments are not making maximum use of the technologies
        to reduce emissions that we already have; and technology is not yet progressing fast enough to give governments the policy options they will need in the future. In the worst case, emissions could keep on rising throughout the century.
        2. How the climate may change, and what that could do to us, are both highly uncertain. The important thing to understand is that uncertainty is not our friend. There is much more scope to be unlucky than there is to be lucky.
        For any pathway of emissions through time, there are wide ranges of possible increases in global temperature and sea level. On a high emissions pathway where the most likely temperature increase is estimated to be 5°C by 2100, anything from 3°C to 7°C may be possible. However, while on this pathway the chances of staying below
        3°C will become vanishingly small over time, the chances of exceeding 7°C will increase, and this extreme outcome could become more likely than not within the following century. Similarly, there is very little chance that the global sea level rise will slow down from its current rate, and every chance that it will accelerate – the only question is by how much. While an increase of somewhere between 40cm and 1m looks likely this century, the delayed response of huge ice-sheets to warming means we may already be committed to more than 10m over the longer term – we just do not know whether that will take centuries or millennia..”

      • On a high emissions pathway where the most likely temperature increase is estimated to be 5°C by 2100, anything from 3°C to 7°C may be possible.

        The highest thirty year trend observed is around 1.9C per century.

        The highest trend of any duration through 2014 is around 1.7C per century.

        If you believe the temperature trends are mostly due to RF, then you should be prepared to answer why you believe any future trends would be so much greater than what we observe.

        http://climatewatcher.webs.com/TrendsSince.png

      • Pooh, Dixie

        russellseitz | July 21, 2015 at 1:13 pm

        My critique was directed at the lack of alternative explanations of observations. Further, the “nuclear” references addressed “the maximum use of technologies” in King, Schrag et al.

        As for the King, Schrag paper itself, I observe foregone conclusions, a disregard of climate history, and a generous helping of scary stories.

        As for “homework”, my data base has grown to >6200 articles and papers, most cross-referenced and tagged.

        Thanks for playing.

      • “Cooling is possible;”

        In fact, it’s even plausible.

  2. Pingback: Risk assessment: What is the plausible ‘worst scenario’ for climate change? | Enjeux énergies et environnement

  3. This roughly 10 feet of sea level rise

    Observations are around 10 inches of SLR per century, some of which is unrelated to temperature, so yeah, accountability would be good.

    • Do you know how much is due to aquifer depletion? IIRC, someone posted something that estimated it to be something like .7mm/yr.

    • Anyone have any info on the rise of the floors of the oceans?

      • Dunno about the volume of ocean basins, but it is kinda interesting to look at this chart of horizontal motion rates ( ~ 50mm/year ) compared to SLR rates ( ~3mm/year ). Constants that aren’t and variables that don’t:
        https://cimss.ssec.wisc.edu/sage/geology/lesson2/images/concepts_fig14.gif

      • Changes in land height are usually much greater than changes in sea level at most locations

      • RS – why then are the seas posing a problem? Seems that the whole issue is sea level rising relative to sea shore. Seems to me that a bit of geology is in order. Plate tec and underwater extrusion of the molten subcrust is what I am suggesting needs to be addressed – not just the melting of Antarctica and the rest of Greenland.

      • Good gawd… read Mitrovica. If you think they missed something that erases the problem, think again.

      • JCH

        The charts you posted clearly show that the trend during the satellite era has shown a pretty consistent rate of rise that would equal about a foot over 100 years. There are accelerations and decelerations that have lasted over a year during that time. If we get a sustained increase in the rate that lasts a couple of years there would be indications of a change in the trend.

        Alarmists have been seeks this increased trend for years, but no luck yet huh

      • Geographic Variability of Sea-Level Change by Robert E. Kopp, Carling C. Hay, Christopher M. Little, Jerry X. Mitrovica Curr Clim Change Rep doi: 10.1007/s40641-015-0015-5

        Local sea-level changes differ significantly from global-mean sea-level change as a result of (1) non-climatic, geological background processes; (2) atmosphere/ocean dynamics; and (3) the gravitational, elastic, and rotational “fingerprint” effects of ice and ocean mass redistribution. Though the research communities working on these different effects each have a long history, the integration of all these different processes into interpretations of past changes and projections of future change is an active area of research. Fully characterizing the past contributions of these processes requires information from sources covering a range of timescales, including geological proxies, tide-gauge observations from the last ~3 centuries, and satellite-altimetry data from the last ~2 decades. Local sea-level rise projections must account for the different spatial patterns of different processes, as well as potential correlations between different drivers.

      • JCH – U ended with the “latest” 6-year “look”. Apparently, if the time period is short enough period and the latest slope can be going “one way” or the “other”, you can get tremendous “mm/y” rates (~10mm/y, if you looked at the case when the “current observation point” was 2013 and only the previous year was considered. Projections for 35-85 years from now are “long-term” events. To me, the last 6 years is not a good “pointing stick”. Having pointed out how variable the year-to-year rates are in the satellite data, I would not expect any short span to be useful – only multi-decade data where the last few decades deviated significantly from the trend of the previous many decades without any “offsets” seem appropriate.

      • Joel Williams | July 21, 2015 at 1:32 pm | Reply
        Anyone have any info on the rise of the floors of the oceans?

        Huh???

        What is generally assumed is that the ocean floor is sinking and the land is rising during the interglacial (during the ice age the land sinks and the ocean floor rises).

        http://sealevel.colorado.edu/content/what-glacial-isostatic-adjustment-gia-and-why-do-you-correct-it
        “Averaged over the global ocean surface, the mean rate of sea level change due to GIA is independently estimated from models at -0.3 mm/yr (Peltier, 2001, 2002, 2009; Peltier & Luthcke, 2009).”

        This effect is called GIA – glacial isostatic adjustment. It wasn’t important enough to correct for until 2011 when the sea levels weren’t rising fast enough to suit some people.

        Satellite sea level trends have an artificial 0.3 mm/y added to them to account for the estimated sinking of the sea floor. Given that they are measuring sea level not the volume of the ocean this is sort of a crazy thing to do. The GIA adjustment is the sea level equivalent of the land temperature adjustments (which are known as CGAGW – computer generated anthropomorphic global warming).

        If the stated sea level change estimated by satellites is 3.2 mm/y the actual estimate of the sea level rise is 2.9 mm/y.

      • @RS: Changes in land height are usually much greater than changes in sea level at most locations.

        Hardly surprising given that height of anything is measured with respect to sea level.

      • JCH can’t even do dueling graphs right.

      • The graphs show a slight acceleration in SLR over a period that was previously thought to show a slight deceleration.

        That is the latest research.

        The acceleration makes sense versus other data. The deceleration never did. Even PA, because of groundwater depletion, thinks the period should have shown an acceleration. The AVISO graph for the short period adds the vertical spike that has occurred in 2015.

        There was a slight acceleration up to 2015. Add in the vertical spike and, gee, what?

        The papers I’ve read indicate they do not expect to see an acceleration until around 2015, so to see one now is early.

        So yeah, yet again, it’s worse than they thought.

      • SB 2025.

      • JCH | July 22, 2015 at 10:05 pm |
        SB 2025.

        http://www.psmsl.org/data/obtaining/rlr.monthly.plots/2126.png

        http://www.psmsl.org/data/obtaining/rlr.annual.plots/2126.png

        http://www.energy.ca.gov/2012publications/CEC-500-2012-039/CEC-500-2012-039.pdf

        Santa Barbara sea level change, “1.25 +/-1.82 mm/y” according to the report. The high tide is about 5 feet.

        Umm…. The sea level in Santa Barbara is doing something…

        Californians have an odd fascination with fixing problems they don’t have.

        Even PA, because of groundwater depletion, thinks the period should have shown an acceleration.

        As far as the global sea level… I’m in wait and see mode. There are too many moving parts. Till about 2050 I would expect it to accelerate – then we start running out of fossil groundwater and it may slow to the 20th century average.

        If there isn’t an acceleration then either the ice sheet melting or/and steric warming are decreasing. If the satellite and tidal gauge data converge it is the ice sheets, if they don’t, it is steric.

        If the warmers are right the sea level is going to take off like a banshee. But to get to 1 meter in 2100 (vs 1900) is going to take an acceleration of about 0.138 mm/y2. That is a substantial increase.

  4. Return to Ice Age type conditions.

  5. Hansen actually predicted a rise of up to six metres by 2095. . Why is he still seen as a credible scientist?

    https://books.google.co.uk/books?id=nNevrsC831IC&pg=PA16&lpg=PA16&dq=hansen+predicts+sixteen+feet+rise&source=bl&ots=rF-yNXaebm&sig=bPGdLhY4KzGHDK7qBxfvaONsnMo&hl=en&sa=X&ved=0CCUQ6AEwAmoVChMI2N63pN_qxgIVxtMUCh1cSQ3c#v=onepage&q=hansen%20predicts%20sixteen%20feet%20rise&f=false

    We have all manner of Important people predicting dire things. I suppose that’s how they manage to grab the attention of the media and politicians. We need to look to the past to determine what could happen in the future if globally we reached the sort of temperatures experienced at times during the Holocene.

    Tonyb

    • read

      [Response: I don’t think that ‘likely’ is the right characterisation of Hansen’s thoughts, ‘plausible’ might be a better description. I am not particularly persuaded of this (and I certainly don’t think that > 2m by 2100 is ‘likely’). That isn’t to say I have a huge amount of confidence in lower estimates – the tools that could quantify these numbers more precisely do not yet exist (though they are being developed). The second part of your comment – that SLR will be driven by (West) Antarctica and Greenland is true and the impacts are not going to be linear in temperature. That doesn’t really help pin down the actual number though. – gavin] – See more at: http://www.realclimate.org/index.php/archives/2013/11/sea-level-rise-what-the-experts-expect/#sthash.CmmdpeZJ.dpuf

    • Abstract
      Paleoclimate data help us assess climate sensitivity and potential human-made climate effects. We conclude that Earth in the warmest interglacial periods of the past million years was less than 1°C warmer than in the Holocene. Polar warmth in these interglacials and in the Pliocene does not imply that a substantial cushion remains between today’s climate and dangerous warming, but rather that Earth is poised to experience strong amplifying polar feedbacks in response to moderate global warming. Thus, goals to limit human-made warming to 2°C are not sufficient—they are prescriptions for disaster. Ice sheet disintegration is nonlinear, spurred by amplifying feedbacks. We suggest that ice sheet mass loss, if warming continues unabated, will be characterized better by a doubling time for mass loss rate than by a linear trend. Satellite gravity data, though too brief to be conclusive, are consistent with a doubling time of 10 years or less, implying the possibility of multimeter sea level rise this century. Observed accelerating ice sheet mass loss supports our conclusion that Earth’s temperature now exceeds the mean Holocene value. Rapid reduction of fossil fuel emissions is required for humanity to succeed in preserving a planet resembling the one on which civilization developed.

    • Tonyb,

      I think the link is broke. What is the name of the book?

      I read his “Grandchildren” book. Lot’s of whining, but at least one good idea. The funny thing is, if the warming fwaidycats want to accept Dr. Hansen’s ideas that’s good – lets build the big nukes and get on with it. We can all have a big party together and congratulate ourselves for avoiding thermageddon. Unfortunately, the whole issue is a big, nasty knot – politics, values, religion, corruption, crony capitalism, yada yada…

      • Justin

        Its called ‘if you love this planet’ by Helen Caldicott. page 15

        https://books.google.co.uk/books?id=nNevrsC831IC&printsec=frontcover#v=onepage&q&f=false

        tonyb

      • Helen Caldicott?

        Now THAT is funny! Decades ago, she scared the beejeebers out of me with her anti-nuke campaigns. I did my own investigations over the years and found out nuclear power isn’t that scary after all. :)

      • I can’t find her footnote, but he’s never predicted 5 meters of SLR.

      • Justinwonder

        When I first met Helen Caldicott she was a “Ban The Bomb”er speaking in emphatic tones with predictions of the future as in “Hell Fire & Brimstone.”
        Otherwise a rather pleasant women who used her medical credentials as a crusader, incorporating her husband’s radiation jargon, he, Bill being a radiologist, to lend credibility to an otherwise strident and inane message. Boston and other political connections helped keep her messages prominent. Boston Children’s Hospital has a very near and dear connectivity to the Kennedy family and she, that is Helen, as a Pediatrician at BCH, had access to politicians which, to my way of thinking, was her major resource and influence, certainly not the science of nuclear energy.

        Having moved on to climate change she believes that: America is the only country capable of leading the world from the brink of climate disaster. Politicians certainly like to hear of the omnipotence; stroke stroke stroke.

        Helen also believes that the rest of the world can not wish for the good life of American society so therefore the rest of the planet’s population must languish with a lot less; i.e. no McDonalds nor Starbucks.

        If you are a politician, and it really doesn’t matter what flavor you are, and like to be told how wonderful you are, please contact Helen Caldicott.

      • From the Independent of 2007

        “Record summer heat waves, melting glaciers, and droughts offer compelling evidence that rapid climate change is happening, and media attention on the subject of global warming has been extensive for the past couple of years, from Al Gore’s Oscar-winning documentary An Inconvenient Truth to the report published by the UN Intergovernmental Panel on Climate Change (IPCC) this spring. However, a group of six American scientists-including UCSB paleoclimatology professor David Lea(pictured above, left, with NASA’s James Hansen) -recently published a paper stating that the IPCC’s sea-level rise estimate of approximately 16 inches during the next century is too conservative.

        The group-led by James Hansen, of the NASA Goddard Institute for Space Studies-predicts a sea rise of about 20 feet by 2100. The paper-which references nearly 100 scientific articles, publications, and statistical reports-unequivocally states that “recent greenhouse gas emissions place Earth perilously close to dramatic climate change that could run out of control, with great dangers for humans and other creatures.”

        The 29-page paper was published in the July 15 issue of Philosophical Transactions of the Royal Society of London, Series A-the oldest English-language scientific publication in existence. This is the second paper Lea and Hansen have collaborated on together. The first paper focused more on global temperature change, while this one scrutinizes sea-level rise specifically-a pertinent issue in coastal communities like Santa Barbara.”

        tonyb

      • http://sealevel.colorado.edu/content/regional-sea-level-time-series
        Above is a link where one can view a sea level history for Manhattan over past decades.

        This is a link to the 2001 Salon (eyeroll) interview which relates Hansen’s late 80s predictions to Bob Reiss of the WaPo (eyeroll again). There is some “uncertainty” over whether Hansen told Reiss 20 or 40 years for the period of prediction. I think all parties would now like 40. We all need a little time.
        http://www.salon.com/2001/10/23/weather/

        Would I put much trust in anything Hansen told me? Well, he’s the type to own an expensive chronometer, so maybe I’d take the time of day from him. Maybe.

        Btw, Hansen repeated his 5 metre prediction in a 2007 interview with the Australian ABC (eyeroll again). Of course, it came along with various conditional clauses by way of qualification…but Big Jim got his 5 metres in for the ABC (final eyeroll).

      • mosomoso

        Knowing how bad Nasa is with the metric system perhaps Hansen thought 5 metres was 8 inches?

        tonyb

      • What do we know about SLR? Well, there is the CU data and NOAA tide gauge charts. Nice. But what do we really know about WHY the rates of rise are as they are? Some wonderful papers suggesting and hypothesizing about why the increase. So there are estimates that Groundwater Abstraction makes up 25% of the rise.
        But could it be 30 or 35%. Hydrothermal vents could be contributing a little heat from the unknown thousands. But do we really know? How much more from the non-Antarctic glaciers as they dwindle in size. How much of the West Antarctica peninsula glaciers loss is from geothermal activities? Some papers make estimates but do they really know? There are still too many unanswered WHY questions.

        Sometimes doing our best is still not good enough.

      • Something from a newspaper is not a scientific prediction written by Hansen. Why do you insist upon doing this? What drives this?

      • What Hansen wrote is in papers available on the NASA website. What I would not trust is people who persistently distort what he said. If you’ll distort that, you’ll distort anything; therefore, you are not to be trusted.

      • Come on JCH, you should know us better than that. You seem to have a blind spot with regards to Dr Hansen.

        This is the Royal Society paper I referenced earlier that the Independent quoted.

        He gave this speech in 2007 with dire warnings for a decade or so in future, as you can see in the Royal Society paper and has also talked of albedo flip and whipsaw

        http://rsta.royalsocietypublishing.org/content/365/1856/1925

        ‘In my opinion, multi-meter sea level rise will occur this century, if the huge business-as-usual climate forcing actually occurs.’
        (multi means many)

        http://www.columbia.edu/~jeh1/mailings/2013/20130926_PTRSpaperDiscussion.pdf

        He also said this

        http://blogs.plos.org/retort/2013/12/03/qa-with-james-hansen/

        ‘Well, you know, the paleo data doesn’t allow you to see a discernible lag between the global temperature changes and the sea level changes, so it doesn’t give you any confidence that there’s going to be a big lag.’

        he is a believer in very lare sea rises this century. Why do you have a problem with that?

        tonyb

      • Tonyb,

        “.,.he is a believer in very lare sea rises this century. Why do you have a problem with that?”

        Because he knows, you know, and I know that is what Hansen claims, and it is obviously silly and discrediting. It makes Hansen look alarmist, which is what he is. I read his book, I know what Hansen is trying to say. The poor man has probably (plausibly?) had nightmares due to his investigations of Venus. We are not on Venus.

      • Tony, if you’re predicting less of a rise than Hansen is predicting based on linear extrapolation from some point in time, why not pick 1000 AD as that point and extrapolate linearly from there? This should make your reasoning even more compelling.

      • Vaughan

        I am not trying to make any sort of prediction, just trying to get to the root of Hansen’s prediction. His followers don’t seem to believe what others have interpreted his talks and papers to mean.

        it would be good to have some sort of clarity from people such as jch.

        tonyb

      • You’re the one with the blind spot. I don’t distort what he’s said. If you want to discredit him, and you have not, then you need to do some Paleo work. So far no significant group of Paleo sea level scientist seems to agree with you that Hansen is discredited; in fact, many of the most significant Paleo sea level scientists are either coauthors with Hansen or frequently coauthors with Hansen’s coauthors.I don’t see them running away from him.

    • Well, if you believe an ground water study about 1/2 of the real sea level (1.7 to 1.9 mm/y) rise is ground water depletion. This will show up as land sinking and ocean rising in satellite studies for a 2x change in sea level even though virtually all the sinking land is in Timbuktu and not near the coast.

      Hansen’s warming isn’t going to affect that. Given that the sea is warming a little and we will continue to deplete groundwater – actual sea levels (the tidal gaugey things) will be 7-11 inches higher in 2100.

      The current ice sheet melting is about 1/10 of the satellite sea level rise or less..

      • From what I have read groundwater is net negative until 2015. Now.

      • jch

        No one is trying to discredit Hansen, merely to understand what he is saying. Many people -including Caldicott and the sympathetic journalists at the Independent-have interpreted his remarks as meaning multi meter sea level rise. He said that.in the Columbia paper I referenced above

        Please tell us your understanding of Hansen’s position on sea level rise by 2100. Its a perfectly reasonable request.

        tonyb

      • http://arstechnica.com/science/2015/05/bias-in-satellite-measurements-hid-recent-sea-level-rise-acceleration/

        arstechnica is the source of a lot of global warming hooha.

        However this article provides a useful piece of information.

        The IPCC 1 meter sea level prediction requires a sea level acceleration of 0.07 mm/Y. Hansen’s prediction would require a higher acceleration.

        http://sealevel.colorado.edu/files/2015_rel2/sl_ns_global.png

        Given the 23 year lack of a discernable acceleration of the 3.0 mm/y trend (3 mm is just for show), there doesn’t seem any point in discussing the disaster scenarios until there is some acceleration. The 0.07 mm/Y required by the IPCC would mean a 18 mm higher sea level (above the level from the 3.0 trend) and a change in the annual rate of increase of 1.6 mm per year. The increase didn’t happen. After 2016, which will probably be a repeat of the 2011 La Nina, there will be no reason.

        Until the sea level rise increases 50% (to 4.6 mm/y) none of these predictions have any credibility. That is the change in the sea level rate of increase that should already have happened.

        The SDPs (satellite data processors) are already adding at least 0.3 mm of CGSLR (computer generated sea level rise) so the difference we are looking for has to be greater than the adjustments the SDPs think they can get away with. The current sea level rise is due to ground water extraction, some residual ocean heating, a little post LIA ice pack melting, and reading the geode funny.

        If the satellite sea level is still around 3.0 (3.3-0.3) mm or less in 2020 these claims should be discarded. The sea level will continue to rise until we run out of ground water.

      • Have you ever lifted hay bales onto a wagon going up a hill on the flat prairie?

      • PA – you’re really not up to taking on the likes of JPL and Caltech.

        he is saying Paleo research implies the possibility.

      • JCH

        You know that there has been virtually no increase in the rate of sea level rise and no reliable information to support the notion that sea level will rise by more than a meter between 2000 and 2100, but you continue to spout garbage. Try being honest.

      • In fact, sea level rise has dropped to 1/2 of what the average is over the last 20,000 years.

        The sea has risen 120 meters over the last 20,000 years.

        Take 120 multiple by 1000 (to convert to millimeters) and divide by 20000:

        (120 * 1000)/20000 = 6 mm

        The average rate of sea level rise over the last 20000 years is 6 mm per year.

        We are only at 3 mm per year or 1/2 of the background average rate.

        So nothing much to worry about in my opinion.

        Of the last 8 inches of sea level rise (since 1900) how much would have happened anyway, naturally?

        Probably at least half (4 inches) and maybe 2/3 (1.9mm of 3 mm is almost 2/3).

      • And no reasonable person thinks there should be a large acceleration. Again, have you ever picked up hay bales on a hill on the flat prairie. The only part of your body that perceives the hill is your aching back. My Dad’s baler would screw up and make double bales. What fun at 100 plus.

        You demand something that makes no sense, so you don’t count. Sorry. It’s 2015, and it’s not 2030.

      • Jch

        Still hoping to get your interpretation of hansens predicted sea level rise by 2100

        This article seems to be suggesting ten feet in the next fifty years

        http://news.nationalgeographic.com/2015/07/150721-james-hansen-sea-level-rise-climate-change-global-warming-science/

        What do you believe Hansen to be suggesting?

        Tonyb

      • JCH | July 22, 2015 at 1:09 pm |
        PA – you’re really not up to taking on the likes of JPL and Caltech.

        he is saying Paleo research implies the possibility.

        Actually I am and it is game on. The paleo research is so bad you can argue anything. There are still people who claim the PETM was caused by a CO2 increase – which happened 5k years after the start of the event.

        http://www.cmar.csiro.au/sealevel/images/CSIRO_GMSL_figure.png

        http://www.globalwarming-sowhat.com/_Media/groundwater-depletion-1900_med_hr.jpeg

        http://podaac.jpl.nasa.gov/OceanEvents/2015_03_25_GroundwaterChanges
        California’s Sacramento and San Joaquin river basins have lost roughly 15km3 of total water per year since 2011

        http://onlinelibrary.wiley.com/doi/10.1029/2011GL048604/full
        Since 1960 the groundwater contribution to sea level is over 10% and rising. From 2000 to 2008 (8 years) groundwater contributed 3.2 mm to the sea level rise which according to the UofC raw data was 23 mm. So about 14%. of the increase was groundwater.

        http://onlinelibrary.wiley.com/doi/10.1029/2010GL044571/full
        we estimate the total global groundwater depletion to have increased from 126 (±32) km3 a−1 in 1960 to 283 (±40) km3 a−1 in 2000.

        It is pretty clear that the groundwater depletion is having a significant effect on sea level. The estimates run from about 0.4mm to over 0.78 mm per year and that is just for the year 2000.

        It sort of is what it is. Groundwater should be causing a significant increase in the sea level rise – and it isn’t that noticeable. This is bad news for the sea level surgers because they require an accelerating sea level rise above the amount caused by increasing groundwater depletion and it just isn’t there.

      • Points:
        1. Nice graph but it sort of makes my point that the sea level rise should be accelerating. I don’t have any fundamental arguments with the graph but some satellite/model analysis points to greater depletion.

        2. Groundwater is fossil (ie not replenished in our lifetime). Further the groundwater depletion is a 2x effect since the satellites see the land as sinking (it isn’t just sea up – it is sea up/land down)..

        3. The IPCC seems to really need a 0.09 mm/Y or greater acceleration to achieve their 1 m between 1900 and 2100. There was about 200 mm rise in 20th century, there will be a 300 mm increase (all things being equal) in the 21st century. To hit one meter in 2100 (85 years away) requires a 500 mm increase or an acceleration of .138 mm/y2. This would require the rate of sea level rise to increase 1.38 mm/y each decade. Hansen’s 5 meters would require an acceleration of 1.25 mm/y2.

        4. 0.056 mm/y2 acceleration between 1993 and 2015 is a 14 mm increase in sea level between 1993 and 2015. That is not illustrated.

        5. 0.058 mm/y2 is a 1.2 mm/y increase in the rate of sea level rise (1993-2015). That isn’t apparent either.

        6. Perhaps if you illustrated the total 1993-2015 increase in sea level in mm (no rates) or stated how much of the post 1992 sea level rise in mm was due to acceleration we could go further. I am uncertain how much change you believe the acceleration made.

      • The papers I’ve read are not really looking for an acceleration until 2025 – 2030. They’ve detected an acceleration now. Early.

      • Visit this again, the spike:

        http://www.aviso.altimetry.fr/fileadmin/images/data/Products/indic/msl/MSL_Serie_MERGED_Global_IB_RWT_GIA_Adjust.png

        data:

        2014.838994 7.000013e-02
        2014.866142 7.159981e-02
        2014.893289 7.342505e-02
        2014.920437 7.485197e-02
        2014.947584 7.529790e-02
        2014.974732 7.469553e-02
        2015.001879 7.368248e-02
        2015.029027 7.322499e-02
        2015.056175 7.389672e-02
        2015.083322 7.541822e-02
        2015.110470 7.688421e-02
        2015.137617 7.749194e-02
        2015.164765 7.707515e-02
        2015.191912 7.621789e-02
        2015.219060 7.583069e-02
        2015.246207 7.624534e-02
        2015.273355 7.707953e-02
        2015.300503 7.790628e-02
        2015.327650 7.854787e-02

        Almost to 8.

      • We’ll see.

        The current El Nino is a feel good moment for the strong warming community. Next year’s La Nina won’t be.

        Picking an El Nino year and going “its accelerating, its accelerating” is fine but doesn’t really prove much. The sea level dropped 8 mm in the last La Nina.

        You really have to pick ENSO neutral points where the positive/negative periods are 50/50.

        The ENSO neutral periods are pretty close to the trend line. The 2002-2007.5 period was ENSO positive except for a brief blip you can see in the sea level data.

        What surprises me is the trendlessness of the data. If the sea is warming, the ice is melting, and the land is pumped dry at increasing rates the trend should be accelerating rapidly. Doesn’t seem to be happening. Even a 1 meter 2100 sea level demands that 2025 have a 4.0 mm/y rate of sea level rise (4.3 mm/y for the GIAers). I could see it going to 3.2 (3.5 with GIA) from the groundwater trend. Which means the acceleration would have to cause 4.2 mm/Y (4.5 w/GIA).

        To me it seems that half the rise is steric and half is ice/groundwater. The melting ice and groundwater are 2x from a satellite point of view – which would explain the satellite trend being about 50% too high. Steric expansion isn’t stealing mass from elsewhere so to a satellite it is 1X.

  6. ‘Worst Scenario’ excludes no monsters under the bed.

    How about ‘Most Likely’ scenario?

    Global CO2 emissions appear to have peaked in 2013.
    This could be a one off, but 2013 was also the year that in China ( the source of most CO2 emissions growth in the 2000s ) working age population peaked:
    https://qzprod.files.wordpress.com/2013/09/china-s-working-age-population-percent-of-total-population_chartbuilder-1.png

    As with most of the developed nations, emissions of CO2 will decline in step.

    • way too uncertain for a most likely scenario

      • Plausible: Professional alarmists are what they appear to be, self seeking, propaganda spewing careerists.

        Possible: They’re honest and sincere and really believe this twaddle about the coming apocalypse..

        (aka pokerguy)

    • A conservative scenario for BAU is that CO2 per capita stops growing and remains flat as the population rises to 10 billion, so emissions rise at the population rate. That gets us to near 700 ppm by 2100. Like I say, this is conservative by not assuming CO2 per capita will continue to grow as it has, and it assumes no reduction in CO2 per capita. By the time you add in the other GHGs and aerosols this is much like RCP6.

    • Hi TE. Over at 3000 Quads I have been making the case for several years that future emissions have in fact been underestimated by organizations like the DOE’s EIA and the IEA.

      They have consistently projected energy consumption to grow at 2.4% in the developing world as a whole. In fact, consumption has grown at about 4.19% with no sign of slowing.

      Those who look at China’s current economic troubles as a hopeful sign that their heavy emission days are over would do well to look at what happened to U.S. emissions during the Great Depression.

      It is incumbent on us to choose the portfolio of fuels to provide energy that is least damaging to the environment–and the economies of the developing world.

      Not easy.

      • Those who look at China’s current economic troubles as a hopeful sign that their heavy emission days are over would do well to look at what happened to U.S. emissions during the Great Depression.

        Well, much was different then, but the US during the Great depression still had a growing population:
        http://www.immigrationeis.org/sites/default/files/images/charts/graph_us_population_1790_2010.gif

        Here is China’s history and projections:
        http://www.kkr.com/images/insights/10-images/charts-27.png

        Is that the stuff of a one-off blip in the road? China’s growth,energy, and CO2 emissions would seem likely to decline for half a century or more.

        And that’s not all. India’s population has been slowing faster than expected and now appears set to fall to less than replacement fertility within five years.

        It is incumbent on us to choose the portfolio of fuels to provide energy that is least damaging to the environment–and the economies of the developing world.

        damaging to the environment“?

        Given that carbon dioxide is the basis of most of the life in the environment and that greater abundance of carbon dioxide appears to foster greater life within the environment at least at the rates we observe, there would not appear to be a significant basis for “damage to the environment”.

      • China’s growth,energy, and CO2 emissions would seem likely to decline for half a century or more.

        My god, man, you should sell China short. Over that period of time you’d make out like a bandit!

      • Given that carbon dioxide is the basis of most of the life in the environment

        If by “most” you mean plant life then in part yes. Our carbohydrates come from plants via the miracle of photosynthesis which converts CO2 to carbohydrates, benefiting both plants and vegetarians.

        For all of life, plants included, along with artificial life like internal combustion engines, CO2 is the basis of life only in the sense that poop is the basis of life, but even more so.

        Engines, animals, and plants all oxidize carbon-based fuels 24/7, producing CO2 as their waste product. The oceans convert CO2 into harmful carbonic acid, the rocks convert it into (ultimately) useful limestone, and the plants convert it more directly into immediately useful carbohydrates.

        Were it not for the plants, CO2 would not be the basis of life in any plausible scenario of “life’.

      • Hiya TE,

        Comparing trends of total pop to working age pop is not going to lead to enlightenment. China’s population is actually still growing, as is their income and the migration of people from electricity free villages to the cities.

        They’re building 346 coal plants now. There’s a reason.

      • thomaswfuller2 | July 22, 2015 at 12:55 am |
        Hiya TE,

        Comparing trends of total pop to working age pop is not going to lead to enlightenment. China’s population is actually still growing, as is their income and the migration of people from electricity free villages to the cities.

        They’re building 346 coal plants now. There’s a reason.

        Let’s see. Is that a fact or a factoid.

        China has 620 coal plants that produce 3785 TWh from 758 GWe of capacity. Gross electric production was 4994 GWh in 2012. They have closed 71 GWe of coal capacity since 2006. All 4 of the major Beijing coal plants will have been shut down and replaced with gas by next year. 150GWe of nuclear planned by 2030 (Wiki says 200 GWe installed 2030 and 400 GWe installed 2050).

        The average coal power station (758/620) is about 1220 GWe. China likes to build 500-600 GWe coal plants (and seem to have a taste for nuclear in the same size) so presumably the bulk of their power stations are twin plants. The coal plant capacity factor 57% (they get over 87% from nuclear). The 200 GWe of nuclear in 2030 is the equivalent of 305 GWe of coal generation.

        China supposedly is going to add 1,583 GWe of generation by 2030. Half is supposed to be renewable. 150 GW is going to be nuclear. 346 coal plants represents about 208 GWe of coal generation which leaves 434 GWe which will be a mix of things but mostly gas.

        The current 74% coal fired generation is expected to drop to 55% by 2030. If the 346 new plants are twin generation facilities they will be a little over, if they are 600 GWe plants they will be significantly under. 55%.

        Don’t know – depends on how many coal plants they retire but at the current rate of coal plant retirement it isn’t going to be that big a difference. They are adding about as much nuclear as coal.

      • Comparing trends of total pop to working age pop is not going to lead to enlightenment.
        Yes, working age population is very important.

        Isn’t it true that in macro-economics consumption=production?
        If so, production decline is baked in the cake, improved only by productivity increases. The young earn no income and the old earn “fixed” income and both young and old depend on the working age production for all they consume.

        China’s population is actually still growing

        Not for long. Population has an important leading indicator: Fertility Rate.
        China’s fertility rate ( 1.66 in 2012, 1.5 in 2014 ) is significantly less than replacement rate ( 2.1 for developed nations, 2.3 for undeveloped nations ):
        http://cdn.theatlantic.com/static/mt/assets/hua_hsu/cohen_fertility3.jpg

        , as is their income and the migration of people from electricity free villages to the cities. Most of that has already occurred. A problem with Chinese competitiveness now is that wages have risen so as to reduce the cost advantage of Chinese production. China’s economy is not going to disappear and I’m happy for Chinese that have improved living standards, but this story stands out because of the rapid growth from trade that’s now meeting a global story of ageing demographics. This is what’s already happened in Japan, what’s happening in Europe, and Singapore, and India and what would be happening in the US were it not for high rates of immigration. How rapidly this occurs in Africa and undeveloped Asia remains to be seen, but it’s a big deal.

      • Hello TF.

        They’re building 346 coal plants now. There’s a reason.

        Think Progress ( yes, TP ) reports:
        “In 2014, China cut domestic consumption of coal by 2.9 percent, the first drop in more than a decade, with coal production also falling 2.5 percent.”

        That drop appears to be accelerating so far this year:

        “The analysis, published by Greenpeace and Energydesk China, reviewed data from a number of sources, including China’s industrial output, and found that China had reduced its coal output by 6.1 percent in the first four months of 2015. “

        Now, evidently, hydro-power increased in 2014 from a wet year.
        And China signed the deal with Putin for Russian natural gass.
        But I certainly believe the demographics underlie a continuing secular trend.

      • To all who are looking at China’s reporting on coal usage–I would advise waiting for a year or so. They often make huge adjustments in those totals.

    • Well, there are a couple of issues that don’t get considered:
      http://static1.businessinsider.com/image/53712e4f69bedde31684d4c3-854-673/screen%20shot%202014-05-12%20at%203.56.27%20pm.png

      1. The cost to get oil out of the ground in a well in Texas or Saudi Arabia is about $10/barrel. The new sources are considerably more expensive. This applies to other fossil fuels.
      2. Higher cost (long term) reduces consumption. Global warmers haven’t repealed the law of supply and demand. However, short term, people have to get to work tomorrow and use their air conditioner so short term demand is somewhat inflexible. But when energy is expensive the next car or next apartment is a different story.
      3. High fuel prices depress economic activity (though not as much as renewable energy).
      http://image.slidesharecdn.com/outlook2015-vkwbrussels-03december2014-141205032050-conversion-gate02/95/outlook-2015-vkw-brussels-03-december-2014-6-638.jpg

      4. Economic growth is below historical averages. In fact it has declined steadily since the 1940-1970 period. Perhaps the price to pay for all those environmental regulations. If not for the boom in China, emissions would be below 8 GT/Y today.

      5. Transport of coal is more expensive than mining it. Coal is used in quantity in countries that have it. India is really the only country with coal reserves that can increase consumption significantly. And India seems to have chosen nuclear. India consumes about 1/10 the coal of China. India has over twice the population density of China and simply can’t follow the Chinese emissions curve.

      6. Environmental absorption is accounting for over 55% of emissions – this year it will again exceed 60% (it did in 2011).. The ten year average CO2 increase is 2.02 PPM/Y. The CO2 increase in 1977 was 2.10 PPM with only about 1/2 of the current emissions (4.9 GT vs 9.8 GT). According to CDIAC 6.716 GT of emissions were absorbed by the environment in 2011. The land portion of absorption is the most variable and depends to some extent on how much rainforest they burn in a given year. Brazil only burned about 40% of their average in 2011 and Indonesia had a slow year. The annual variation in rainforest destruction affects the net land absorption over 1 GT/Y. And Indonesia is almost tapped out on rainforest to burn.

      7. China is the smartest large country on the planet. They were suppressed by government control of the economy. Changing the market rules took the top off the pop bottle. There simply isn’t going to be a repeat of their 20 year growth.

      It is what it is. Future emissions will be in the 10-14 GT range. Less than 40% will stay in the atmosphere. Hard to see the CO2 level getting much over 460 PPM with emissions declining after the 2030s (and when China runs of coal in the 2030s emissions will decline).

      • 4. Economic growth is below historical averages.

        Yes. In addition to the factors above, I believe demography is a key component.

        GDP = P * Pr

        P is population, Pr is productivity
        P is really working age population.
        Holdren expands this identity to include energy and CO2 terms.

        But what happens to GDP ( and subsequent energy and CO2 ) when P begins decreasing?

        That’s what’s happening in large portions of the world.

      • Well…

        The trends seem to point toward 9-11 Billion by 2100 so I don’t believe low reproduction is a problem.

        The whole global warming thing could be a preemptive first shot at limiting population growth. They were fishing for a excuse to choke off development.

        Climate science is so badly regulated that you can claim anything and nobody checks (or your buddies that agree with you check).

        Red team hostile review of government funded climate studies should be required law. People who do bad science (a lot of global warmers) should be debarred from government grant programs..

  7. Rcp8.5 is impossible. The more I look at it the more I’m starting to consider the chain of events which led to its creation as scientific fraud.

    • I agree, RCP8.5 is horrific, but unlikely. Fast population growth (mostly in Africa!), slow tech development, slow GDP growth, and a massive increase in world poverty, It is a reasonable “worst plausible case”, and so illustrates why governments seldom plan for such dire outcomes.

      For a bit more analytical look at some of the assumptions behind RCP8.5 see Is our certain fate a coal-burning climate apocalypse? No!.

      • RCP 8.5 (the emissions curve we are closest to) predicts a 2.6 PPM CO2 increase this year and 3.0 PPM by 2020.

        I predict this year’s CO2 increase will be less than 2 PPM and the increase in 2020 will be less than 2 PPM.

        To achieve RCP8.5’s 940 PPM level in 2100 would require an average for the 21st century 5.7 PPM/Y. Given that the first 15 years have averaged 2 PPM it now requires 6.35 PPM/Y. By 2020 (which looks like it will still be 2 PPM) RCP 8.5 will require an average of a 6.6 PPM/Y CO2 increase for the remainder of the century.

        It doesn’t take much analysis to realize that RCP8.5 is a joke.

      • PA,

        “RCP 8.5 is a joke”

        That seems unfair, to put it kindly. Considering extreme scenarios is a necessary part of risk management. The papers describing RCP8.5 imo do so fairly and reasonably, as does AR5.

        That it’s sometimes misused by activists and journalists (e.g., as the inevitable result of failure to enact policies forcing decarbonization) does not make it a joke. In the climate wars it seems likely that every aspect of science will get misused, eventually.

      • EOTFMW

        The RCP 8.5 were created in 2011 and updated in 2013. Yet it still anticipates 2.6 PPM atmospheric CO2 growth in 2015.

        The 6.35 PPM/Y needed for the rest of the century to hit 940 PPM would have to peak around 10.7 (given we are at 2 PPM now).

        10.7 PPM/Y is 22.8 GT/Y. Given that 60% of emissions are going into the environment (6 GT) and at 500 PPM this would be about 11 GT this really represents 30.8 to 33.8 GT/y.

        There are 760 GT of fossil carbon in fuel reserves. 30+ GT would burn through them in 26 years and significantly increase prices. .

        What makes it unrealistic is that other sources (nuclear mostly) would be much cheaper at that level of consumption. Particularly given that new energy sources have extraction costs of $50 /barrel or higher.

        Ask any engineer what doubled or tripled fossil fuel costs would do to the energy market.

      • PA,

        “Yet it still anticipates 2.6 PPM atmospheric CO2 growth in 2015.”

        I suspect few experts would consider that a serious problem on a 90 year forecast. However, I agree with you that RCP8.5 is an unlikely scenario. But then that’s its role in AR5.

        “There are 760 GT of fossil carbon in fuel reserves. 30+ GT would burn through them in 26 years and significantly increase prices.”

        That’s only sort of so. Energy companies, the primary source of accurate data on reserves, have no interest in calculating total world reserves. They closely estimate what they’re working, and lightly estimate wheat they own. Also, many nations consider this data to be State secrets. So we’ve already burned through some past estimates of total reserves.

        On the other hand, several studies suggest that world coal reserves are grossly overestimated, largely due to overestimating the BTU content of the ore (much is more like Kitty Litter than anthracite). I haven’t updated this file since 2007, but FYI:

        Coal: Resources and Future Production“, Energy Watch Group, March 2007 (47 pages, PDF)
        The Future of Coal“, B. Kavalov and S. D. Peteves, Prepared for European Commission DG Joint Research Centre Institute for Energy (JRC IFE), February 2007
        COAL OF THE FUTURE (SUPPLY PROSPECTS FOR THERMAL COAL BY 2030-2050)”, Energy Edge Limited, Prepared for the European Commission – DG Joint Research Centre Institute for Energy (JRC IFE), February 2007
        Coal: Research and Development to Support National Energy Policy“, National Academies, June 2007 — Summary. The full copy is aprox $40.

        “Ask any engineer what doubled or tripled fossil fuel costs would do to the energy market.”

        That’s also only sort of so. There is an inverse relationship between ore quality and quantity. So mineral prices have a tendency to rise over long periods of time as lower quality or more difficult to extract ores are tapped. But technology reduces cost. So the net trend in prices (after inflation) is difficult or impossible to estimate. For more about this see an excerpt from the great British mining expert Ronald Prain’s classic Copper.

      • EOTFMW

        The whole energy industry issue is interesting.

        New finds seem to increase on a one to one basis to match consumption.

        However the cost of new reserves is increasing rapidly.

        I’m not sure about coal reserves in general but about 50% of US coal reserves (28% of global coal) are legally/practically unextractable.

        Also the yield of reserves (% actually extracted) varies from 50% to 90%.

    • I think that calling its creation “scientific fraud” is quite unfair to Riahi et al. You should go read their paper that describes its construction – Riahi et al “RCP 8.5 — A scenario of comparatively high greenhouse gas emissions” (2011).

      Without going into the detail in their paper they describes RCP 8.5 as “the upper bound of the RCPs” and “a relatively conservative business as usual case”.

      I would add that the term “business as usual” isn’t used to describe RCP8.5 in either of the relevant IPCC AR5 WG1 Chapters (1 or 8).

      The problem comes with those that come later.

    • “Considering extreme scenarios is a necessary part of risk management.

      Do you have insurance for alien invasions?

      “extreme scenarios” sound vaguely familiar.

      Oh, yeah, same said Hansen:

      “Emphasis on extreme scenarios may have been appropriate at one time, when the public and decision-makers were relatively unaware of the global warming issue, and energy sources such as “synfuels,” shale oil and tar sands were receiving strong consideration. Now, however, the need is for demonstrably objective climate forcing scenarios consistent with what is realistic under current conditions. Scenarios that accurately fit recent and near-future observations have the best chance of bringing all of the important players into the discussion, and they also are what is needed for the purpose of providing policy-makers the most effective and efficient options to stop global warming.”

      In other words, we think the objective ( aka reality ) will be enough to scare people, so can stop talking about wildly unlikely stuff.

      Well, it doesn’t look like reality is scary.

      Hansen’s unintended confession above is evidence of appeal to emotion, not science.

      • “Do you have insurance for alien invasions?”

        Alien invasions would not be considered plausible unless the discussion was about an invasion on non-citizens. There are other better examples of cases where we could really buy insurance but choose not to because the probability of the disaster is considered low enough to not pay for the cost of the insurance.

        Looking at the situation from another perspective, people often do buy insurance that is a very poor investment. Extended warranties on products as an example are all designed as profit centers for those offering the insurance.

      • The “insurance” aspect is a useful paradigm.

        If car collisions insurance was 50% of your car’s value and you have an accident once every 10 years that costs 1/3 of the cars value what would you do?

        Before we put any money into mitigation we need to quantity:
        1. Risk
        2. Casualty loss.

        For climate change high loss requires extreme temperatures so the the risk is inverse to the loss.

        Analysis will probably prove that we have already taken sufficient steps to take the high loss/low risk scenarios off the table.

    • I think it is plausible. If it cools and food productivity drops we’ll find all kinds of inventive ways to use coal and extract coal and methane. We’ll probably set charges to release methane we can’t easily extract directly into the ocean and atmosphere, both to prevent cooling and fertilize the planet.

  8. The semantics of “worst case” seems to dominate the conversation about what is possible. Plausible seems to imply “as far as we know”. Worst case plausible scenario represents the catastroph’s talking points. And we have very intelligent people saying we should plan given this environment of unknowability.

    To me, the very worst case scenario is implementing plans formulated by people with long faces, a deep frown, and a propensity to exaggeration.

    Now where have I seen that just recently?

  9. Theodore Dalrymple, on how factoids, dodgy maths and ignoring all plus factors can manufacture the spooks and demons a propagandist needs. (However, unlike climate alarmism, the new germanophobia is based on only partial ignorance. At least there is such a place as Germany.)
    http://takimag.com/article/teutoxic_theodore_dalrymple

  10. So the previous predictions were not dire enough with a 2C GTA rise; now it needs to be upwards to 10C and seas 10-ft higher (actually a little comedown from the Scientific American’s 20-ft!). For those folks who have not seen the post below before, here it is again. The sea level data are those of the NOAA, not mine.

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Here is an evaluation of the NOAA satellite sea level data on a year-to-year basis (1993-2015) on a plot with the 1900-2000 historical data. Lots of extreme ups and downs in the yearly rates, but the rate for the 2 decades is fairly constant. An abrupt increase of the “flat satellite rate” to 2.87 mm/y over the “flat” historical one of 1.78 mm/y was “effected” in 1993.

    http://pages.swcp.com/~jmw-mcw/Sea%20level%20Historical%20plus%20satellite.jpg

    You can find the analysis of the NOAA 2-decade data at this URL:

    http://gsjournal.net/Science-Journals/Research%20Papers-Climate%20Studies/Download/6137

  11. Looking the the Table of Contents and the Executive Summary I think that the utility of this document is limited. That, of course, is different than mileage :)

    Plausible alternatives and scenario under each should be considered.

    The appropriate focus is the plausible worst case scenario, which has not been a focus of the IPCC or climate establishment.

    I disagree. This seems too (pre)cautious for an approach to a risk assessment. RA’s are not policies and are intended to inform the latter. :O) IMO plausible alternatives and scenarios under each should be considered. Otherwise forget it, you[one] are going nowhere.

    • correction:

      “Plausible alternatives and scenarios under each should be considered.

    • What would a risk assessment ‘focused on the plausible worst case scenario” tell you that would be useful in developing policy?

    • IMO Mark…nothing. The utility of a risk assesement is in the comparison of alternatives. Such an assessment (worst case) is a risk estimate…not a risk analysis.

      • Clarification: Such an assessment of a single scenario (worst case) is a risk estimate for that scenario…not a complete risk analysis.

      • If the worst case scenario isn’t very bad, then you don’t need a complete risk analysis. If the worst case scenario is ‘ruin’, you are playing a different game. Right now we have no idea what the plausible worst case scenario is

      • I see your point, but I do not know if I would want to start a new game carrying the baggage of the worst case scenario and nothing else. Such a worst case has to occur from an assumed action or alternative. There or other scenarios that may occur under that action and one of them may be catastrophic. So, simplifying things as an example I would want to perform an initial risk assessment that would would incorporate risks comparisons of likely outcomes/scenarios (bad and good) associated with a generic mitigation alternative, a generic adaptation alternative, and a generic no action alternative. Starting there would be easier–IMO.

        Also it seems to that we would have no idea of a worst case unless we look at multiple alternatives and associated scenarios. [Ha! Well, I should say ‘they’ instead of ‘we’…no way you could pay me enough to get into that game!]

      • Right now we have no idea what the plausible worst case scenario is

        They keep telling us what the worst case scenarios are.
        They don’t actually tell us about any actual plausible scenarios.
        They just don’t actually tell us about any likely scenarios.

      • Sadly, I think the emphasis on ‘worst case scenarios’ does not really serve our interests, especially if the worst cases are also the least likely.

        I think it would be extremely useful to have a graduated approach for a number of reasons. First, even if temperature and sea level rises prove to be high, given the stop-start nature of rises in GAT over the past century we can expect to spend a considerable period of time dealing with lower levels and whatever impacts they bring.

        Preparing a response to different levels of climate impacts would allow for a measured response. Sea walls built to deal with 98cm of sea level rise could easily build in a margin of 50%, which might be adequate overall if Nic Lewis is right, but would certainly buy us enough time to see if Hansen’s catastrophic nightmares have any chance of coming to pass.

        The same is true of other pre-adaptation measures. It is also true of attempts to mitigate climate change. Radically reducing coal usage in the developed world may actually be enough of a response, if sensitivity is low. But even if more will be required of us in the future, allowing the emerging countries to burn coal for the first decades of this century may be enough to generate the resilience they need to make cuts later if they are required.

        Furthermore, preparing for modest impacts now would also buy time for technological innovation to spare us from huge expenses now. Using the technology of 2040 to prepare for impacts in 2075 is likely to be just as effective and far less expensive than using what is available today.

        The activist side of the climate debate has consciously tried to maintain the world’s focus on outlier estimates of temperature climbs, sea level rise and sensitivity estimates. It keeps them in the news, allows them to shout denier and probably generates more funding for research.

        But it does not serve our needs.

      • Tom,

        Sadly, I think the emphasis on ‘worst case scenarios’ does not really serve our interests, especially if the worst cases are also the least likely.

        Very much so. I think it would work against our interest.

        I think it would be extremely useful to have a graduated approach for a number of reasons. and

        The same is true of other pre-adaptation measures. It is also true of attempts to mitigate climate change. Radically reducing coal usage…

        To me these seems hardly indistinguishable from an adaptive approach.

        The activist side … It does not serve our needs. No, but there is a lot that is not serving our needs.

      • popesclimatetheory

        They keep telling us what the worst case scenarios are.
        They don’t actually tell us about any actual plausible scenarios.
        They just don’t actually tell us about any likely scenarios.

        Guess ‘us’ better better off of us’e butt, roll up us’s sleeves, and do something.

        Seems Steven Mosher has been making that point for a while… :O)
        —-
        OT – In light of the recent vibes from Francis should you change your handle to popesclimatetheory I ?

      • Our hostess:

        “If the worst case scenario isn’t very bad, then you don’t need a complete risk analysis. If the worst case scenario is ‘ruin’, you are playing a different game. Right now we have no idea what the plausible worst case scenario is.”

        I think this highlights the problem I have with this post and the paper that is its subject.

        If we don’t know if we face a plausible ruinous risk what should we do? Should we plan for it or wait and see what happens (and focus our actions meanwhile on what we actually know)?

        From a public policy POV we should expect science to do its best to elucidate what’s going on. There is no place in this for precautionary principles or focusing exclusively on extreme outcomes. We (the public and the policy makers) want to know what’s likely, unlikely and unknown, not have the science used to support forecast of “possible/plausible” ruinous futures by scientist advocates.

        What should the policy maker do with this information?

        Well the first thing in a property owning democracy is to realise that private individual are in the front line of managing most of these risk, and their view of the risks (likelihoods and consequences) will be idiosyncratic. We expect our governments to help us to understand what we are facing but if collective ruin is unknown then let the effected individuals take a position. Coercion is well down the list. Remember we don’t know if ruin is upon us so protecting the powerless in ruin’s name is hard to argue.

        There will then those who believe the worst. They should be free to head for the hills, decarbonise their lifestyles and advocate for their beliefs. They should be equally free to leave out the first two actions.

        If the ruinous future is truly unknown where does that leave a government thinking about collective action? To the extent that any future is judged likely it is reasonable to act accordingly, but as the future becomes less well known any government needs to balance this uncertainty against the known adverse impact of regulation.

        Under these circumstances the political calculus ends up doing a bit here and a bit there in response to those that are worried but not too much to frighten the horses when it comes to those who remain unconvinced.

        And I personally think that response is about right for the situation we find ourselves in. No doubt the pendulum will shift as life goes on.

      • HAS, good take on this, adding to some good comments which undermine the “worst plausible scenario” approach. Faustino

      • Mwgrant,

        I agree. We should I put just as much emphasis on analysing the best case scenarios as we do on the worst case scenarios. For 25 years climate research has omitted looking into the opportunities and analysing the best case scenarios. Why is that?

      • curryja: Right now we have no idea what the plausible worst case scenario is

        My idea is that the plausible worst case scenario is that we will not be prepared for the range of weather documented for the past 150 years.

        The Indus Valley will experience alternations of flood and drought; the maximum flood in the next 150 years may exceed the maximum flood of the last 150 years by 10%. The plausible worst case scenario is that no one is prepared for a flood that is 10% smaller than the maximum over the last 150 years.

        Everyone talks about means and trends. In this discussion, the “signal” is the natural variability.

      • Popesclimatetheology

      • Matt, and NYC is probably overdue for a cat-5 that follows Sandy’s storm track during high tide.

      • @curryja: Right now we have no idea what the plausible worst case scenario is

        Agreed. Much better would be to base forecasts on the most likely scenario.

        As can be seen from the CDIAC data, fossil fuel emissions between 1750 and 2015 have been increasing exponentially. Approximately 40% of those emissions have remained in the atmosphere during those 265 years. This has increased atmospheric CO2 from about 280 ppmv in 1750 to about 400 ppmv today.

        If that exponential increase continues unabated, then as Hofmann et al pointed out in 2009, atmospheric CO2 will hit 1000 ppmv right around 2100 AD.

        The probability that atmospheric CO2 will be above 1000 ppmv in 2100 is therefore about 0.5.

        Is that too unlikely for you, Judith?

      • see my uncertainty monster for explanation of scenario uncertainty. Most likely implies that you understand the pdf. We don’t understand the pdf for climate outcomes – way too uncertain- we can merely formulate scenarios of the future. In the absence of a pdf, we ask the question as to whether we can bound the risk, hence my concern with the worst case scenario.

        Regarding the relation of emissions to actual CO2 concentrations, this is also rather uncertain, since the CO2 sinks increase with CO2 concentration and there is much we don’t know.

      • Vaughan Pratt

        “Is that too unlikely for you, Judith?”

        Given all your assumptions I for one think one needs to conclude “(t)he probability that atmospheric CO2 will be above 1000 ppmv in 2100 is therefore about 0.5” if that is any help.

        If we had eggs we could have ham and eggs, if we had ham.

      • Our good friend Max Anacker, 22/04/14 @ 5.56pm argues
        two constraints on the case by IPCC of CO 2 – 1000ppm
        by 2100.
        http://judithcurry.com/2014/04/22/coal-and-the-ipcc/

      • mathew and aaron,

        I agree. While both sides have polarized the public policy debate into futile attrition warfare, there are sensible measures we could take now. Preparing for the almost inevitable repeat of historical weather events should be at the top of the list. In the US, it’s not even on the list.

        For example, major east coast cities will be hit by severe hurricanes. Not just Miami, but NYC as well. The results will be predictable and horrific.

        “We don’t even plan for the past.”
        — Steven Mosher (member of Berkeley Earth; bio here), a comment posted at Climate Etc.

      • @curryja: We don’t understand the pdf for climate outcomes – way too uncertain- we can merely formulate scenarios of the future.

        Quite right. Admittedly the RCP8.5 scenario doesn’t come with a variance, but as long as one assumes it is not zero and the distribution is normal and centered on RCP8.5 itself, then under the assumption of RCP8.5 as the likely business-as-usual scenario it is reasonable to divide the event space evenly on each side of RCP8.5. With that assumption there is a 50-50 chance of exceeding 936 ppmv, the value of RCP8.5 in 2100.

        My assumption was the quite similar scenario of Hofmann et al 2009, which hits 1028 ppmv in 2100. With that scenario there is a 50-50 chance of exceeding 1028 ppmv in 2100, by the same reasoning.

        You’re quite right that we don’t know how to assign probabilities to the representative concentration pathways, and without picking one there is little that can be said about probabilities.

      • @bts: Our good friend Max Anacker, 22/04/14 @ 5.56pm

        Beth, for years Max argued about future CO2 on the assumption that 100% of it has been following an exponential law with a constant CAGR of 0.5%. From this he inferred a doubling time of 70/0.5 = 140 years.

        Max’s model fitted neither the theory nor the facts. The theory is that the exponential growth is not in the whole thing but only in the excess over the natural background level of 280 ppmv. By one estimate, that of Hofmann et al 2009, the CAGR of that excess is 2.155% (exp(0.693/36.2) to use their formula).

        This theoretical model fits the Keeling curve much more accurately than does Max’s model. It also hindcasts to earlier centuries far more accurately than Max’s model. And at least up to 2100 it is a not unreasonable theoretical model for the RCP8.5 “business as usual” concentration pathway, even though RCP8.5 wasn’t calculated that way. (Hofmann is below RCP8.5 up to 2075, then gradually pulls ahead and is 90 ppmv ahead by 2100.)

        RCP8.5 as the “business-as-usual” scenario is 468 in 2035 and 936 in 2100, thereby doubling in 65 years.

      • Vaughan Pratt

        “Admittedly the RCP8.5 scenario doesn’t come with a variance, but as long as one assumes it is not zero and the distribution is normal and centered on RCP8.5 itself, then under the assumption of RCP8.5 as the likely business-as-usual scenario it is reasonable to divide the event space evenly on each side of RCP8.5. With that assumption there is a 50-50 chance of exceeding 936 ppmv, the value of RCP8.5 in 2100.”

        The RCP scenarios are projections (i.e. simply a product of their assumptions) not forecasts. To speak of its variance is meaningless, it has none.

        If any of its assumptions are violated it ceases to be an accurate projection, but as I’ve noted elsewhere if you do choose to assume all the assumptions are true regardless you can have ham and eggs.

        Unfortunately the interesting questions for those looking forward to breakfast are: “Do we have ham?” and “Do we have eggs?”

        In this case if the underlying process isn’t exponential then the future won’t be an exponential extrapolation.

        The RCP8.5 projection/scenario isn’t occurring. So far it looks much more like the RCP4.5 & 6.0 scenarios. The assumptions behind RCP8.5 aren’t valid.

        The eggs are missing.

        “RCP8.5 as the “business-as-usual” scenario is 468 in 2035 and 936 in 2100, thereby doubling in 65 years.”

        RCP8.5 is not a “business-as-usual” scenario. I’ve noted elsewhere on this thread it is self-described as “the upper bound of the RCPs” and “a relatively conservative business as usual case” and AR5 WG1 nowhere describes it as “business-as-usual”.

      • RCP8.5 is not a “business-as-usual” scenario.

        Agreed.

        However as any high school student can see by looking at the Keeling curve, the excess of CO2 over the preindustrial level of 280 ppmv has been growing exponentially (that is, as a geometric progression when looking at the annual time series) ever since measurements were begun in 1958.

        “Business as usual” is nothing more complicated than the continuation of that exponential growth. This growth is easily seen by plotting log2(CO2 – 280) since 1958, which gives the following.

        http://clim.stanford.edu/BusAsUsual.jpg

        To within an R2 of 99.77% this is a straight line with a slope of 0.0319, that is, a doubling time of 1/0.0319 = 31.35 years. To convert this to a CAGR simply multiply by 70. 70*0.0319 = 2.233. That is, the compound annual growth rate of the excess over 280 ppmv when estimated in this way is 2.233%.

        AR5 WG1 nowhere describes it as “business-as-usual”.

        But FAR (= AR1) did. I’d be interested to know why the IPCC stopped doing so in later assessments. Did they replace it with a different “business-as-usual” scenario or did they have some more fundamental objection to the term?

        Extrapolating a geometric progression seems a pretty obvious concept. What’s wrong with taking that as the definition of “business as usual”?

        Plugging 2100 in for x in the formula y = 0.0319x – 57.339 shown in the above graph gives y = 9.651, and 280 + 2^9.651 = 1084 ppmv. This is the expected CO2 in 2100 when “business as usual” is defined as “continued exponential growth of the excess over 280 ppmv”.

        RCP8.5 is around 100 ppmv less, and I’m not aware of any compelling reason to consider it a “business as usual” scenario other than that it is fairly close to the above exponential continuation.

      • Wondering about why the IPCC dropped the term “business as usual” after FAR, it occurs to me that it could be read as blaming business for rising CO2, which the IPCC might have judged as a tad tactless. Not all businesses generate CO2, and not all CO2 is generated by business (think of military jets, passenger cars, climate feedbacks, land use changes, etc.).

        If so then perhaps those who continue to use the term should follow the IPCC’s example and be a little more tactful by referring to it instead as “the continued exponential growth of excess CO2” (understood as the excess over 280 ppmv). Since that growth to date is modeled to within an R2 of 99.77% as an exponential, one need not look deeper into the underlying processes to justify that concept, which (a) is based solely on the exponential growth of excess CO2 to date (i.e. just ham, no egg), (b) unlike its close cousin RCP8.5 comes with a small variance implied by its R2, and (c) unlike RCP8.5 doesn’t require a spreadsheet of its values over the centuries since it can be computed as simply 280 + 1.022^(y − 1795), close enough for something that everyone agrees is just a reference point anyway and not necessarily a reliable forecast.

      • VP

        RCPs as their name implies are concentrations, CO2 emissions are just an input. You will see from Fig 6 of “The representative concentration pathways: an overview” van Vuuren et al (2011) the RCP8.5’s assumed CO2 emissions are a long way from exponential. They decelerate from 2070.

        The reason FAR used different terminology for its emissions scenarios is that it used equilibrium climate scenarios rather than RCPs. The latter were only introduced in 2009 for AR5. FARs emissions scenarios are quite different in construction than AR5s RCPs.

        If you read Rignot (2011) which is available on line you will have a better understanding of these issues.

      • HAS: the RCP8.5’s assumed CO2 emissions are a long way from exponential.

        How did CO2 emissions come into this?

        As usual I have not been clear. I am in full agreement with you about ham and eggs: if we had ham we could have a ham and egg sandwich, if we had eggs. If your point there is that there are many assumptions underlying the processes conjectured to be driving rising CO2, then yes, absolutely.

        I am not interested in any of them.

        My candidate for the reference point closest to RCP8.5 pays no attention to ham, eggs, volcanoes, aliens, or CO2 emissions, none of which can be shown to be exponential.

        In particular the CDIAC estimate of CO2 emissions since 1750 is far from exponential, showing a CAGR on the order of 15% during the latter half of the 19th century but considerably less than that during the 20th century. Furthermore the CAGR of CO2 emissions has been wandering all over the place throughout the 20th century and on into this one.

        Just to rub this in, if CO2 does have more than one exponential driver, then unless they all differ from each by at most a mere constant factor their net effect cannot be exponential because it is mathematically impossible for the sum of distinct exponentials to be an exponential.

        What I’m proposing is to look at one thing, and one thing only: the CO2 concentration itself, ignoring all possible drivers of it, exponential or not.

        Its excess over 280 ppmv has been growing very nicely at a straightforward exponential rate whose CAGR, in stark contrast to that of CO2 emissions, has held remarkably steady at 2.2% over the past half century.

        If we knew more about the drivers we could forecast a departure from this steady CAGR.

        But since the drivers present us with a complicated story that is hard to piece together, and even those pieces do not take into account the terrestrial and ocean sinks, climate feedbacks, etc., I propose ignoring all the possible drivers—ham, eggs, volcanoes, aliens, and the rest—and replacing the problematic notion of “business as usual” with the very simple concept of continued exponential growth of excess CO2.

        Whose simple formula is 1.022^(y − 1795). (Add 280 to get total atmospheric CO2, good for the last few thousand years.)

      • Steven Mosher

        VP

        “What’s wrong with taking that as the definition of “business as usual”?

        Stop being practical and logical !!!

      • Steven Mosher in response to VP: “What’s wrong with taking that as the definition of ‘business as usual’”?

        “Stop being practical and logical !!!”

        Hardly practical and logical when the authors of RCP8.5 have gone out of their way to create at a lower level of granularity a projection/scenario that says it isn’t business as usual. Rather as they note it “corresponds to a high greenhouse gas emissions pathway compared to the scenario literature .., and hence also to the upper bound of the RCPs”.

        It would be more practical and logical to define it as what it is.

      • HAS: It would be more practical and logical to define it as what it is.

        Indeed. It is what it is.

        This tautology is nicely summarized here as

        This is commonly used in American culture as an apathetic response to something that makes little sense or has little to no validity.

        Not a bad analysis of RCP8.5.

      • VP on tautologies.

        Fortunately as should be obvious I am not of American culture and know the difference between the content rich process of applying a meaningful label to a term (call it what it is) and asserting tautologies (“it is what it is”).

        To say that RCP8.5 is the upper bound of RCP scenarios contains information.

        Saying:
        “If ‘business as usual’ is ‘continued exponential growth of excess CO2’, RCP8.5 is ‘business as usual’, therefore RCP8.5 is ‘continued exponential growth of excess CO2′” is a tautology and therefore content free.

        Just like your arguments above that I labelled “ham and eggs”.

        Now there’s a tautology for you.

      • HAS, since you’re being so careful with terminology I’ll follow suit.

        Define “continued exponential growth of excess CO2” as 1.022^(y − 1795).

        Hopefully you don’t view that as a tautology.

        And for those who want to continue using the term “business as usual”, define it as “continued exponential growth of excess CO2”.

        This function of year y, plus 280, is more or less interchangeable with RCP8.5 for this century, so either will serve much the same purpose.

    • “The appropriate focus is the plausible worst case scenario”

      That makes sense but only if also considering the timeline in determining plausibility and implementation of responses. As an example consider sea level rise. It has been rising at roughly a rate of 1 foot per century for hundreds of years.

      If someone fears that sea level will rise by a meter by 2100, isn’t it reasonable for the increased rate of rise to be observed for an extended period before considering the higher rate of rise as something more than just remotely plausible? Even after the increased rate of rise was exhibited for several years there would be lots of time to respond.

      • Yes, I think that there will be quite a bit of back and forth here about the idea of using a “plausible worst case scenario”. If people stay focused and keep it civil it could be constructive.

      • What would an increase in SLR look like between 2000 and 2020?

      • An acceleration… What would it look like?

      • JCH–you know the answer. A sustained rate of increase substantially higher than the rate since the satellite era began.

      • And since ground water extraction has accelerated for more than a century, we would expect to see accelerating sea level rise, even if temperatures were constant:
        https://legacy.cnx.org/content/m41397/latest/graphics17.png

      • JCH–you know the answer. A sustained rate of increase substantially higher than the rate since the satellite era began. …

        It will be barely detectable, and grow at a barely detectable rate. It probably should not be detectable in 2015, but there are definite hints of it.

      • JCH writes- “It will be barely detectable, and grow at a barely detectable rate.”

        To get even 1 meter of sea level rise by 2100 the rate of rise will have to more than triple. You are wrong to believe it would be barely detectable if it occurred. I greatly doubt we will get 1 meter of rise by 2100.

      • Rob,

        You are wasting your time. JCH can’t do arithmatic. Well, more likely he can, but refuses to do it, because he knows it knocks the bottom out of his position. So instead he posts colorful graphs.

  12. There is another level to risk assessment. The assumption here is that we face only one serious risk. This is, of course, quite false.

    * There are multiple geological risks — many highly likely over the 21st century horizon used by the IPCC.

    * There is the ongoing destruction of the oceans’ fisheries.

    * There is the massive effort required to mitigate the damage from population growth, which the latest UN forecast gives as 80% odds of between 9.6 and 12.3 billion people by 2100 (Gerland, P. et al, Science 10 Oct 2014).

    In 10 minutes we could like a dozen more. What is the cost of minimum prevention or mitigation of the “plausible worst case” for all of these? Probably a lot more than we will spend. Perhaps more than we can spend.

    This is a commonplace problem in the securities industry. Portfolio risk can be meaningfully assessed only at the total (i.e., portfolio) level. The reasoning is different than with environmental risk, but the logical conclusion is the same.

    Instead we look to fund risks based on the most successful fear-mongering by special interest groups. It’s a method not likely to work well for us.

    • Agree with this. In New Zealand we face possible issues around coastal erosion in the face of sea level rise, but we also need to be worried about Tsunami, siesmic risks and volcanoes (we don’t have snakes).

      The good thing that people forget about the risks of climate change is that they are progressive and emerge slowly. Even the discontinuities that people worry about (eg Antarctic sea ice collapse) are functions of the gradual increase in temperature.

      So in risk management we have the option of doing nothing. Real options analysis of these kinds of risks often come back and tell us that is the best option.

      And one needs to add that the consequences of a decent Tsunami, earthquake or volcanoes down here are likely to be much greater than the built environment retreating over 100 year time spans or our primary industries adjusting to different environments (all on the assumption that the extreme projections are valid). Anyone who has seen the marine terraces created around our capital city Wellington will get things in proportion.

      • HAS,

        Thanks for the real-world application of this, and the broader context to the discussion of risks!

      • If we do nothing and the worst case comes to pass, people will adapt, likely in ways we can’t imagine today. When, in the past, I tried to imagine the future, I imagined jet packs, flying cars, and space travel. Instead I got the iPhone. Meh.

      • justinwonder

        To be clear “doing nothing” isn’t quite, well, “doing nothing”. You are giving time to see how thing evolve.

        If we wait a decade with a slowly evolving uncertain risk there is a cost if we acquire evidence during that period that some form of action is required, but this needs to be weighed against the marginal cost of delaying a bit and the benefits gained by not acting if we instead acquire evidence that the risk wasn’t that bad.

        This is particularly true in evaluating unverified claims of extreme scenarios.

        Sea level rise is a case in point. The high risk is to property likely to be subject to erosion, much of which has notional 50 year life spans. Right now sea level isn’t behaving as the high risk scenarios for 100 years out would have us believe, so waiting a decade means has a very low cost (particularly if property owners are well informed). If someone builds now their property will be at the end of its life before it ends up at risk.

        On the other hand there is very high cost associated with enforced action now based on the high risk scenario.

        Given another decade of climate history we will hopefully be in a better position to judge what is happening, and if not might decide it is better to wait yet another decade.

      • HAS | July 21, 2015 at 4:43 pm |
        justinwonder

        To be clear “doing nothing” isn’t quite, well, “doing nothing”. You are giving time to see how thing evolve.

        Well, the people making the disaster claims have a lousy predictive track record. There isn’t any proof their forcing, co2 level, feedback, or harm claims have merit. Their sea ice and temperature predictions have been misses.

        Given that nothing much has happened for 15 years it is prudent to wait until somebodies predictions start tracking with the observed climate.

        We don’t know that 2100 will even be warmer than today. That would make any anti-warming actions counter-productive.

      • Better analyses are needed but an adaptive approach–and to me what is being discussed is one–seems most attractive. The approach is not really “no action” because at some level(s) things continue to be monitored.

      • Given another decade of climate history we will hopefully be in a better position to judge what is happening, and if not might decide it is better to wait yet another decade.

        Indeed. In 2020 it will appear based on temperatures during 2010-2020 that 2100 will fry at 5 °C higher, while in 2030 a hiatus will be claimed leading to freezing in 2100.

        Anyone looking at anything less than 20-year climate is kidding only themselves and their followers.

      • Vaughan Pratt
        “Anyone looking at anything less than 20-year climate is kidding only themselves and their followers.”

        Agreed.

        That’s why waiting another 10 or 20 years before leaping to conclusions in light of uncertainty is sensible.

      • Vaughan Pratt | July 22, 2015 at 1:37 am |

        Indeed. In 2020 it will appear based on temperatures during 2010-2020 that 2100 will fry at 5 °C higher, while in 2030 a hiatus will be claimed leading to freezing in 2100.

        We’ll see.

        From what I can tell the UHI is significant and about the same order as the CO2 forcing.

        The nature and solar trends seem to be heading in the other direction.

        But there is another issue to consider:

        http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.gif

        http://data.giss.nasa.gov/gistemp/2011/
        http://data.giss.nasa.gov/gistemp/2011/Fig2.gif

        http://www.climate4you.com/images/GISS%20MaturityDiagramSince20080517.gif

        Since a 2011 graph on a page updated in January 2012 (3 1/2 years ago) the post 1960 warming has increased 0.1°C degrees. The difference between 1907 and 2010 has increased about 0.16°C and the difference between 1998 and 2010 increased about 0.02°C.

        Now if we project that trend they will have a 3.88°C increase from adjustments alone just between the early 1900s and 2010 in 2100. Further the 2020 data will presumably be 0.03°C warmer than 2010 from adjustment alone.

        This makes predicting the 2020 trend based on the surface data sets somewhat challenging.

      • @PA: From what I can tell the UHI is significant and about the same order as the CO2 forcing.

        As Hansen, Russell, Lacis et al pointed out in 1985, the oceans are taking up most of the heat resulting from CO2 forcing.

        So in order to understand the impact of UHI it makes sense to look at the three trend lines of HadSST3 (sea surface temperature) before, during, and after the hiatus, as shown here.

        http://clim.stanford.edu/SST.jpg

        The hiatus in the middle, covering the decade 2001-2011, is clearly visible

        Before it there is a dramatic rise in sea surface temperature.

        After it there is an even more dramatic rise.

        This UHI you speak of is presumably from activity in the Lost City of Atlantis, which after great hyperactivity prior to 2001 would appear to have gone dormant for a decade, then revived at an even higher level of hyperactivity.

        If you have yet more details about Atlantis, a huge audience out there awaits you. Asking a million dollars for an article on what you know about Atlantis would be short-changing yourself.

    • Ed, HAS, yes, I made a similarly point briefly before reading other posts. Faustino

    • Thanks for reminding me why I stopped subscribing to FM.

    • oldfossil,

      Perhaps you could explain to us why you disagree with my comment describing the textbook method of risk assessment — to allocate funds by a risk budget based on a broad perspective, rather than ad hoc evaluation of individual cases.

  13. A prediction of extremes is now more newsworthy than any actual occurrence, while talk of past extremes is as welcome as loud belch in a crowded lift.

    Inhabiting the future is a present neurosis. We need to stop living in a cheesy disaster movie. Science needs to open windows, step outside, get its feet wet. Perfect curiosity driveth out neurosis.

  14. Don Monfort

    The title of the paper should be: If that other crap didn’t scare them, maybe this will.

    More pre-Paris desperation.

    • Maybe he is angling for a gig as technical advisor to the next Hollywood diaster movie.

  15. Don Monfort

    “Parts of [our coastal cities] would still be sticking above the water,” Hansen says, “but you couldn’t live there.”

    You only lose the bottom floor. That’s about 1% of a 100 story building, if my calculations are correct. Venice on the Hudson. Venice on the Thames. The tourists will love it.

  16. > I just spotted a post by Blair King entitled On RCP8.5 and the business as usual scenario, which also challenges the plausibility of RCP8.5.

    Providing arguments might have been better.

    • Don Monfort

      Please keep that stuff on the bickering thread, willy.

      • “Challenging” was too big tell, Don Don.

        Have you found anything else than “but Mr. T” and “but CAGW” in Judy’s editorial?

    • Steven Mosher

      Arguments:

      http://link.springer.com/article/10.1007%2Fs10584-011-0149-y#page-1

      8.5 is implausible

      1. No Mitigation target: we currently have targets..
      2. Increased reliance on Coal. Coal is dying
      3. Energy intensity improvement of .5%. History is around 1%
      4. learning rates for renewables below 10%. All known learning
      rates for solar exceed 15%
      http://eea.epri.com/pdf/epri-energy-and-climate-change-research-seminar/2013/2013_08.pdf
      5. Coal increases 10 fold….. ya right

      I wont talk about the population assumptions… 12B is plausible.

      Basically 8.5 is not plausible because U have to imagine that we lost the climate debate, when in fact we won it.

      Most plausible worst case is RCP 6 emissions with a sensitivity of 4.5C

      • Better.

        The death of coal might be a bit :

        Coal provides around 30.1% of global primary energy needs, generates over 40% of the world’s electricity and is used in the production of 70% of the world’s steel.

        […]

        Total world coal production reached a record level of 7822.8Mt in 2013, increasing by 0.4% in comparison to the previous year.

        http://www.worldcoal.org/resources/coal-statistics/

        Having a most plausible worst case does not make other cases implausible, more so when implausibility is defined as being falsified, which may arguably be just another way to conceal incredulity arguments.

      • Hiya Steve, why do you say 4.5C? I would say the PDF trails to zero at 3.0C.

      • “Basically 8.5 is not plausible because U have to imagine that we lost the climate debate, when in fact we won it.”

        When does the meaningful mitigation start, Steven? Does it require any co-operation from the 7 billion folks who are not losing any sleep over AGW? You should be getting busy letting everybody know you won the debate, instead of monkeying around with some old mess of temperature data.

      • Steven Mosher

        Tom

        I am trying to stick to the definition of plausible.

        That is easier to do with emissions and mitigation assumptions in rcp 8.5
        that with sensitivity.

        in other words… I dont have any faith in the shape of PDFs about ecs.

        For scenario building I have no issue with rcp 6 emissions and a higher sensitivity.

        Understand the purpose of worse case.. worse case DOESNT have to drive your decisions about what to do.

        Worse case drives your uncertainty reduction activities and perhaps some disaster relief investment.

      • Steven Mosher

        “When does the meaningful mitigation start, Steven?”

        Already started. every little bit counts.

      • Steven Mosher

        willard

        ‘The death of coal might be a bit :”

        Note: dying is not death.

        coal is dying. just read any solar PV propaganda.

        not dead yet. dying.

        ‘ing” must have confused U

      • A little bit is not meaningful, Steven. You know that.

      • David Springer

        Coal speaking: “The report of my death was an exaggeration”

      • > coal is dying.

        This looks implausible, as the background knowledge is that coal provides around a third of global primary energy needs, generates over 40% of the world’s electricity, is used in the production of 70% of the world’s steel, and total world coal production reached a record level of in 2013.

        ***

        If coal is dying, then the claim:

        Humans will use 3,000 Quads by 2075. If they all come from coal we’re ruined.

        is implausible and could be interpreted as catastrophism.

        Cue to boy who cried wolf and ate cotton candy.

      • > coal is dying.

        This looks implausible, as the background knowledge is that coal provides around a third of global primary energy needs, generates over 40% of the world’s electricity, is used in the production of 70% of the world’s steel, and total world coal production reached a record level of in 2013.

      • If coal is dying, then the counterfactual

        If the 3k quads humans will use by 2075 come from coal we’re ruined.

        is implausible and could be interpreted as alarmist.

        Cue to boy who cried wolf and ate cotton candy.

      • If coal is dying, then the counterfactual

        [GWC] If the 3k quads humans will use by 2075 come from coal we’re ruined.

        is implausible and could be interpreted as alarmist.

      • Steven,

        For an analysis of the plausibility of the coal consumption assumptions in RCP8.5 see http://fabiusmaximus.com/2015/07/13/coal-climate-apocalypse-87192/

        White it is ambitious to say “coal is dead”, it is possible that coal use is peaking right now. That, of course, negates one of the core assumptions of RCP8.5: fantastic growth in coal use during the 21st C.

        We’ll have to wait for more data to assess assumptions of high population growth (at the high end of the current UN forecast), continued slowing of technological progress, and little success at mitigation.

    • “Providing arguments might have been better.”

      Why isn’t linking to them sufficient?

      • > Why isn’t linking to them sufficient?

        Because there’s none linked, and Blair’s argumentative storytelling is incredibilist in design.

        More on incredibilism:

        http://planet3.org/2012/08/24/incredibilism/

      • Steven Mosher

        I have to agree with willard.

        linking doesnt cut it. make the argument in your own words and cite the source for what it is. the source of your argument.

        otherwise we dont know what aspects of an argument you buy.

      • You do see that willard just linked to his argument rather than providing it, don’t you?

      • Steven Mosher

        Everything blair says is true.. just read the source document I linked to.

        rcp 8.5 is a joke. Like the fricking two front war assumption in defense planning. with one theatre in fulda gap and the other in NK.

        That was like a zero probability scenario.

        But ECS 4 or 4.5 isnt the same kind of joke.

      • Steven Mosher

        So?

        willard is imperfect. I still agree with him. linking doesnt cut it and NOW I point to willard as an example of how not to do it. simple.

      • ” Like the fricking two front war assumption in defense planning. with one theatre in fulda gap and the other in NK.”

        It wasn’t an assumption. Over your head and pay grade.

      • I have to disagree. At best you end up copying and pasting someone’s arguments, hopefully with quotation marks. At worst you try and paraphrase.

        The reason I don’t click on links is because some people I don’t trust have a habit of pretending the definitive answer is at the other end. What ends up happening is a chain of links that don’t provide the needed information.

        But if I trust the source I will click on a link. I don’t click on willard’s links because he is just playing games. But I would (and have) cheerfully clicked on links from JimD, for example.

        But I wish he would link to more kpop, I admit. In Shanghai, Korean TV series are all the thing. They’re almost as popular here in Taipei.

      • Steven Mosher

        Links

        https://www.youtube.com/watch?v=o6HFiVaK15I

        Tom in case you missed it.

        Remember Will?

      • > You do see that willard just linked to his argument […]

        Not at all. There’s no discussion of Blair’s argumentative storytelling under that link, only a description of incredibilism.

        Besides, which part of “because there’s none linked” you do not get?

      • > rcp 8.5 is a joke.

        More precisely, it’s based on this storyline:

        The scenario’s storyline describes a heterogeneous world with continuously increasing global population, resulting in a global population of 12 billion by 2100. Per capita income growth is slow and both internationally as well as regionally there is only little convergence
        between high and low income countries. Global GDP reaches around 250 trillion US2005$ in 2100. The slow economic development also implies little progress in terms of efficiency. Combined with the high population growth, this leads to high energy demands. Still, international trade in energy and technology is limited and overall rates of technological
        progress is modest. The inherent emphasis on greater self-sufficiency of individual countries and regions assumed in the scenario implies a reliance on domestically available resources. Resource availability is not necessarily a constraint but easily accessible conventional oil and gas become relatively scarce in comparison to more difficult to harvest
        unconventional fuels like tar sands or oil shale. Given the overall slow rate of technological improvements in low-carbon technologies, the future energy system moves toward coal-intensive technology choices with high GHG emissions. Environmental concerns in the A2 world are locally strong, especially in high and medium income regions. Food security is
        also a major concern, especially in low-income regions and agricultural productivity increases to feed a steadily increasing population

        http://link.springer.com/article/10.1007%2Fs10584-011-0149-y

        Further details are given in Riahi et al. 2007. Considering the laissez-faire policies Denizens are trying to sell on this thread, this “relatively conservative business as usual” scenario may not be that implausible.

        ***

        Interestingly, RCP 8.5 does not exclude air quality legislation:

        RCP8.5 assumes the successful implementation of present and planned environmental legislation over the next two decades to 2030. Beyond 2030 we further assume that increasing affluence may lead to tightening of pollutant legislation in the long term (see also Section 2.3.1).

        An assumption that has interestingly not been mentioned:

        Note that the mitigation scenarios assume full “when and where” flexibility to reduce emissions, subject to a global cumulative GHG emissions constraint for each radiative forcing level. Different measures are thus deployed based on endogenous model decisions to derive a least-cost solution.

        This assumption might arguably be implausible. This implausibility does not argue in favor of a less conservative scenario.

      • Steven Mosher

        Tom put a kpop 360 video on your phone.

  17. > Nic Lewis’ research arguably falsifies the high values of climate sensitivity determined from instrumental data, owing to problems with the statistical methodology and the forcing data.

    That’s not in Betz’ text. Italics are lingering.

    The connection between this conclusion and Betz’ definition is not that clear, BTW.

    • Steven Mosher

      ya.. I see this decision by Judith as being somewhat arbitrary.

      Paleo estimates of 3C +-1.5 are not implausible.

      the difficulties in estimating ECS are sufficient to justify looking at the
      highest plausible number of the various methods as your worst case number.

      • > the difficulties in estimating ECS are sufficient to justify looking at the
        highest plausible number of the various methods as your worst case number.

        That’s a joke, right?

      • “Paleo estimates of 3C +-1.5 are not implausible.”

        In your opinion perhaps. In others (most?) opinions the paleo estimates become far less plausible after reviewing the instrumental data

      • Steven Mosher

        Willar U want to argue that 4.5 is implausible.. go ahead.

        I look at three methods. with no clear way to decide between them.
        I’m going to draw my worst case accordingly

      • davideisenstadt

        so an estimate of 5C+/-3.5 would lead you to conclude just what?

      • “so an estimate of 5C+/-3.5 would lead you to conclude just what?”

        That the person making the estimate is an alarmist making an unrealistic assessment

      • > U want to argue that 4.5 is implausible.. go ahead.

        I’d rather argue that the highest plausible number may not be the worst case number.

      • Paleo estimates are for a completely different forcing mechanism and are fudged because they don’t treat albedo changes as a feedback. If they did, ECS would be 40C because the actual forcing is negligible.

      • Willard, “I’d rather argue that the highest plausible number may not be the worst case number.”

        True, the worst case for some might be the range from 0 to 1 C after they buy their retirement villas in Greenland. Hansen has mentioned oceans boiling on occasion and Pierrehumbert is a bit fond of the Planet of the Apes image of the Statue of Liberty buried in the sand.

        https://thingsthatmadeanimpression.files.wordpress.com/2012/07/picture-planetoftheapes_hell2.jpg

        I believe the Planet of the Apes was a nuclear holocaust case though. Risk assessment based on science fiction.

      • Paleo estimates of 3C +-1.5 are not implausible.

        Gee.

        The original 1.5-4.5 was from a 1979 conference where a reasonable model (2°C) and the Hansen model (4°C) were combined with a 0.5°C slop factor to give a 1.5-4.5°C range for ECS.

        There is nothing scientific about it. They didn’t go out and measure anything. They just guessed. Confirmation bias (and the desire for another round of funding) pretty much guarantees that paleo studies will support something in the guess range. Given that people actually claim that the PETM – where temperature led the CO2 increase by 5K years – supports global warming, it is pretty clear that people are reading whatever they want into the paleo studies.

        The February 2015 study said 0.2 W/m2 for 22 PPM or 2.4 W/m2 TSR with two very diverse measurement locations.. That implies a 3.6 W/m2 ECS or about 1°C.

        Short of a different study with differing data at multiple locations the ECS is 1°C.

        Paleo guessing produced the hockey stick and should not be used as a substitute for real world empirical measurement.

        If it isn’t important enough to measure precisely, if guessing is good enough, the problem isn’t worth worrying about. For over 35 years CAGW fell into the “not worth worrying about” class.

        Given the February 2015 study which infers a downwelling IR change equivalent to 1.05 W/m2 since 1900, it still isn’t worth worrying about.

  18. Curious George

    The worst scenario for climate change has nothing to do with science – we don’t know enough yet. Putting more CO2 in the atmosphere may or may not be a good idea. However, the alternative is a guaranteed poverty. I see that as the worst scenario.

    • What percentage of the world currently lives in poverty?

      • That depends on who gets to make the judgement call.

      • What percentage of the world currently lives in poverty?
        ====================================
        There are more wealthy people living on the planet today that all the wealthy people in history added together.

        By current standards, almost everyone living 200 years ago was living in poverty. By current standard you are very likely living a better life than kings and queens only a few hundred years ago.

      • Hilarious.

      • David Springer

        Most of us don’t live better than kings and queens from 200 or more years ago. Get serious. Some had seriously hedonistic lives of leisure that the vast majority cannot afford today. Wine, women, and song have been around a very long time and were as good then as now. Lifespans of royalty have never been particularly short either. Good genetics, no stress, always warm and well fed.

  19. “falsification of these scenarios could be accomplished by comparing modeled and observed warming for the period since 1950, and assessing whether the equilibrium climate sensitivity for that model is too high (with a value of aerosol indirect effect that is far too high)”

    Comforting as it is that observed warming is lower than the models, that does not mean that the “A” part of AGW is not as large a magnitude as the models predict. It could be some natural cooling going on, that no one knows about. I don’t think this falsifies.

    A Falsification would require proof that some part of the AGW modelling is wrong. A negative feedback cycle from clouds would be one. Proof Aerosol contribution to cooling was overstated. Etc.

    • A Falsification would require proof that some part of the AGW modelling is wrong.

      The model output has not matched real data for two decades. That is more than enough proof. When model output does not match real data, it is the models and the theory the models are based on that is wrong. There is no real proof that any of the AGW modelling has anything correct. How do you prove that something that is always wrong is really right?

      The part that is wrong is the part where AGW models prove that earth is getting warmer, out of bounds while Mother Earth Data shows earth is still inside the bounds of the past ten thousand years. There is no part of AGW modeling that has been proved to be right.

    • if the model output is wrong, that does not prove the models are wrong, how wrong is that !!!!! ? Natural warming and cooling has gone on forever and there is no proof that natural cycles stopped and that AGW warming and cooling did replace natural cycles.

      • That’s not what I said. Obviously the models are wrong, but you don’t know if it’s the Anthro part of the global warming or some other part. You can’t know until you map out all man made and natural contributions to global warming. You can never know if you have mapped out all contributions to global warming. That’s why this approach is not “Falsification.”

    • A Falsification would require proof that some part of the AGW modelling is wrong.
      =================
      you are mistaking correction after the fact with prediction and falsification.

      science makes predictions. otherwise it has no value. end of story. if those predictions are wrong, the theory is wrong. also end of story.

      after the fact there are an infinite number of reasons that will present themselves as to why the theory was wrong. once of those reasons may be correct, but that is not science.

      it is superstition, because in an infinite universe there are ALWAYS explanations after the fact. These explanations tell us nothing, except that the theory was wrong, and that in an infinite universe there are infinite excuses for the past. end of story.

    • edbarbar:

      Obviously the models are wrong, but you don’t know if it’s the Anthro part of the global warming or some other part.

      If the models cannot be falsified can they legitimately falsify contrary interpretations?
      For example, we are living in an interglacial period. Evidence exists that past climates were warmer than current conditions so it is not possible to disprove the assertion that ALL recent warming is natural.

      Under the circumstances, perhaps we should stop criticizing policymakers who believe that humans cannot change the climate. Or at least wait until we have better models?

      • Under the circumstances, perhaps we should stop criticizing policymakers who believe that humans cannot change the climate. Or at least wait until we have better models?

        I’m not a big fan of the models for many reasons. For the same reason you can’t falsify the anthro part of the models by comparing to actual temperatures, you only guess at how good the models are. I’m a fan of measuring and analyzing. I think that will yield much better future estimates of AGW than models.

        I merely don’t think you can disprove the “A” part of AGW with this method.

  20. I think the biggest risk is a failure to appreciate the fact that no matter what we do the climate will change.

  21. The first question is what is the emissions curve going to look like.

    https://yearbook.enerdata.net/CO2-emissions-data-from-fuel-combustion.html

    http://nea-polis.net/wp-content/uploads/2014/10/World-Fuel-Consumption-and-Population-1900-2050-1024×756.jpg

    Note the fuel consumption from NEA is MTOE not carbon. According to Enerdata the globe emitted less CO2 in 2014 than 2013.

    The NEA curve is a prediction of a peak of about 13.8 GT emissions in about 2038. Given they didn’t anticipate the 2014 decline they are already pessimistic.

  22. daveandrews723

    James Hansen has gone off the “deep end” and he is considered one of the top handful of climate scientists??? There’s your problem right there… they have all worked themselves up into a frenzy, plus they enjoy their improved incomes that come with sounding the alarms and beating the drums.

  23. Dr. Curry — Regarding you statements on Nic Lewis and It is becoming increasingly difficult to defend values of ECS that exceed 3.5C

    For us lay people, is there an IPCC Scenario that “approximates”, or “comes closest to”, or “conceptually reflects” your 3.5C belief?

    Thank you.

  24. That means we should concentrate especially on understanding what is the worst that could happen, and how likely that might be.

    The worst that could happen, of the worst things that have been forecast, is really awful, but those things have not happened in ten thousand years and are are really not likely to happen in the next ten thousand years.

    We should concentrate on things that are really likely to happen and not on things that are so extremely unlikely to happen..

  25. The worst case scenario is that at one of these Climate pow-wows the world’s nations decide to install mandatory CO2 controls and then follow them. MIllions die of cold and starvation. Many millions continue to live in pre-industrial conditions. Billions suffer from deprivations of many modern conveniences and from the ravages of war due to the inevitable conflicts when cheaters are confronted.

    But I guess a few thousand zealots would feel better about themselves.

  26. “worst scenario’ for climate change?”

    A protracted solar minimum with the associated droughts and cold episodes.

  27. What the heck am I missing? Why would you plan for worst case? You cannot and never will get anywhere in life with that sort of plan. You are planning to fail before you start.

    The best plan is to go with “most likely” if you are reasonably well off to start with. If you are behind the 8-ball then your only choice is to try unlikely but high reward.

    The current plan, of worst case with high cost is the lunatic solution. You’d have to be nuts to try it.

    • +++++++++++++++++++

    • Steven Mosher

      Its typical to do worst case planning.
      defense planning is driven by a worst case.

      As an excercise You want to plan for the worst plausible case.

      I keep 3 days of food and crap for a Sf earthquake.

      • I would think that the three days of food you keep will solve the crap problem–why would you lay that in?

        After the 89 earthquake when the power was out and the bridge was down I went to the same Chinese eatery for every meal. But I didn’t eat any meat or seafood, as the air con was out.

        I still think they should have left the flag on the Ferry Building at a tilt as a memorial.

      • David Springer

        I thought you said you were no longer in SF, Mosher.

      • Steven Mosher

        Wrong Springer.
        when I posted the comment I wasnt in SF.
        Now I am.
        Travel… imagine that.

      • davideisenstadt

        geez mosh.

      • Travel… imagine that.

        I hope you didn’t spew any DAMN CO2 IN MY ATMOSPHERE to get there!

        Or maybe that’s OK. My pecan trees will gladly turn it into pecans.

      • David Springer

        I don’t travel much out of concern for how much CO2 I’m emitting.

        Imagine that. ;-)

      • David Springer

        Sorry to have misinterpreted your remark.

        I don’t travel much out of concern for how much CO2 I’m emitting. Imagine that. ;-)

        I assume that very concerned others such as yourself are not hypocrits and practice what they preach. Mibad. A character flaw of mine is always assuming the best in others. In your case I definitely should have known better.

    • Except there was no net damage

      • There is some damage to the pause, but maybe the pausists have moved on already and the pause is dead to them.

      • No damage to the pause. It never was a pause. It remains a crawl. The worst scenario assessment presumes we can understand the crawl. Unfortunately, the crawl negates all we thought we knew.

    • Slightly warmer is not bad. You can’t point out where the climate is worse

    • Most of us who have commented on the hiatus have been clear that we expected warming to resume. The pace of the resumption is of interest of me, as I have bet Joe Romm $1,000 that this decade’s warming will be modest.

      You wouldn’t be silently thanking the El Nino gods that they showed up in time to bail you out, would you?

    • Does Obama and his peeps know about all this Hottest Evah hysteria? If they are worried, surley they would be doing more than they are doing. EPA Administrator at July 9, Congressional hearing:

      CHAIRMAN LAMAR SMITH: “On the Clean Power Plan, former Obama Administration Assistant Secretary Charles McConnell said at best it will reduce global temperature by only one one-hundredth of a degree Celsius. At the same time it’s going to increase the cost of electricity. That’s going to hurt the lowest income Americans the most. How do you justify such an expensive, burdensome, onerous rule that’s really not going to do much good and isn’t this all pain and no gain.

      ADMINISTRATOR GINA MCCARTHY: “No sir, I don’t agree with you. If you look at the RIA we did, the Regulatory Impact Analysis you would see it’s enormously beneficial.

      CHAIRMAN SMITH: “Do you consider one one-hundredth of a degree to be enormously beneficial?”

      ADMINISTRATOR MCCARTHY: “The value of this rule is not measured in that way. It is measured in showing strong domestic action which can actually trigger global action to address what’s a necessary action to protect…”

      CHAIRMAN SMITH: “Do you disagree with my one one-hundredth of a degree figure? Do you disagree with the one one-hundredth of a degree?”

      ADMINISTRATOR MCCARTHY: “I’m not disagreeing that this action in and of itself will not make all the difference we need to address climate action, but what I’m saying is that if we don’t take action domestically we will never get started and we’ll never…”

      CHAIRMAN SMITH: “But if you are looking at the results, the results can’t justify the cost and the burden that you’re imposing on the American people in my judgement.”
      Read more at http://www.liveleak.com/view?i=559_1437054944#svw8h58aw6YgK6CY.99

      So yimmy, U. S. leadership in saving the planet from AGW amounts to implementing policies that will with hope and change and fingers crossed reduce potential warming by one one-hundredth of a degree.

      Fanfreakingtastic! If all the other major CO2 producers follow our bold lead, how much hellish heat will be prevented, yimmy? Surely the thug bosses in Red China can force their people to do two or three one-hundreds of degree. The Indians might not be able to manage the one one-hundredth. That’s OK, they poor folk. Anyways, how much are we up to now, yimmy? Please do the math for us.

      • The math is that if we keep emitting at the current per capita rate, you get to about 700 ppm around 2100. That’s 4 C(!), not a hundredth. These are the temperatures the rest of the world outside Congress are talking about. They live in a coccoon.

      • Don Monfort

        You need to learn how to read, yimmy. The EPA Admin cannot disagree that the Obama decreed measures will only reduce da heat by one one-hundredth of a degree. How does that get the ball rolling for meaningful global mitigation, yimmy? Try to be honest and realistic for once, yimmy.

      • Don Monfort

        Come on yimmy, show us what you got. You say that Congress is in a cocoon, but the difference in what they are willing to do about CO2 mitigation and what the Obama regime has produced in six years in power is one one hundredth of a degree. If I were a little greenie Chicken Little fearing 4C (!) by 2100, I would be apoplectic over this Obama crap. He said he was going to take care of this existential problem, back in 2007. WTF is he doing to you, yimmy?

      • While the EPA can’t control the world’s emissions, if the world followed Obama’s goals for decarbonization by 80% by 2050, they would keep CO2 levels near 450 ppm, which would meet the goals for global emissions. While their 0.01 C number looks like it is low by a factor of at least ten (they really need to show their work), it is not the number you need when you put this policy on a global scale where it becomes more like 2 C.

      • Donnie: The US of A has a moral responsibility to be the beacon of righteousness in all aspects, not just military might, banking usury, and sweatshops. My god, as long as we can keep McDonalds, Starbucks and Costco, quit yer whinging.

  28. Pingback: Hansen’s Catastrophic Vision of Climate Change This Century | The Lukewarmer's Way

  29. A worst case scenario for disaster can come in many different forms that are as destructive or possibly worse than the worst case plausible scenario for climate. A myopic focus on climate channels too much prescious resource into mitigation for an event that may, or may not happen. And if it does happen the effects could be of little consequence. It’s also possible AGW can have a net positive effect; i.e. It could mitigate severe cold brought on from solar conditions.

    Which one would you prioritize as being the most plausible? 1) stress from debt leading to depression 2) systemic collapse of global economies 3) world war escalating from Islamic fundamentalism; or from unstable governments on the verge of collapse taking what they need leading to escalation 4) mega natural disasters other than climate (multiple choice selection). 5) GW.

    Is there any one thing that could serve as, if not a solution, then a best case deterrent, mitigation source acting as a cushion to lessen hardship? I would say yes, a strong economy. Depending on the crises, a strong economy allows more resources to be expedited and channeled directly into R&D (alternatives et al); it allows for better protection and/or projection where necessary and when necessary. It acts as a basis for robust foreign aid. Without a strong economy then mitigation of any event becomes fractional, muted.

    In the U.S. today; there’s a new low, more small businesses going bankrupt then new ones being created. This is the backbone of jobs. The borders are virtually non existent. If sleeper terrorist cells wanted to infiltrate the border they can at any time. Illegal immigration not only soaks up low skill jobs, but they’re a substantial strain on social services. Debt continues to soar. If interest rates reach the historical mean, 5% range, every dollar the government brings in would go to pay interest on the debt. Unemployment: the U.S. has a 62% job participation rate, much of the job creation is part-time and/or low skill. Over 15% of the job force is public sector, of those few are part-time. The average wage in the public sector has continued to outpace the private sector since 1980. The welfare role is near 50 million.

    What is the risk; of proposed AGW punitive actions towards disabling a robust call to action for R&D for alternatives when considering the state of the economy? Between a strong private sector rallying in synergistic fashion with government sponsored research?

    I believe a strong economy must come first; it’s the engine for everything else. Being the least mangy dog in the global economic kennel is of little help to anyone. Shifting money around is not a solution. Squeezing industry to eliminate CO2 without stimulating growth, is not a solution. A strong economy, is a solution. We don’t have a strong economy. It’s not getting better, it’s on a credit card.

    • My argument for many years too: a strong economy is the best preparation for whatever, and we don’t know what the “whatever” will be. Faustino

    • Jungle

      “Being the least mangy dog in the global economic kennel is of little help to anyone. ”

      LOL! Did you trademark that? :) I can’t wait for my first opportunity to use that one.

      Btw, yor post is spot on. I think the USA is getting “Greeked” ™. Rising public debt, under funded public pensions at the local level, slow economic growth, low labor partcipation rate, massive migration from poor broken nations, election of populist demagogues…we got it all baby…

  30. The words “pause” and “hiatus” presume that warming will resume. The question is when? It could be after the much hyped upcoming el nono; it could equally be a couple hundred thousand years hence after the next glacial stage. In neither case would we have even the first clue why it happened. What the crawl unquestionably shows is that whatever forcing we self aggrandizingly attribute to our Carbon liberation is at very least nearly equaled by a countervailing natural force. Of course, it also remains possible that ALL of the warming is natural and we are simply delusional.

    • If they were equal, it would cool. It hasn’t come remotely close to cooling since 1940 to 1952.

      • If you want to go micro, ok, there was a “hiatis” in about the middle the 1945 to 76 cooling trend. It cooled very rapidly from 1969 to 1976. That was when Mr. Watt proclaimed at the first Earth Day at UC Davis in 1970, “At the present rate of nitrogen build-up, it’s only a matter of time before light will be filtered out of the atmosphere and none of our land will be usable.”

  31. You were correct in identifying the word “plausible” as an issue in this type of analysis. However, “possible” may not be correct either. The phrase we always used in doing strategic analyses was “reasonable worst case scenario”. For example, a 100′ rise in sea level might be possible by the turn of the century, a 20′ rise is plausible, but a 1′ or 2′ rise might be reasonable.

  32. Impact Sources:
    Energy, transport, industry, food production, forestry and general landuse changes.
    Known Impacts:
    Air pollution, water pollution, habitat destruction.
    Potential Impacts:
    Sea level, drought, flood, heat.
    Prioritize Mitigation
    Known Impacts using existing tech
    Unknown Impacts using adaptation, low-hanging fruit, reduce impact uncertainty
    Recommended Actions:
    Kill coal with CH4, increase nuclear power, electric cars, increase industrial air pollution controls, increase pollution prevention, reduce monoculture, reduce over fertilization, reduce pesticide use, increase ground and surface water storage, runoff control, erosion control, sustainable forestry, sea walls, air conditioning

  33. In the real world plausible equals actionable.

  34. First comments: the CCARA authors seem to make assumptions which are contestable, e.g.: “Climate change fits the definition of a risk because it is likely to affect human interests in a negative way;” current and expected policies will keep emissions “on a moderate trajectory, still far in excess of what is required to limit the impacts of climate change below a harmful level.” These possible impacts are part of the unknowns, there may be net benefits from a warmer Earth.

    Judith says that “The appropriate focus is the plausible worst case scenario.” I disagree that policy should be driven by the worst plausible warming scenario. What about the worst plausible scenarios for nuclear war, epidemics, asteroid strikes etc, etc? We could easily devote all resources to futile attempts to deal with scenarios which might, and probably will, never eventuate. And what about offsetting them with “best plausible scenarios,” e.g. through cheap energy breakthroughs, genetically modified crops etc? At the risk of being boring, I repeat that we should adopt policies which give us the capacity to deal well with whatever future eventuates.

    Faustino

    • ++++++++++++++++++++++++++++++++

      • Can’t argue with that, beth!

      • He still needs a few hundred more runs.

      • Cruel mosomoso.

      • 405 actually! :)

      • Cricket, lovely cricket … I grew up in a poor, fatherless family. Shortly before my 11th birthday, I came top of the “11-plus” exam for Grammar School entry, out of over 2000 entrants. As a birthday/exam present, my mother said she’d buy me a cricket bat – a rare treat. It had to be from somewhere she could get credit. That left me with a choice of two bats – a size six, which didn’t feel right, or a size seven. I didn’t know that adult professionals used size six. I went for the seven, it felt better and I thought it would be good for the long term.

        However … that great chunk of wood led me to have a very limited batting style. I opened the batting for my school: I couldn’t score quickly, but that big bat was hard to beat, it was hard to dismiss me.

        So … I’m thinking that the England batsmen should be issued with over-size bats for the rest of the series, so they’ll be presenting a large face and won’t be able to flash cavalierly at balls off the stumps. They could frustrate and grind down the Aussie bowlers, switching to a smaller bat when the ball is old and the bowlers are tiring. Sound like a plan?

      • Nope. Not a plan. Looks like it’s kiss-and-make-up with Kevin Pietersen. Brrr.

      • Faustino, I’m afraid, very afraid, that your mob has lost the plan altogether and its Bye Bye ashes. That was a complete rout at Lords and all confidence has been lost for the next tests to come!

      • Please take the incomprehensible cricket discussion to the bickering thread.

    • Well, Peter, I have to agree, my expectations were very low, Cardiff was a welcome respite, back to normal, I fear. I recall that when England regained the Ashes, UK commentators were talking about a 10-15 year ascendancy. I rolled my eyes.

      Anyway, my cricket-loving Aussie wife has had a few chortles in recent days.

      • Faustino

        I am pleased to report that my robust model using the latest homogenised and smoothed data illustrated that England won by 267 runs.

        You shouldn’t listen to those people,who are obviously biased as to the outcome they want and who can only rely on facts and observation and not trust models.

        Are they anti science? You can judge.

        tonyb

      • “Well, Kevin…I mean, Mr Pietersen…we’ve had our differences in the past, old chap, but…”

    • Faustino,
      You should keep repeating your last sentence. Better still, keep reiterating comments like you made in you recent, excellent letter you sent to the Australian.

    • David Springer

      Plausible best case.

      No balance in this debate. Curry styles herself as objective and surely understands there are known benefits to CO2 enrichment as well as huge benefits of cheap energy. There are also uncertain potential benefits like arable land and longer growing seasons marching north and south towards the poles, greater drought tolerance for primary producers in the food chain, less worry about unexpected killer frosts, and so forth.

      The plausible best case is a proverbial bowl of cherries!

  35. The alleged CAGW scenario has been replete with doomsday warnings and rushed responses – drastic and costly action has preceded knowledge and understanding. There is an alternative.

    In 1974, a war game was held at the Royal Military Academy Sandhurst to assess the outcome if Germany’s proposed 1940 invasion of England, Operation Sea Lion, had been implemented. Many of those taking part were in command on either side in 1940, and would have been making decisions then. The war game was later written up in the form of a novel.

    Early in the assault, an officer at a cliff-top observation post north of Dover was observing the German landings. It was clear that Dover would soon be over-run, and para-troops were landing inland. The second observer, a sergeant, sought to attract the officer’s attention. The officer, aware that they would soon be behind enemy lines, thought that the sergeant was seeking permission to scarper, and told him he could leave.

    The sergeant replied, “It’s not that, sir. It looks as if things might be pretty unsettled from now on. Could I put the kettle on?”

    This is the British genius. In the face of a stressful and uncertain situation, don’t react hastily. Stop, have a cup of tea, gather your thoughts; then act from a calm space, rather than react with the adrenaline of the moment.

    Imagine if, back in the Rio Conference in 1992, some Brit had said, “Now, steady on, chaps, let’s have a nice cup of tea and think this thing through.” How much trouble and angst might have been saved!

    So, when someone comes to you with a “plausible worst scenario,” just say “Well, it might be plausible, but will it happen? Let’s have a cuppa and not rush into the unknown.”

    Faustino

  36. I would love to see a piece on how “worst scenarios” and the precautionary principle would work if it were widely adopted as is proposed by some for climate. Certainty there are worst case risks of San Francisco, LA and Seattle having huge death tolls from earthquakes. How does the cost benefit ration of moving people inland to mitigate that risk compare to reducing C02? New York could get a worse case hurricane (Well beyond Sandy). How would mitigating that by moving the population to Iowa compare to what is proposed on Climate.

    Maybe the precautionary principle as compared to climate makes more sense, but an exercise explaining why (AND SOME ORDER OF MAGNITUDE AS TO WHY) would be helpful.

    • bedeverethewise

      Given the proposed relocation plan, the citizens of Iowa are pretty sure no hurricane will ever hit New York.

    • At the very least we should end the “subsidies” of all west coast residents- who are, after all, just deniers of the basic physics of earthquakes.
      End federal funding of all west coast states and municipalities for roads, airports, schools. End all income tax deductions for residents. By 2020 end all social security, medicare, medicaid and food stamp federal funding to residents of those states.
      By 2025 eliminate the US Senate and US House seats apportioned to California, Oregon and Washington.
      Because we know tax incentives encourage “action!’ gradually increase income taxes on all remaining residents of those states to 100% of income by 2030. All proceeds to go to relocation costs.
      The precautionary principle demands this if it saves just one life and the big one is far more plausible than global warming at this point. The destruction of these states doesn’t just impact the residents- the cost (in both money and lives) of rescue operations and reconstruction would be astronomical. To be sure, there are some who will argue that the cost of abandoning California, Oregon and Washington would be too great and the timing of an earthquake is uncertain, but there are always merchants of doubt and the time for debate is over. Abandoning these states would be cheap, easy, and necessary and we merely lack the political will to make it happen.
      I recommend legislation this year, we can call it the COLN act of 2015 (Creation of Libertarian Nirvana)

      • Think of the children,

      • Rewilding North America
        The idea of ‘rewilding’ was developed in the mid-1900’s by Michael Soulè. According to Soulè rewilding means restoring large native predators into the wild. However, rewilding has been expanded to include megafauna.
        http://rewildingnorthamerica.weebly.com/

        Michael E. Soulé is a U.S. biologist, best known for his work in promoting the idea of conservation biology. He earned a Ph.D. in Population Biology at Stanford University under Paul R. Ehrlich.
        https://en.wikipedia.org/wiki/Michael_E._Soul%C3%A9

        Rewilding California sounds like a great idea!!!
        Why stop with Pleistocene Rewilding?
        We could go Jurassic!!
        https://en.wikipedia.org/wiki/Jurassic_Park

      • People always have a right to risk their own lives, but when it comes to risking other people’s lives there is a difference in what precaution means.

      • Jim D. I’m working on that distinction it has some appeal and maybe it’s a good one but maybe not. It may work for climate versus earthquakes or hurricanes, but maybe not so much for examples like curtailing travel (with unless accompanied by long quarantines in isolation) to stop potential pandemics. (But maybe you’d get behind that). Do we put all the money we can into technology for blowing up potential asteroids which collectively might doom us. How much freedom are we willing to give up to save individuals from potential deadly semi random attacks (worthy question with many credible answers/views but the debate is not aided by the precautionary principle).

        The response of choosing for yourself may be a little glib. Why use such disparate risk acceptance from what overwhelmingly people choose for themselves for dealing withcollective risk. We don’t care about others risks from but potentially catastrophic events. People are “compelled” to go to earthquake zones all the time as part of normal expected business travel. Can people choose potential catastrophic risks for their children? Other people’s children? Is it ok to incarcerate people in these areas? Can any of us really be assured ever that our actions won’t ever contribute somehow to an increased by very small risk of catastrophic harm to others? Can’t we all (from any political leaning) point to others whose life “choices” subject us to remote but potential risks in some theoretically possible way? Do we worry about all risks to others?

      • @Jim D | July 21, 2015 at 11:49 pm |
        “but when it comes to risking other people’s lives there is a difference in what precaution means.”
        However, you have to PROVE, not ASSERT, that the use of fossil fuels is putting you at risk. You have not done that, so you have no basis to limit my freedoms.

      • jeffn,

        I went through the 89 quake here in CA. Some people did not have quake insurance and suffered losses. The state of CA, reacting in typical clueless form, mandated that all companies selling home insurance in CA offer earthquake insurance. Predictably, many companies left the state – they don’t sell homeowner insurance in CA anymore. Now, when you go to buy fire insurance, the company – to protect themselves, they aren’t politicians, they are not dumb, they hire mathematicians – wants to verify that your home is earthquake safe. Some companies will not sell fire insurance in certain neighborhoods because the terrain is considered risky for earthquakes – they want engineered foundations. Not many homes built before 1989 have “engineered” foundations. If the homeowner wants to assume the risk of an earthquake but transfer the risk of fire, they cannot. Ironically, retrofitting an old house to handle an earthquake is not so hard – the labor and materials, many invented or improved after the quake (the market and technology sector response to demand), is readily available. However, the damage to the insurance industry appears permanent. Insurance is either expensive ( very high deductibles and premiums) or unavailable, all due to an incompetent government response. Those unintended consequences are really a britch. Sorry about the stilted language and typos – typing on an iPad is painful.

      • I’m referring to the big one- the one recently in the news that would literally destroy large swaths of the west coast.
        To JimD’s point, lives will be lost attempting to rescue the earthquake deniers (just as lives are lost fighting fires there), thousands outside of those states will be economically ruined by the destruction, all of us will have to pay for it all. And, finally, how does a child get to decide how to risk their lives? Would you amend my modest proposal (sorry Swift) to simply prohibit from those states: children, the mentally ill, any person who has not passed a test proving knowledge of the risks?
        Why not use a “price signal” to “mitigate” damage and encourage “conservation” of life by prompting people to “take action” and move out of those states? Why subsidize their dangerous lifestyle with mortgage tax breaks and income support for the indigent? And we can safely assume from your points that you don’t believe the state has any business getting involved in cigarette smoking- people have a right to risk their own lives and all.
        Justin, I live five miles from the Atlantic ocean where hurricanes are a fact of life. I feel your pain re insurance!

      • Don Monfort

        You are wasting your time here, yimmy. These folks are not buying your story. They don’t want to do anything about CO2, until somebody provides convincing evidence that it is necessary.

        Anyway, as Mosher says, they don’t have the power to do anything. You need to work on your hero king of hope and change Obama, who in six years on this jacked-up throne has only managed to impose costly regulations that will forestall the pathetically inconsequential amount of one one hundredth of a freaking degree of alleged warming from ACO2. Chain yourself to the Whitehouse fence and harangue your inept king for a while, yimmy.

      • Jeffn.

        I agree with you regarding price signals. People can decide what they are willing to pay for. My problem is with counter-productive government policies that distort the market. In this case it is a state regulation. Every place has it’s own set of risks – flooding, fire, earthquakes, tornados, hurricanes, mudslides, avalanches …

        People that live below a dam are least likely to worry about a dam failure. I think this form of you know what allows people to get on with life in the NW. After all, for the first 99 days the life of a turkey is pretty good. :)

    • During certain regimes storm tracks tend to take the Sandy route more often and I think NYC is long over due for a cat-5 hurricane. Hopefully it happens during low tide.

      • Sandy wasn’t even a hurricane at landfall. NYC needs to bite the bullet and FUND ITSELF to beef up infrastructure. It is highly likely a real hurricane will come along at some point in time. From the article:

        In a technical report released on Tuesday, the National Oceanic and Atmospheric Administration (NOAA) reaffirmed its initial conclusion that Hurricane Sandy was no longer officially a hurricane when it made landfall on Oct. 29 near Brigantine, N.J., just north of Atlantic City. Instead, it was a “post-tropical cyclone” packing hurricane-force winds, the report said.

        However, it also said that hurricane-force winds reached the New York coastline while the storm was still a hurricane, and that storm surge fatalities may have occurred while Sandy was officially a hurricane as well, raising additional questions about why no hurricane warnings were issued for any locations north of North Carolina.

        http://www.climatecentral.org/news/nws-confirms-sandy-was-not-a-hurricane-at-landfall-15589

      • Yes, preparing for storm surge in NYC, whatever the cause, is preparing for weather of the past. I understand that much of Manhattan, in particular, is sitting on very high groundwater. The pumps are busy.

  37. BorealForest#!$

    @Edbarbar …
    ” Falsification would require proof that some part of the AGW modelling is wrong.”

    I think this puts carts and horses in reverse order. It’s the models that need to demonstrate they are interpreting reality (measurement) correctly since they stand outside of reality already … they exist in computers not the real world. Reasonably consistent measurement indicating that the models are too hot requires that the modellers prove that their models are correct but reality is being affected by some compensating mechanism.

    The requirement that others prove some part of the AGW modelling is wrong is the same as saying any model result is correct … unless someone can find the funding to find a real world physical source for the error in the model … an impossibly high standard, and backwards.

    Reality should trump any model unless the >>modeller<>wrong<>correct<<, but in for the past 18 years the increase in forest cover has skewed real world measurements. We'll get back to you when we have a better results."

    Both statements test the model against reality. This kind of statement leads to gradually improved models until they become plausible for use in policy making.

    ======================

    @edbarbar | July 21, 2015 at 5:09 am |
    "That’s not what I said. Obviously the models are wrong, but you don’t know if it’s the Anthro part of the global warming or some other part. You can’t know until you map out all man made and natural contributions to global warming. You can never know if you have mapped out all contributions to global warming. That’s why this approach is not “Falsification.”"

    IMO we should assume the models are false until they become plausible — not exactly correct and a "true" interpretation of reality, but plausible for the purposes of policy making while being constantly tested against real world measurements. The first step is to get the models to mimic the real world. The second step is to tease out man-made vs natural contribution ratios.

    We are a long long way from knowing the models are not false. In the mean time the modellers have significant work to do and I believe that in the background, far from the headlines, they are most likely doing that work as best they or anyone can.

  38. Well! That messed up pretty good! Here’s better formatted comment where the example statements should come through properly.
    ===================
    BorealForest#!$

    @Edbarbar …
    ” Falsification would require proof that some part of the AGW modelling is wrong.”

    I think this puts carts and horses in reverse order. It’s the models that need to demonstrate they are interpreting reality (measurement) correctly since they stand outside of reality already … they exist in computers not the real world. Reasonably consistent measurement indicating that the models are too hot requires that the modellers prove that their models are correct but reality is being affected by some compensating mechanism.

    The requirement that others prove some part of the AGW modelling is wrong is the same as saying any model result is correct … unless someone can find the funding to find a real world physical source for the error in the model … an impossibly high standard, and backwards.

    Reality should trump any model unless the –modeller– can explain why the model is wrong or correct. For example

    “The model is –correct–, but in for the past 18 years the increase the increase in forest cover has skewed real world measurements. We’ll get back to you when we have a better results.”

    Or

    “The model is –wrong–. We now know we need to know more about cloud albedo and energy transport.”

    Both statements test the model against reality. This kind of statement leads to gradually improved models until they become plausible for use in policy making.

    ======================

    @edbarbar | July 21, 2015 at 5:09 am |
    “That’s not what I said. Obviously the models are wrong, but you don’t know if it’s the Anthro part of the global warming or some other part. You can’t know until you map out all man made and natural contributions to global warming. You can never know if you have mapped out all contributions to global warming. That’s why this approach is not “Falsification.””

    IMO we should assume the models are false until they become plausible — not exactly correct and a “true” interpretation of reality, but plausible for the purposes of policy making while being constantly tested against real world measurements. The first step is to get the models to mimic the real world. The second step is to tease out man-made vs natural contribution ratios.

    We are a long long way from knowing the models are not false. In the mean time the modellers have significant work to do and I believe that in the background, far from the headlines, they are most likely doing that work as best they or anyone can.

  39. @Steven Mosher:

    Like the fricking two front war assumption in defense planning. with one theatre in fulda gap and the other in NK.

    That was like a zero probability scenario.

    It was actually a two-and-a-half front war strategy. With the “cherry” of mutual assured destruction on top.

    • It was actually a global strategy that was necessary to counter a global threat. Mosher must have forgotten that we were engaged in wars with Soviet client states in Asia in the 50s, 60s and 70s. Meanwhile back in Europe, the Soviet’s bad intentions and offensive military posture were unknown only to the little unilateral disarmament freaks. The Kremlin goons were serious about destroying us and they were arming, funding and directing bad actors all over the world to get it done.

      • “Necessary” is in the eye of the beholder.

      • Don Monfort

        ==>“Necessary” is in the eye of the beholder.

        That’s trivial.

      • “It was actually a global strategy that was necessary to counter a global threat. Mosher must have forgotten that we were engaged in wars with Soviet client states in Asia in the 50s, 60s and 70s. Meanwhile back in Europe, the Soviet’s bad intentions and offensive military posture were unknown only to the little unilateral disarmament freaks. The Kremlin goons were serious about destroying us and they were arming, funding and directing bad actors all over the world to get it done.”

        The scenario was laughable.
        To size the forces and determine the capabilities we had to assume that the huge portions of our assets were tied down in NK.

        Then given a reduced force available for fulda gap we had to design a system that was 10 X…. thats right 10X the capability of a projected red threat. we have to prove air supremacy not merely superiority.

        The projected red threat was an aircraft that the soviets could never hope to build..

        So basically we pretended that many of our forces were tied down in NK
        and then we created a red giant (that was impossible for the soviets to build) , and then we had to design an aircraft that would have an exchange ratio of 10x versus the ASF

        Similar crazy stuff was assumed for the b2 penetration missions.
        basically you got ZERO assets to take down ground based systems
        and you had to penetrate a full up laydown. ZERO defense suppression.

        Could we use tactic rainbow to shut down some air defenses? NOPE.

        for grins
        yf23fighter.com

      • Don Monfort

        That is not very coherent, Steven. It seems like you are claiming that the Soviet Union was a paper tiger with paper airplanes and we planned for 10 X the military capability that we actually needed. My God, we even went for air supremacy, rather than just air superiority. I mean, who really needs air supremacy.

        You obviously never worried about having to actually fight the Soviets, the Red Chinese and their many surrogates. Were you actually involved, even peripherally, in defense policy planning? (That would explain some of the bizarre things I have seen.) Or is all this yammering about a video game that you worked on?

      • @Don Monfort

        ==>“Necessary” is in the eye of the beholder.

        That’s trivial.

        And that’s a non sequitur.

        The only thing bigger than the American defense budget is the pack of lies our government spreads to convince us the expenditures are existentially necessary.

        We should have weaned the Military-Industrial Complex from the taxpayer’s teat after WWII but our leaders decided to provide proxy forces to prop up collapsing colonialism around the globe. And we’re still doing it 70 years later.

        Fortunately, when Bernie Sanders is elected president, I’m sure things will finally change…

      • The scenario was laughable.

        The way you find out that you underspent on national defense is when you are having to learn a new language.

        Most people prefer to overspend a little.

      • opluso

        Defense spending in the last 15 years has gone up from $300 Billion to $600 Billion. Spending on Social Programs has gone up in the last 15 years $1.9 Trillion from $1.1 Trillion to $3 Trillion. Lets see, that is an increase of $300 Billion vs. an increase of $1.9 Trillion. Which one is causing the deficit?

        Bernie is feeding the Liberal Myth that returning to a 91% top marginal rate will help the Middle Class since there was massive income redistribution going on during the 1950s and 1960s. What a joke! There were 201 tax payers in 1954 making over $1 million. There were just 600 tax payers who paid the top marginal rate of 91%. The taxes contributed by the latter group made up 1% of Total Tax revenue and less than .5% by the former group. That is hardly massive income redistribution. The effective rate for all tax payers (taxes paid of Adjusted Gross Income) in 1954 was 13.8%. The latest IRS report (2012) shows an effective tax rate of 14.2%. If we return to the effective tax rate for the top 1% existing in 1954, that would generate about $100 Billion a year, which would put barely a dent into the annual deficit leaving nothing for income redistribution.

        The amount of funding available for income redistribution in 1954, if adjusted for inflation, would be less than $130 Billion vs the current $3 Trillion. Income redistribution has never had it so good.

        There are dozens of reasons for income inequality. The current top marginal rate does not make the top 10.

        But, if you want to believe in Myths, be my guest.

      • Appx. 50,000 USA troops were killed in Korea trying to repel an invasion from the communist north – andproxy war was just a ” police action”. Many of those soldiers were killed at night because the AF did not have night capability. Now we can fly at night and all weather – for good reason. Next war will be different from all previous and if we aren’t prepared many people will cry themselves to sleep for a long time. Btw, note the difference between North and South Korea. Final note, sometimes the war comes to you, like it or not. I’d rather have the modern analog of a superior aircraft than a Solyndra.

      • Lol.

        ncome level Tax rate 2008 PPC Adjusted Income [2]
        up to $2,000.00 20% up to $37,500.00
        $2,000.01 – $4,000.00 22% $37,500 – 75,000
        $4,000.01 – $6,000.00 26% $75,000 – 112,500
        $6,000.01 – $8,000.00 30% $112,500 – 150,000
        $8,000.01 – $10,000.00 34% $150,000 – 187,500
        $10,000.01 – $12,000.00 38% $187,500 – 225,000
        $12,000.01 – $14,000.00 43% $225,000 – 262,500
        $14,000.01 – $16,000.00 47% $262,500 – 300,000
        $16,000.01 – $18,000.00 50% $300,000 – 337,500
        $18,000.01 – $20,000.00 53% $337,500 – 375,000
        $20,000.01 – $22,000.00 56% $375,000 – 412,500
        $22,000.01 – $26,000.00 59% $412,500 – 487,500
        $26,000.01 – $32,000.00 62% $487,500 – 600,000
        $32,000.01 – $38,000.00 65% $600,000 – 712,500
        $38,000.01 – $44,000.00 69% $712,500 – 825,000
        $44,000.01 – $50,000.00 72% $825,000 – 937,500
        $50,000.01 – $60,000.00 75% $937,500 – 1,125,000
        $60,000.01 – $70,000.00 78% $1,125,000 – 1,312,500
        $70,000.01 – $80,000.00 81% $1,312,500 – 1,500,000
        $80,000.01 – $90,000.00 84% $1,500,000 – $1,687,500
        $90,000.01 – $100,000.00 87% $1,687,500 – $1,875,000
        $100,000.01 – $150,000.00 89% $1,875,000 – $2,812,500
        $150,000.01 – $ 200,000.00 90% $2,812,500 – $3,750,000
        $200,000.01 or more 91% $3,750,000 or more

      • Cerescokid

        “There were 201 tax payers in 1954 making over $1 million. There were just 600 tax payers who paid the top marginal rate of 91%. The taxes contributed by the latter group made up 1% of Total Tax revenue and less than .5% by the former group. That is hardly massive income redistribution.”

        Well said. Too many don’t understand the nature of the tax code in the 1950s and blindly follow monolithic group think evangelists on the left that it is indeed possible to tax the country into prosperity. It’s never worked and it never will.

      • Very funny, opie. Bernie Sanders. And it is just as likely that you will be V.P. Don’t quit your day job.

      • @cereskokid

        Sorry I left the /sarc label off the Sanders comment.

        I also consider the deficit (or income redistribution) irrelevant to determining the appropriate level of military spending. Both issues are important on their own but are not related to the “plausible/possible risk” debate we were having.

      • Five stars, JCH, for completely missing the point. What’s new.

        You also probably missed the point that when Clinton raised taxes on the wealthy, it INCREASED income inequality as evidenced by a 300% increase in taxpayers making over $1 million, going up by 180,000. Obama is trying his best to break that record. Let’s see how much greater income inequality is by 2017. He has a chance at surpassing the 180,000.

  40. In business we use risk evaluation all the time. At the moment there are five different popular systems. They are all pretty useless at identifying the best opportunity but excellent at quantifying losses.

    The choice of the evaluation system you use depends very much on the size of the problem. There’s no model in business big enough to handle a planet-sized problem.

    The Cambridge model is thus a welcome development. Even if it is fatally flawed by its purpose of rationalising political stances, it provides a starting point that can be improved upon. Having a target to shoot at gets people pointing in the right direction.

    • David Wojick

      What direction is that? If there is no problem then there is no direction, right? How does one assess a nonexistent risk? By making it up? As I read UAH, climate sensitivity to increasing atmospheric CO2 is zero or thereabouts. But as several have mentioned, increasing CO2 is good because it is the global food supply. Thus the risk of increasing CO2 appears to be negative, that is positively beneficial. Does the Cambridge model allow for this or does it assume adverse impact?

  41. Where is there consideration of a fall of 10C? It is probably more likely than a rise of 10C even with the highest imaginable emissions level.

  42. Here is the ten year annualized rate of forcing change for RCP, and NOAA GHG ( total and portion from CO2 ):
    http://climatewatcher.webs.com/RF10.png

    The CO2 forcing for the last 12 months is noted on the chart above(*).
    FWIW, the last twelve months indicate a slowdown in CO2 accumulation, down to 1.65 ppm per year:
    http://actionwidgets.org/en/e/co2-m/600-keeling.png

    The CO2 accumulation series is noisy, to be sure, but it’s also during 1 and a half El Ninos and warm temperatures which have correlated with greater accumulations in the past. It will be interesting to see if CO2 accumulations are anomalously high the rest of this year with the presumed ENSO event.

  43. Who was the first to predict that SoCal would experience 3 in of rain in a single July?

  44. Curious George

    As long as models do not handle the temperature dependence of a latent heat of water vaporization correctly, I don’t see why to take them seriously.

    • Concur: Given the immaturity of climate science (e.g. lack of knowledge on effects of sun, clouds, water vapor, ocean-atmosphere interface, other feedbacks) climate models are of academic interest only.

  45. Being a luke-warmer, we should aim for the optimum solution. Which js the SRES A1B scenario, this has a peak CO2-emission at 2050.
    https://klimaathype.files.wordpress.com/2015/06/sresrcp.jpg
    Under the transient sensitivity of 1.3 this results in a warming of 1 dgree this century.
    https://klimaathype.files.wordpress.com/2015/06/sres_1_3_sensitivity.png

  46. Don Monfort

    “What is the probability of following a high emissions pathway? Based on an analysis of current policies and plans for major countries and regions, it is very likely that the world will continue to follow a medium to high emissions pathway for the next few decades.”

    Assessments, discussions, speculation about worst case scenarios is not going to change that.

  47. Climate change fits the definition of a risk because it is likely to affect human interests in a negative way, and because many of its consequences are uncertain. We know that adding energy to the Earth system will warm it up, raising temperatures, melting ice, and raising sea levels. But we do not know how fast or how far the climate will warm, and we cannot predict accurately the multitude of associated changes that will take place. The answer to the question ‘how bad could it be?’ is far from obvious.

    We are living through an era in which diverse models make divergent predictions, and all of the models are based on incomplete knowledge, not just incomplete in tiny details, but incomplete in major details. Future warming is unknowable, on this evidence, but ignorance is not total. The most likely scenario for the future is that areas that have experienced alternations of drought and flooding will continue to do so. Flooding damage to bridges in July in Southern California is too unlikely to have been considered by anybody, but recurrent flooding wherever there are washes and river basins is highly likely. A reasonable “worst case” flooding scenario for California can be developed from studying (a) the worst flooding to have occurred in recorded history in each locale; and (b) including the Great Flood of 1863. As far as I can tell, there is no thinking about the history of flooding anywhere in this climate change adaptation/mitigation discussion, only sporadic extreme warnings based on recent events. The July flooding in SoCal destroyed a bridge on I-10 near the AZ border. The $$$ loss of that bridge exceeds the expected $$$ benefit from the reductions in CO2 allegedly produced by the windfarms and solar farms constructed so far. No one could have predicted such a flood in July, but floods occur every year, and every year someplace has a road or a bridge knocked out.

    I am increasingly unimpressed by these fancy-schmancy decision and risk analyses which ignore what I consider the most obvious bad outcome (especially since none of them are new, as far as I can tell), namely that we shall be unprepared for the variations in weather that have been thoroughly documented over the last 150 years (especially since none of these are new, as far as I can tell — guarding against the worst plausible outcome is called “minimax” and has been studied for decades; choosing a course of action which is likely good enough without being demonstrably optimal was named “satisficing” decades ago.)

    If there is anything new here, it is that we should think about climate change instead of panicking, what used to be called “look before you leap”.

    • Matthew

      To me the report does not constitute a risk analysis, but instead is a risk estimate. It is an unimpressive risk analysis because it isn’t one. However, you know that there a plethora tools there can be applied to varying degrees to inform decision making. That aside, OK by magic now you are hired as a technical consultant–for big bucks. What would you do if you had that responsibility? How would you caveat it? Keep in mind you are not restricted in your approach.

      regards,
      mw

      • BTW IMO your thought on the range of the weather is perhaps a very good starting for a lot of analyses…the key being ‘range’.

  48. For the most alarming scenario, there are two groups of predictions:

    Group A (warmer) is based on IPCC science, with our “emissions” being a 90% climate driver, with the sun being of no greater importance than 7% according to Dr. Vahrenholt’s book.
    Since we haven’t had any significant warming for almost 20 years despite significant emissions, it should instead be time for a reassessment of IPCC-science instead of pseudo-scientific speculation about future warming based on a failed dogma.

    Group B (colder) is based on physical science, with recognition of the suns’s importance for our climate. Read Abdussamatov for details. We might be in for a cooling of 1,2 degrees C in a few decades, then again being in the warmest phase of the 100-year solar cycle could limit the amount of cooling somewhat.
    It seems we should wait until the end of the current solar cycle in order to have better predictions for what to expect. A prolonged Maunder-minimum cannot be ruled out, which means the future food supply should be our top priority.

    Regarding Dr. Hansen, as far as I can see he has no core expertise within sea-level predictions and should not be taken seriously.
    Nils Axel Mörner on the other hand is extremely competent in this area, and his latest prediction for sea-level rise this century is 5 cm +/-15 cm. Most of the uncentainty comes from our current inability to predict the depth and length of the coming solar minimum.

  49. Probably the least helpful approach to climate/weather risks is to keep them separate. Even with zero ‘climate change,’ risk from weather events is not zero. Risk from ‘climate change’ is, at most, a slewing of hazardous event types in some direction or another.

    It must be noted that some weather event slewing will be in the less hazardous direction and some in the more hazardous. As an example of this, increased temperatures could easily improve living conditions in colder areas of the world. However, increased equatorial sea water evaporation could increase flooding stress in some parts of the world (maybe, maybe not?). Predicted ‘climate change’ risks are typically only small increment increases (or decreases) in current weather event experiences.

    Furthermore, time frames for changes are expressed in decades or centuries. Normal maintenance, upgrade, replacement, or abandonment of infrastructure elements occurs at a rate that makes cost risks for potential ‘climate change’ impacts low in comparison.

  50. “We know that climate change is a problem ”

    I don’t know that and I’ve been studying this for a while. I haven’t seen any problems at all from it whatsoever, I’ve seen not one believable prediction of damage in the future either.

    Why premise the discussion with an ill-considered assumption?

    • Well it seems that it is a problem if for no other reason than because “We know that climate change is a problem ”. The premise is in play.

      • Jeff is right.

        we know that climate change is no problem.

        bring on the ice ages.

        climate change.. not a problem.

      • Read closer Steve

        Jeff did not write that climate change is no problem. He wrote that he does not see evidence that it is a problem. Big difference

      • > He wrote that he does not see evidence that it is a problem.

        Perhaps Jeff did not see close enough.

        Is there any evidence that an ice age would be a problem? I ain’t ever seen one.

      • It makes some uncomfortable to be in the passenger seat.

        I would suggest that we recognize that the steering wheel we hold is the plastic one mom nature handed us to play with while she drove the car. Not that she might not veer slightly left due to our misbehavior while she smacked us in the head once in a while.

      • Steven Mosher

        Thanks U willard.

        Rob. thank u for playing.

        here is a clue. when anyone says they see no evidence. they are wrong.
        period. doesnt matter what subject you are talking about.

      • I’d like to see Mosher point to the evidence he says is there.

        To date the most convincing piece I’ve seen on possible impact of warming and a changing climate was in the Sports section of the Oregonian a couple years back.

        Discussed the potential impact on salmon from earlier (and possibly lower) runoff and warmer water temps from lower flow levels.

        Another was while working with students in the classroom and in the field doing research on lichens. We had one of the very best scientists in that field working with us. The majority of lichen are fairly sensitive to changes in environmental quality. It is one reason you don’t find them in the same abundance or variety of species in urban areas as in the forest an hour away. NW lichen are exhibiting changes and it seems like climate is one of the leading candidates. Salamanders being pushed out of their habitat by newts is another impact. While not completely related to climate change, they are more adaptable to a wider range in climate and hence have a competative advantage.

        Now if anyone can explain exactly how any of these (or at least the last two) are problems, feel free.

      • Don Monfort

        I see no evidence that Mosher is a pompous unicorn with a K-pop obsession, as many suspect.

        I see no evidence that we need to take costly and drastic measures to avert an Ice Age. So why is willy talking about it?

    • Steve

      Jeff wrote that he did not agree that we know that climate change is a problem and I agree.

      He wrote- “I haven’t seen any problems at all from it whatsoever, I’ve seen not one believable prediction of damage in the future either.”

      Steve- you like to get into the details of what was written. He wrote that he has not seen any problems. That can be true. You like to nit pick wording but in this case what he wrote can easily be argued as 100% accurate.

      Now in a more honest exchange- has the climate changed negatively anywhere as a result of humans releasing CO2? The answer is obviously yes- it must be.

      Can you point out the largest 3 or 4 in your opinion???

      • Thanks Rob. I like Steve, always have, but he does enjoy playing the foil in the same way Nick Stokes does. I seem to have tweaked him though so I’m curious how he will answer your question.

      • imo highly unlikely he will answer

      • Well Steve knows I’ve got some street cred so we have a shot. I was not being facetious in my interest in my reply. I am truly curious.

        There were at least 3 mosheresque replies I deleted before being myself. I’m sure that if he reversed his own role he could have predicted 2/3 of them. There is an entertainment aspect to blogging that even leftstream psychologists haven’t figured out.

      • My interes int his reply!! crap who writes these things!

      • Well Rob, it looks like you were right and he won’t be replying. I sure don’t see any evidence of it. I guess that makes it twice you were right and per Steve’s claim that if I don’t see evidence of damages due to AGW or his reply, twice I am wrong.

      • In 2015? Lol.

    • Well Steve, I would suggest that when people make altruistic statements like: “when anyone says they see no evidence. they are wrong” they are often the ones who are standing in the poo pile.

      Perhaps you should reconsider my comment in the form of AGW in which context “climate change” was meant, and show me where I’m wrong. I sure don’t mind learning.

      It is my considered opinion that we have not established any significant negative effects related to global warming. I don’t see them anywhere. Similarly, I don’t see a lot of positive effects but we can predict some of them: https://noconsensus.wordpress.com/2015/07/22/a-different-opinion/

    • “We know that climate change is a problem ”

      JeffId, “I don’t know that and I’ve been studying this for a while.”

      Mosher, “Jeff is right.

      we know that climate change is no problem.

      bring on the ice ages.

      climate change.. not a problem.”

      Funny. An absolutely stable climate is likely the worst case scenario. That would end up being the “ideal” condition for some biological organism to win outright which isn’t “nature’s” way. Climate change is the norm.

      • Well, there is nothing stable about the local climate.

      • Climate changes, therefore any change is good.

      • Willard, “Climate changes, therefore any change is good.”

        No, climate changes therefore deal with it. If you consider any local climate, that would be an average of weather for at least 30 years, it changes. Pick whatever paleo proxy you like for that locality and the longer term climate varies by at least +/- 1 C degree and there are droughts, floods, heat waves, cold snaps, all part of that local climate.

      • Climate changes, deals with it, however “it” is defined, so it’s all good.

      • Don Monfort

        Show us your evidence for an Ice Age, willy. Now that an eminent scholar of some obscure subject like yourself has brought it up, we are worried.

      • Willard, “however “it” is defined.”

        Now we cannot have a clear definition, what fun would that be? What we have is “Climate Change”, intentionally vague. “If we reduce CO2 emissions to 1950 levels we will “stop” climate change and save the world as we know it.”

        Nope, don’t think so.

        “If we reduce CO2 emissions to 1950 levels we will increase Atlantic Tropical Cyclones to 1950s levels.”

        Nope, don’t think so.

        “If we reduce CO2 emissions to 1950s levels we may reduce the “global mean surface temperature anomaly” by 0.8 C after allowing sufficient time for the “global mean surface temperature anomaly” to “stabilize” at some “normal” level of “natural” variability.”

        Now that is vague enough to be somewhat accurate.

        How about if we reduce CO2 emissions to pre-industrial levels, will climate be “stabilized” and “ideal”?

        https://climateaudit.files.wordpress.com/2015/01/2014-bas-hockey-stick.png

      • > Show us your evidence for an Ice Age […]

        Here you go, Don Don:

        An ice age is a period of long-term reduction in the temperature of Earth’s surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of cold climate are termed “glacial periods” (or alternatively “glacials” or “glaciations” or colloquially as “ice age”), and intermittent warm periods are called “interglacials”.

        https://en.wikipedia.org/wiki/Ice_age

        You want dinosaurs too? Here:

        Dinosaurs are a diverse group of animals of the clade Dinosauria. They first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the beginning of the Jurassic (about 201 million years ago) until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups (and some three-quarters of plant and animal species on Earth) at the close of the Mesozoic Era.

        https://en.wikipedia.org/wiki/Dinosaur

        I ain’t ever seen neither one.

        Both are problematic from a verificationist point of view.

  51. Re Dr. Curry’s definition — Plausible: a future scenario that cannot be rejected or falsified based on background knowledge. Scenario falsification was discussed in a previous CE thread.

    So, the more ignorant (less background knowledge) you have, the more plausible a future scenario becomes (and the more extreme scenarios that become plausible are) .

    Really? That’s going to be your definition for engineering the climate?

    • Good point, I clearly need an addendum to my definitions.

    • > So, the more ignorant (less background knowledge) you have, the more plausible a future scenario becomes (and the more extreme scenarios that become plausible are) .

      Not really. It just states a necessary condition for some scenario to be plausible. Think of it as an on/off switch, not a dimmer.

    • So, the more ignorant (less background knowledge) you have, the more plausible a future scenario becomes (and the more extreme scenarios that become plausible are) .

      Sure. Prior to radar investigations of the Solar System, the idea of an asteroid about to hit Earth seemed more plausible than it does now.

    • Judith: Shorter Oxford Dictionary 1959: Plausible: a. 1. Deserving of applause; praiseworthy; commendable – 1711; 2. Acceptable, agreeable, pleasing; generally acceptable, popular – 1828; 3. Having a show of truth, reasonableness or worth; apparently acceptable; fair-seeming, specious. (Chiefly of arguments or statements (1565); b. Of persons: Fair-spoken (with implication of deceit) 1846. B. That which is plausible; a plausible statement, etc 1654. 3. Little aided by conjecture, however p. b. A cunning kind of fellow 1875.

      Concise OD 2001: plausible adj. apparently reasonable or probable, without necessarily being so.

      So a “plausible” scenario is one which you should approach with circumspection; don’t bet your house on it. Or the source of general well-being.

      As I said earlier, I disagree that policy should be driven by the worst plausible warming scenario. Other posters have also given strong grounds for not basing policy on such scenarios. So on this issue perhaps it is not just your definitions which need an addendum.

      Faustino

    • Plausible: a future scenario that fits within the constraints of current knowledge yet cannot be proven, rejected or falsified based on gaps in that knowledge.

  52. David Wojick

    UAH shows no GHG warming for its entire measurement record (from 1978). Does it falsify all GHG driven warming scenarios, especially the more extreme ones with CS above 2 degrees? Contrary to Popper, falsification is not a feature of science, because we are dealing with inductive logic. What one is looking for is disconfirmation. I am inclined to think that a high CS has been disconfirmed, but that is a personal judgement, as is all risk assessment. I see no risk whatever in increasing CO2 levels, only benefits.

    • What one is looking for is disconfirmation.

      +1

      not many skeptics get that falsification is not how science works

      • Oh well, I was looking at comments on the journal to see if they appeared to be pal review or tough minded.

        UAH shows warming since 1978; by the end of 2015 it’s going to a show a ton more because it skyrockets for El Nino events.

      • ACP is a journal that is pretty tough minded on its review process. If after the solicited and contributed reviews, available online, the editorial board deems that the paper is worth publishing, it becomes published in ACP and is no longer a discussion paper. I really like this model for peer review. However, the editorial board is not that well suited for evaluating climate dynamics papers.

        Hansen should have waited until the paper was available online before issuing his press release.

      • Re SM’s statement: “. . . falsification is not how science works”, it isn’t hard to find those who don’t agree. Look at https://en.wikipedia.org/wiki/Falsifiability to start and find more as necessary to educate yourself.

      • David Wojick

        Philip: As SM notes, many people do not understand the difference between falsification and disconfirmation. But your Wikipedia citation is to a different concept, which is falsifiability, which really means that there can be evidence against the hypothesis. This should really be termed disconfirmationability. The point is that we are talking about the weight of evidence, which is seldom absolute, perhaps never. Falsification suggests an absolute result.

      • > Falsification suggests an absolute result.

        Yet here’s Sir Karl, from his Realism and the Aim of Science:

        [I]t may happen that we condemn an innocent hypothesis. As I have shown [in Logic of Scientific Discovery], an element of free choice and of decision is always involved in accepting a refutation, or in attributing it to one hypothesis rather than the other.

        For a neverending discussion of falsification, cf. the comment thread at Bart’s:

        https://ourchangingclimate.wordpress.com/2014/02/17/is-climate-science-falsifiable

      • David Wojick says:

        . . . your Wikipedia citation is to a different concept, which is falsifiability, which really means that there can be evidence against the hypothesis. This should really be termed disconfirmationability.

        So, you argue that falsifiability (that it is possible to falsify) does not mean that falsification is how science works. Confused thinking on your part; you should study some of the discussions among scientists that are available before you show your uninformed opinion.

        As to whether “falsifiability” should be “disconfirmationability”, you should make that point to Wikipedia, not me. I think you violate Occam’s Razor both in English and in science on this point, but they might agree with you.

      • Professor Curry,

        “Hansen should have waited until the paper was available online before issuing his press release.”

        He’s following the successful template of Carl Sagan, who published “The nuclear winter” in Parade magazine (30 October 1983) — followed by a massive media campaign. The actual paper appeared the 23 December issue of Science, and was far weaker than the decisive analysis Sagan described.

        I expect that we’ll see much more of this as we approach the Paris Conference.

    • > we are dealing with inductive logic.

      A citation might be nice.

      • David Wojick

        Sorry Willard. If you do not understand the role that inductive logic plays in science then I cannot help you. It is the difference between science and math, hence large.

      • > If you do not understand the role that inductive logic plays in science then I cannot help you.

        Of course you can’t help, DavidW, since your posturing is quite implausible. Start here:

        This article begins by briefly reviewing Hume’s formulation of the problem of the justification of induction. Then we jump to the middle of the twentieth century and Hempel’s pioneering work on confirmation. After looking at Popper’s falsificationism and the hypothetico-deductive method of hypotheses testing, the notion of probability, as it was defined by Kolmogorov, is introduced. Probability theory is the main mathematical tool for Carnap’s inductive logic as well as for Bayesian confirmation theory. Carnap’s inductive logic is based on a logical interpretation of probability, which will be discussed at some length. However, his heroic efforts to construct a logical probability measure in purely syntactical terms can be considered to have failed. Goodman’s new riddle of induction will serve to illustrate the shortcomings of such a purely syntactical approach to confirmation. Carnap’s work is nevertheless important because today’s most popular theory of confirmation—Bayesian confirmation theory—is to a great extent the result of replacing Carnap’s logical interpretation of probability with a subjective interpretation as degree of belief qua fair betting ratio. The rest of the article will mainly be concerned with Bayesian confirmation theory, although the final section will mention some alternative views on confirmation and induction.

        http://www.iep.utm.edu/conf-ind/

        The Dutch book argument may provide an answer to Mr. T’s concerns regarding likelihood functions in climate projections.

      • Here:

        Bayesian confirmation theory is by far the most popular and elaborated theory of confirmation. It has its origins in Rudolf Carnap’s work on inductive logic (Carnap 1950/1962), but relieves itself from defining confirmation in terms of logical probability.

        http://www.iep.utm.edu/conf-ind/#H6

    • My father’s Admiral almost got everybody killed, and perhaps now we know why; perhaps he too was up-and-down blind

  53. Craig Loehle

    If a business when considering investments only considered the worst case, and not the potential upside, it would never open a new store or put out a new product. One must consider also the positive cases. If you do nothing about climate and crop yield doubles (CO2) and the economies grow so no one is starving, that is a pretty strong upside. Framing it only in terms of worst cases is disingenuous.

    • Disingenuous arguments for CO2 mitigation—they are so common nowadays that they have actually become the norm.

      Ever notice how ANY bad weather event is currently automatically assumed or at least claimed to be the result of AGW.

      Ever notice how any lower trend of bad weather is not mentioned?

      It is remotely plausible that AGW may result in net negative conditions, but there is no reliable evidence currently to support that belief is likely to occur. That does not stop the propaganda in the media however.

  54. “We know that climate change is a problem”
    That is where it went wrong. We don’t know. When you start defining something as a problem, every one goes into solution mode, and assumes it is a problem, even if it is only a very speculative self invented problem.
    Only a few have the courage to ask in what way it is a problem.

  55. Craig Loehle

    I would also suggest that the risk of hysteria and the adoption of stupid and useless policies (windmills, for example) is greater than the risk of 10 foot sea level rise (which by the way would not be world ending either).

    • Windmills are not stupid if they generate a profit for the owner. They do occasionally and will more over time imo as designs become lower maintenance.

    • Well…

      If we remove the renewable subsidies and windmills and black glass still gets deployed it sort of is what it is.

      If we remove the subsidies I really don’t have strong feelings about renewables. They will get deployed where they are cost effective and can be integrated into the grid.

      We are going to run out of fossil fuel and fossil fuel prices will rise until renewables are feasible Subsidizing renewables just carrots grid operators into making bad choices and deploying maturing technology too early.

  56. Spent a lot of time at the Cambridge site, reading the report, looking at the process that generated it, thanks to Judith’s post. Concluded wasted time on a biased rather than objective process. Was going to comment on that (hosted by Center for study of Existential Risk, who knew?, and Skoll (EBay founder, not snuff) Global Threats Fund, oh boy more SF angst), but too long and complicated for remaining time available today. Arts of Truth stuff.

    Rather, only a mild logic rebuke to Judith’ s useful distinction between possible and probable, which results in making any risk analysis (not based on actuarial like statistics) just a political craps shoot. Done as parody.

    Using the post notions of possible and plausible, it is not only possible, it is quite plausible that we will be wiped out soon by a cosmic strike (asteroid, comet, whatever) so per the precautionary principle should devote $trillions to monitoring and prevention (I dunno, an ‘ARGO’ system for monitoring asteroids (been seriously proposed), atomic deflector missiles (ditto), Bruce Willis on permanent Standby at Space X… Whatever anyone thinks is a plausible mitigation scheme like renewables and CCS).
    It is plausible by definition because it happened once globally to dinosaurs (KT iridium layer. Alvarez hypothesis, Chixilub, 60mya). A minor variant warning happened at Tunguska in 1908, just like Hurricane Sandy hit NYC in 2012. (Essay Sandy was Weather incorporated by reference as part of this parody). Only a century ago. A minor minor event hit Chelyabinsk in 2013 and injured 1200 people. Only two years ago. The observed cosmic frequency is increasing. Like observed CO2 is rising. The plausible risk of this worst case scenario is rising (astronomically)!
    So cosmic impact is by post definition a plausible worst case scenario against which we must act to save our childrens children (of whatever generation alarmists chose to insert here). A Papal encyclical will shortly be forthcoming with support from the Varican Observatory (which does exist). This ‘existential risk’ is of biblical proportions, would definitely harm the environment and the poor, and could be prevented by somehow acting now.
    Here endeth the parody.

      • Mosher, there is very little we agree upon. A basic Berkeley v. ‘real world’ perspective. But this TED talk you highlighted is priceless, making yet again (IMO) my parody point, sort of. Should be viewed by all denizens.
        Regards to you, and many thanks for that riposte.

      • So many problems so little time. The drugs and counselling might work for more that one problem.

      • Steven Mosher

        Thanks Rud.

        If you want to work together to improve the record. drop me a line.

    • Rud
      B612 foundation has realistic plans to launch a monitoring satellite for near earth objects that would detect threats years in advance. Enough time to deflect. Costs about $480,000,000, about what a billionaire donor needs to give for an art gallery and this could save the planet. If a large one hits it would cook the earth at roughly 500 F for months. Leaves only underwater creatures and burrowing ones to repopulate. A real risk although a small one but every 60 million years or so. Wham!

      The game in play by the activists and President is not so much preventing CAGW but taking control of the economy from those pesky free markets. It is much easier to defeat a pretend foe than face a real one, that one can actually see the results. We seem to do poorly with jihadists.

      Keep communicating, You do a great job of logical and rationale discussions.
      Scott

    • > useful distinction between possible and probable

      … which we can find in any good online dictionary.

      • Ah, Willard. Perhaps. Why not also post your trivial on line dictionary link?
        Better question to you, why not post this salient observation upthread in your many previous comments?
        (I admit to too much ennui to have attempted actually counting yours upthread. Denizens can do the now indelible numeric analysis of your BS.

      • > Why not also post your trivial on line dictionary link?

        Because quoting online dictionaries is a specialty among parsomatic artists, like we often encounter at Lucia’s. Since you insist:

        : a chance that something might exist, happen, or be true : the state or fact of being possible

        : something that might be done or might happen : something that is possible

        http://www.merriam-webster.com/dictionary/possibility

        : appearing worthy of belief

        http://www.merriam-webster.com/dictionary/plausible

        Denizens (go team!) can see that possibility is ontological (it refers to a state of affairs) while plausibility is epistemological, as it refers to a belief over that state of affairs. Logicians (no, not DavidW, real ones) might also refer to alethic and epistemic interpretations of modal logics.

        One way to merge the two universes of discourse would be the ambiguously named possibility theory:

        The name “Theory of Possibility” was coined by Zadeh [119]. In Zadeh’s view, possibility distributions were meant to provide a graded semantics
        to natural language statements. However, possibility and necessity measures can also be the basis of a full-fledged representation of partial belief that parallels probability. It can be seen either as a coarse, non-numerical version of probability theory, or a framework for reasoning with extreme probabilities (Spohn [102]), or yet a simple approach to reaso
        ning with imprecise probabilities [36].

        http://www.irit.fr/~Didier.Dubois/Papers0804/D_CSDA06.pdf

        Except for some byzantine refinements it provides over fuzzy logic, I’m not sure it’s worth handwaving to all this.

        The lore of our fathers is a fabric of sentences.

  57. http://notrickszone.com/2015/07/21/noaa-record-heat-claims-dismissed-in-independent-datasets-we-see-widespread-model-failures-says-expert-meteorologist/#sthash.68LTrXRa.dpbs

    One problem is taking the wrong action due to the wrong climate forecast which is a very likely outcome.

    Not to mention the manipulation of NOAA data.

  58. http://www.leif.org/EOS/2011GL050168.pdf

    This article is good but it needs to emphasize the prolonged minimum solar /volcanic climate connection( which it does not mention ), and other prolonged minimum solar climate connections such as an increase in galactic cosmic rays more clouds, a more meridional atmospheric circulation due to ozone distribution/concentration changes (which it does not do ) which all lead to cooler temperatures and more extremes .

    In addition they do not factor the relative strength of the earth’s magnetic field.

    When this is added to the context of this article I think one has a comprehensive explanation as to how the start of the Little Ice Age following the Medieval Warm Period may have taken place and how like then (around 1275 AD) is similar to today with perhaps a similar result taken place going forward from this point in time.

    I want to add the Wolf Solar Minimum went from 1280-1350 AD ,followed by the Sporer Minimum from 1450-1550 AD.

    This Wolf Minimum corresponding to the onset of the Little Ice Age.

    John Casey the head of the Space and Science Center, has shown through the data a prolonged minimum solar event/major volcanic eruption correlation.

    Today, I say again is very similar to 1275 AD. If prolonged minimum solar conditions become entrenched (similar to the Wolf Minimum) accompanied by Major Volcanic Activity I say a Little Ice Age will once again be in the making.

    Milankovitch Cycles still favoring cold N.H. summers if not more so then during the last Little Ice Age , while the Geo Magnetic Field is weaker in contrast to the last Little Ice Age.

    I would not be surprised if the next Little Ice Age comes about if the prolonged solar minimum expectations are realized in full.

    http://spaceandscience.net/sitebuildercontent/sitebuilderfiles/ssrcresearchreport1-2010geophysicalevents.pdf

    Once my low average solar parameters are attained we will see if this line of reasoning on the climate going forward is correct. I think it will be and that is the danger because mainstream keeps pushing global warming.

  59. The cosmic impact is also being over looked as ristvan pointed out.

  60. From the Slate piece on this ‘paper’:

    “One necessary note of caution: Hansen’s study comes via a nontraditional publishing decision by its authors. The study will be published in Atmospheric Chemistry and Physics, an open-access “discussion” journal, and will not have formal peer review prior to its appearance online later this week. The complete discussion draft circulated to journalists was 66 pages long, and included more than 300 references. The peer review will take place in real time, with responses to the work by other scientists also published online.”

    • So, we can shred immediately. Bet they wont post shreds, only accolades.
      Bet?

      • True. Peer review accolades in real time. I can visualize a Skeptical Science line-up of moderators like a PBS funding drive; rubber stamping green accolades and invented criticisms anointed for spectacle defeat as red meat. Hard critical questions will be filed in cyberspace purgatory for temporal punishment while conjuring a snarky rebuttal; or left for a Dante circle of hell fate to be determined later, at least if McNutt has a say.

      • Jungle,

        “True. Peer review accolades in real time. I can visualize a Skeptical Science line-up of moderators like a PBS funding drive; rubber stamping green accolades and invented criticisms anointed for spectacle defeat as red meat. Hard critical questions will be filed in cyberspace purgatory for temporal punishment while conjuring a snarky rebuttal; or left for a Dante circle of hell fate to be determined later, at least if McNutt has a say.”

        Now THAT is funny! :) Your post belongs on a bronze plaque somewhere.

        Maybe Cook et al is available to help with peer review. /snark

      • All you have to do is go to the website and read.

      • All you have to do is go to the website and read.

        Not yet.

        Hansen apparently can’t wait to scare the public through the press before having anyone actually read the paper.

        By the time the paper’s out, it won’t matter to the public who remember something about the world ending in the news.

      • There are a bunch of papers there in the process of being reviewed. You can read the comments on the few that have comments.

  61. Oh well.

    Climate = average(weather).

    How can it kill thee?
    Let me count the ways . . .

    Worst scenario? You die. Way to avoid it? Don’t be there at the time!

    Use your best judgement, listen to others as much or as little as you want, then make up your mind. There are any number of strident fools demanding that you bend to their will.

    They’re no more liable to be right than you. Life is not a rehearsal, and is useful for only one thing – to be enjoyed. That’s my view anyway. Maybe I’m wrong.

    Would you rather be happy, or would you rather be right?

    Cheers.

  62. What is the plausible ‘worst scenario’ for climate change? (rather a silly question) — An Ice-Age of course !!

  63. As it’s been described, the attention on AGW seems to come with little recognition for other potential existential threats; as if looking down a tube and seeing only AGW mitigation without peripheral vision. Alternate disaster scenarios with the potential of shorter-term realization that could prove more costly, perhaps more likely, are evident.

    But

    Where’s the massive technological curve that’s been self evident for over a century fit into the equation as an alternate, and perhaps preferable, conviction over the presumed need for punitive mitigation? I’m not referring to the current stable of technologies; black glass, wind, et al; but rather new paradigms. An excuse for this to be ignored could be, “one can’t factor something that hasn’t been invented yet”, but why not? We don’t have a prognosis for AGW and nothing is stopping the warmer crowd from developing lavish punitive measures for mitigation even though much of the science isn’t observable. So we’ve embraced pessimism and discarded prudent optimism; because our technology curve is observable. We may not know everything that will be developed now, but we do know how fast technology in general has advanced. The Wright brothers flew a little over 100 years ago. Determination isn’t needed to find alternative energy sources, the work’s already being done. What’s being defined now as a threat can be potentially non existent in 30-50 years through technology, or mostly mitigated.

    So, out of sight out of mind? For example Lockheed Martin Skunk Works last year announced its High Beta fusion reactor, and proclaimed they’ll have a prototype in 5 years, and a product in 10. Outlandish? Maybe, they’ve been looked at with a skeptical eye which may be appropriate. But it’s Skunk Works, ya know? Why would they put their reputation on the line for something impossible if they don’t know something the rest of us don’t. This only serves as an example. If it’s not them, there will be something else. It’s going to happen. Perhaps breakthrough advances in sequestration technology. Just sayin.

  64. curryja – Judith

    Another enjoyable post. The pace of blogs is a killer, so I have decided on trying something new. Where others enjoy going back and forth here is my quick perspective from a backwater. In a nutshell like some others here I am not at ease with singular worst case estimates. My comments however are not so much a critique as much as the current status of trying to get at that discomfort. That said:

    A pre-emptive clarification on [my] language — In the particular risk language with which I am most familiar a scenario is not an outcome. A scenario is a prescribed set of lifestyle circumstances/activities characterized and modeled in terms of constants [single-valued], parameters [‘single’ valued], and uncertainties [multi-valued]. Because of the multivalued uncertainties and because multiple alternatives condition those uncertainties a single lifestyle will have multiple risk outcomes. The ‘scenarios’ discussed in this post are what I would call outcomes, but that is a matter of usage in different circles, i.e., my quibble is not semantic. Language always can be worked out. However, I mostly will use my terminology* because here it is important in my comment to distinguish between circumstances modeled and outcome. … my apologies, I will try to keep the distinctions clear.
    ———
    * For example what this post calls a ‘scenario’ I’ll refer to as a ‘[lifestyle] scenario outcome’ or just an ‘outcome’. The qualifying term ‘[lifestyle] scenario’ refers the set of lifestyles circumstances of a population of interest (or in my experience individual).

    So what aspects of using a worst case [lifestyle] scenario outcome (post’s scenario) catch my interest in this cursory look?

    1.) At this point ‘possible versus plausible’ is a secondary consideration for me. Basically I am open to the idea of different approaches—quantitative, qualitative, linguistic, etc.—to risk characterization. It is natural to extend this flexibility to specifying criteria. I see ‘possibility versus plausibility’ as a subject of formulating and setting criteria. Quantitative decision models for example may use numeric criteria, fuzzy models may use fuzzy values and fuzzy criteria, qualitative models may use landmarks. While there is freedom in selecting types of models and criteria there are relevant tradeoffs, e.g., between form of expression and precision [and third party expectations], that have to be managed.

    2.) A “worst case scenario and outcome” takes too much attention away from the role that alternative selection can play in the severity of downstream impacts. That is, alternative selections condition the outcomes. Because the a given [lifestyle] scenario, e.g., subsistence living on the coast, urban area on the coast, etc., often can and will be considered under different decision alternatives it likely will have different outcomes under those alternatives. So determination of ‘worst case’ is tied to alternatives considered and the selection of a worst case from that set.

    3.) Some sense of things hanging in the air. The obvious response to a worst case scenario is, “How did you arrive at that particular worst case?” The answer is likely something like, “Well we considered/analyzed a number of [lifestyle] scenarios and their outcomes under there these alternatives and arrived to the worst case as a result of those analyses. In other words to determine a worst case you necessarily must consider more than that case. So why would you[one] not use all of the results? This is an awkward situation, e.g., it can invite suspicion of motives.

    NIce exercise.

  65. @mwgrant: In a nutshell like some others here I am not at ease with singular worst case estimates

    Right, like I said here:

    http://judithcurry.com/2015/07/20/risk-assessment-what-is-the-plausible-worst-scenario-for-climate-change/#comment-719712

    Those who don’t see any connection between CO2 and temperature won’t like any cases, best or worst.

    Those expecting CO2 to suddenly dive down for some reason won’t like worst case estimates at all.

    Those expecting CO2 to follow the past 265 years, the case I wrote about in the above, won’t like the worst case either, since that would predict considerably greater than 1000 ppmv of CO2 in 2100.

    RPC8.5 is not the worst case, merely the most likely case based on prior data.

  66. Vaughan Pratt,

    My discomfort is not with any particular worst cases, but instead is a general concern with the use of a worst case in looking at the risks. To me it is an approach that is messy both in concept and in implementation.

    I feel strongly that the characterization and formulation of the policy decision(s) is getting far too little attention. When one is arguing for or against particular scenarios as is so typical here and elsewhere during the formulation of an approach one is getting way ahead of the game.

  67. Worst case scenario?

    Carbon based fuel is declared a Global Human Resource and as such is collectivized under UN authority. An international superagency is established to regulate production, distribution, pricing and consumption. The agency controls all cash flows and is run by people that make Sepp Blatter look like Mother Teresa

    Implausible? Well, we still have plenty of coal, and since fracking pushed “Peak Oil” way down the road the new mantra is “Leave it in the ground”. Should divestment fail to do the trick, then political intervention will be required, Of course, maybe i’m just spending too much time over at The Guardian.

    • They’re starting to get desperate.

    • Fracking has pushed peak gas way down the road. Not peak oil. You need to study the TRR estimates, and realize how much misleading hype is out in the MSM. Essays Reserve Reservations(monterey shale geology) and Matryoshka Reserves (bahzenov shale geology, world’s largest) would be good starting points.

  68. Having now looked at the Cambridge risk assessment report I have to say I am disappointed in its quality. Overall, it is hard to distinguish it from other compilations of climate risk/response. They stress the high-end projections and assume the models actually inform us about local and regional flood, drought, etc., decades into the future.

    Yet despite their climate clairvoyance for river valleys and cropland regions decades hence, they absurdly assert that “climate hardly changed at all in the first ten thousand years of human civilization”. Perhaps they should have checked with Cambridge’s Division of Archaeology before printing that nonsense. That ignorant statement was followed by “even the 0.8 C of climate change we have seen so far is now causing us significant problems.” That is EPA-quality dreck.

    Such fundamental inaccuracy and unwarranted assumption undermines any authority they may possess on rational risk assessment. If you do not accurately comprehend current and prior climate fluctuations (which apparently never happened), why should we trust your assessment of future climate risks?

    It is difficult to find examples of the successful implementation of a comprehensive 5 year plan at the national level. The idea that a globally comprehensive, continually coordinated 100+ year plan is achievable is hard to take seriously.

    • Craig Loehle

      For example, 6000 years ago North Africa had huge lakes and was a grassland to semi-desert, not a wasteland. If that isn’t a huge change, I don’t know what is. We also know that various civilizations failed due to drought (e.g., Maya, SW US Indians, others).

      • On the other hand the changing rain tracks may reestablish the North African Wet period and the Sahara green and fill with hippos and crocodiles like before. That is when civilization started and the stress of climate change response resulted in human behavior changes.

        This is all so interesting. The big problem is the models don’t work well compared to observations unless one goes back to change historical observations. Not only can’t they predict accurately, they only work when adjusting the past. What a failure of objective science.
        Scott

    • I found the same. The process that produced it was biased from the gitgo by the sponsors. Evidentiary quality is very poor. Recalls my very first guest post here back in 2012? Yield impacts on US maize. Showed the dishonest political communications process around a fatally flawed paper. The sort of stuff the Cambride process picked and used without question.

  69. AGW says humanity’s CO2 has heated the globe over the last half of the 20th century. Let’s look at the facts: there was a slight cooling from 1940-1975 followed by 30 years of warming to where we are now: going on 20 years of no change and Russian scientists predicting the next ice age in 15 years.

    AGW has become a conventional wisdom based on what Nigel Lawson called, “a battery of essentially spurious statistics based on theoretical models and conjectural worst cases.” As Lawson concluded back in 2007, “This is clearly no basis for policy decisions which could have the most profound adverse effect on people’s lives.”

  70. Evidently, the Washington Post got the usual suspects’ reviews of the thing.

    Here’s Trenberth’s take:

    Kevin Trenberth, an influential climate researcher at the National Center for Atmospheric Research in Boulder, Colorado, was critical of the paper, calling it “provocative and intriguing but rife with speculation and ‘what if’ scenarios.” Trenberth objected in particular to the climate modeling scenarios used to study freshwater injection as ice sheets melt. “These experiments introduce a lot of very cold fresh water in various places, and then they see what happens,” he wrote by email. “The question is how relevant these are to the real world and what is happening as global warming progresses? They do not seem at all realistic to me.

    “There are way too many assumptions and extrapolations for anything here to be taken seriously other than to promote further studies,” Trenberth wrote.

  71. I am intrigued by the links to the Rutledge and King posts challenging the plausibility of RCP8.5 because that pathway is similar to the EPA’s business-usual RPC in its recent “Benefits of Global Action” report (http://www2.epa.gov/sites/production/files/2015-06/documents/cirareport.pdf).

    Rutledge, commenting on IPCC WGIII, claims RCP8.5 assumes coal combustion totalling two times world reserves by 2100 and seven times reserves by 2500. He notes that WGIII is “coy” about coal, but apparently so much so that I cannot verify Rutledge’s analysis. Alas, he did not provide citations allowing readers to examine the pertinent IPCC texts and judge for themselves.

    One of the few discussions of coal reserves I find in WGIII is Chapt. 7, p. 525: “For both reserves and resources, the quantity of hard (black) coal significantly outnumbers the quantity of lignite (brown coal), and despite resources being far greater than reserves, the possibility for resources to cross over to reserves is expected to be limited since coal reserves are likely to last around 100 years at current rates of production (Rogner et al., 2012).”

    That excerpt would appear to conflict with Rutledge’s assessment of WGIII’s assumptions regarding coal burn.

    • Marco,

      Rutledge is right. But it’s not an important point. The geological work to reliably estimate mineral reserves is expensive, and so companies only do so to the degree necessary. They’re uninterested in what they’ll be burning 50 years from now.

      Also, “reserves” come in 3 flavors.

      “1P reserves” = proven reserves (both proved developed reserves + proved undeveloped reserves).
      “2P reserves” = 1P + probable reserves = “proved AND probable.”
      “3P reserves” = the sum of 2P + possible reserves = “proven AND probable AND possible.”

      Estimates of the quantity of 3P reserves are little more than guesses, and their energy content is a wild guess. Some might be hard coal, some might have the BTU content of kitty litter.

      For a more analytical look at RCP8.5 assumptions about coal use — and the actual trend of coal use — see: http://fabiusmaximus.com/2015/07/13/coal-climate-apocalypse-87192/

    • Marlo and Editor:

      I believe Marlo is correct regarding WGIII and coal burning. Rutledge relied upon a paper that appears to have considered the possibility of extrapolating beyond resource capacity (see quote below). I do agree with Editor that the confusion probably arises in the differing definitions — “economically recoverable” vs “resource” and how various sources project them into the future.

      Regardless, there is little doubt that global economies could burn 7 to 10 Gt of coal per year through the end of this century, if economic and regulatory conditions allow.

      Rutledge’s source (together with the Figure 5 that he used) can be found here:
      http://link.springer.com/article/10.1007/s10584-011-0156-z#page-1

      cheers,

      Kent Jeffreys

      Relevant section from the 2011 source paper:

      Several alternative extensions were considered for each RCP. For RCP8.5, the full range​ ​of possible extensions ranged from a constant forcing that results from simply keeping​ ​concentrations constant after 2100 to very high levels that result from assuming that​ ​emissions stay constant until 2300. After consultations with the respective expert groups an intermediate extension was selected. This extension avoids a possible discontinuity in​ ​emissions trends (that would arise from keeping concentrations constant), and avoids issues​ ​of resource availability that a higher extension might raise. Keeping emissions constant​ ​would have resulted in CO2 concentration of around 3000 ppm by 2300. The adopted​ ​RCP8.5 extension (ECP8.5) leads to a CO2 stabilization after 2250 at roughly 2000 ppm, or​ ​more than 7-times pre-industrial CO2 concentrations. The total forcing of this ECP8.5 is​ ​hence approximately twice as high as the next highest ECP (ECP6) (see Fig. 4 below). This​ ​high forcing for ECP8.5 is significantly above the highest forcing level that was considered​ ​in CMIP3 on the basis of IPCC SRES scenarios (i.e., approximately 700 ppm in A1B).

  72. At Climate Lab Book, Ed Hawkins has posted a “back of the envelope” calculation of GHG radiative forcing compared to observed warming. Taken at face value, it seems to largely agree with the Lewis/Curry climate sensitivity paper. In fact, without assuming that non-GHG forcing and natural variation are negating a large portion of GHG-related forcing, Hawkins’ results seem a bit lower than Lewis/Curry on TCR.

    Perhaps this could provide a common starting point for moving away from these “worst case” risk assessments. I know, I know … that is just wishful thinking on my part.

    http://www.climate-lab-book.ac.uk/2015/back-of-the-envelope-attribution/

    • http://newscenter.lbl.gov/2015/02/25/co2-greenhouse-effect-increase/

      Measurement at two sites indicates downwelling IR is increasing 0.2 W/m2 for 22 PPM (2000-2011 study).

      The traditional IPCC log formula for CO2 only forcing predicts a 50% higher result.

      The IPCC TSR is 2X CO2 forcing – that is 3 times to high.

      From this you can infer that the IPCC ECS which has a 3.0°C value is 3 times too high.

      Perhaps someone could explain how you can empirically measure the IR forcing to have the equivalent of a 0.65°C TSR value yet still claim the forcing is much higher in scientific papers.

      Further – with the actual CO2 lifetimes much shorter than the IPCC century (6 GT/y of absorption guarantees a short lifetime), the ECS is a moot point since the CO2 level won’t be elevated above 400 PPM for century length time scales. And since we have proven 400 PPM is beneficial, we only have to worry about getting back to 400 PPM if we run into problems..

      We are proving that higher levels of CO2 are beneficial and claims of harm were wrong by achieving higher levels of CO2 and observing the result.

  73. The view of Australia’s Reserve Bank governor Glenn Stevens is in line with those of us posting here for a focus on growing our economic capacity as a means of dealing with the future (and the present). Yesterday Stevens warned there was a danger slow economic growth since the global financial crisis might become permanent and the country needed a commitment to reforms that would lift the economy’s potential. … “I would suggest that the case for reform needs to be presented as a positive narrative for economic growth. We all know that competitive markets, investment in education, skills and infrastructure and adaptability are key parts of that growth narrative.”

    Not only should reform make it easier for capital and labour to be deployed where they are most -valued, he said, but it should also foster entrepreneurship and innovation. He said he was not just -arguing the case of economic growth “for the sake of it”.

    “Our collective ability to lift ¬social policy outcomes, to enjoy the benefits of a ‘good society’ or at a more basic level to provide public services and even to defend ourselves, ultimately rests on a productive economy,” he said. “Many problems, including distributional ones, are easier to deal with if per-capita incomes are rising steadily, less so if they are stagnant.”
    Mr Stevens said he was not pushing for growth “at any price”, saying the reason wealthy countries had cleaner air and water, better health and education systems and higher standards for environmental protection was because the business sector was so productive.

    “They have higher wages, not because they decree wages shall be high but because well-educated, skilled workforces working with a lot of capital and modern technology are more productive,” he said.

    – Australia has had several good RBA heads. I’ll exclude Ian MacFarlane, who abused me more than 20 years ago when I disputed his claim that “the protection debate was over” in Australia. I hope that he has noted the heavily-protectionist thrust of recent ALP policy, which threatens the completion of a free trade agreement with China which has been te years ikn the making.

    http://www.theaustralian.com.au/business/economics/rba-governor-glenn-stevens-economy-risks-living-standards/story-e6frg926-1227453219617

    Faustino

  74. “We know that climate change is a problem – but how big a problem is it?”

    How do we know that? I’m not aware of anyone having established that the null hypothesis is invalidated. Null hypothesis being that the warming is natural variability.

    A simple model of steady warming coming out of the little ice age with a sine wave explains temperatures over the last 2 centuries better than the CAGW argument. So I don’t “know” that anyone has made a serious argument which employs the normal tools of logic that establishes that global warming is even a problem at all.

    When did logic stop mattering in science?

  75. blueice2hotsea

    Judith-
    Thanks for this interesting post. I am disappointed that denizen philosophers such as Mosher and willard did not weigh in with a more intelligible elaboration on their objection to your conclusions re: Betz and Nic Lewis. (e.g. willard July 20, 2015 at 7:25 pm.

    I don’t understand where your conclusions are not supported by Betz paper.

    [Beta argues] that modal falsification is the correct methodology for preparing scientific climate policy advice.

    Betz says it is immoral, irresponsible, irrelevant and impossible to inform policy using GCMs in their current modal inductivist formulation.

    The bolded epitaphs also apply to ‘informing’ policy via any climate sensitivity methodology which relies upon [subjective], arbitrary and/or GCM derived Bayesian priors.

    Since Nic Lewis approach uses objective Bayesian priors, the implication, per Betz, is that it is not impossible to inform climate science policy using both Lewis’ approach (and observations).

  76. Pingback: EPA’s Climate Action Flimflam Report, Part 2

  77. Berényi Péter

    The ‘worst scenario’ for climate change is clearly a VEI-8 volcanic eruption in the tropics, followed by steep cooling and a decade of crop failures worldwide, leading to a mega famine, claiming billions. With no luck resurgence of large Northern continental ice sheets would follow, making most of the developed world uninhabitable indefinitely.

  78. Pingback: » Dot Earth Blog: Whiplash Warning When Climate Science is Publicized Before Peer Review and Publication

  79. The Hansen paper is now available. Enjoy. As someone quoted Trenberth saying, it is a what-if type of paper that looks at scenarios of quick glacier melting and its impacts. This shuts down the AMO, and could make the LIA look like nothing for Europe, and it happens in this century, according to some of those graphs. Those more worried about the cold, this one is for you, and you get sea level rise with it as a double whammy.
    http://www.atmos-chem-phys-discuss.net/15/20059/2015/acpd-15-20059-2015.pdf

  80. Warning: relearning ahead!

    Let’s begin with your “Risk Assessment” paper:
    “There is a new report out, entitled Climate Change: A Risk Assessment. IMO this is far and away the best risk assessment for AGW that I have seen. That said, it is far from perfect, for reasons described towards the end of the post (largely associated with how much warming we can expect, which is obviously the key issue). But IMO it has appropriately framed the climate risk assessment problem, and its authors (for the most part) don’t seem to have any obvious agenda beyond . . . risk assessment.”

    I simply disagree for many reasons, not because of warming to expect. That I can tell you now: do not experct any greenhouse warming at all. The authors are so thoroughly inculcated to be true believers that they really don’t think they are advocating global warming doctrine – it is just natural to them. Perhaps you too if you think they have n\o obvious agenda in their talk. To make sense of risks involved there are two scientific considerations in the foreground. The first one is existence of the hiatuses, the stoppages of warming in the twentieth and twenty-first centuries. Stoppage while carbon dioxide is increasing, that is. The second one is the fact that existence of a hiatus is incompatible with existence of the greenhouse effect. If there is a hiatus there is no greenhouse effect. And if there is a greenhouse effect rhere is no hiatus. But the Arrhenius greenhouse theory used by the IPCC is predicting warming nevertheless during the hiatus. That makes it plain wrong and it has inspired dozens of papers to show that it is true. Arrhenius must be replaced by MGT, the Miskolczi greenhouse theory [3],[4] that correctly predicts temperature. An additional problem here is that the hiatus in the eighties and nineties was over-written by a fake so-called “late twentieth century warming” by people who issue global temperature charts. That is scientific fraud they have gotten aqway with for years: since 1979 to be precise.. I first spotted this in HadCRUT3 [5] while doing research for my book “What Warming?” [1]. In 1979 their data were lined up exactly with satellite data but over the rest of the century theirs kept crawling up relatve to satellites and swamping the hiatus until in the next century it was a tenth of a degree above it. I later discovered that HadCRUT, GISS and NCDC were all involved in this fraud. They show signs of computer processing consisting of numerous sharp spikes in exactly the same locations. This guarantees that the exact same computer program was used by all three. Logic leads to the coverup becauese the computer footprints go back to 1979, the start of the hiatus. The hiatus itself is shown as figure 15 in my book. Fortunately they still do not control satellites and that is where I got these data from. Anyone can still download the original data for the hiatus of the eighties and nineties if they want to. During the eighties and nineties ENSO was active and produced a wave train of five El Ninos, with La Nina valleys in between, in the middle of the hiatus. Putting a dot at the midpoint between an El Nino peak and its neighboring La Nina valley locates the global mean temperature for that time slot. Figure 15 shows this. If you do this to all five El Ninos these dots line up in a horizontal straight line that indicates no warming for an 18 year period. This makes this hiatus exactly like the present day hiatus – carbon dioxide keeps increasing but temperature stays the same. Dozens of papers have been written to prove that the present hiatus does not exist. The latest attempt is by Karl et al. They base their argument on a new water temperature measurement, ERSST v.4, unearthed by NOAA for this occasion. This newly created NOAA product is said to incorporate 11 improvements and appears to be set up to be impossdible to check. It must be considered to be a fake for this reason and for its difference from RSS satellites that do not show that warming. Checking the Karl paper further indicates that of all the data they used, only two data points show warming sufficient to compete with the hiatus. Furthermore, if you claim that warming exists you must show a temperature graph to prove it. They did not. Since the hiatus of the eighties and nineties was hidden from the bulk of reaerchers, those trying to prove the absence of hiatus did not get a chance to attack it. This is just as well because this particular hiatus is self-calibrating thanks to the ENSO wave train in the middle of it. It is of course much harder for denialists to prove the absence of two hiatuses than the absence of one ythey thought they sere dealing with. The absence of warming despite an increase of atmospheric carbon dioxide has mystified all so-called “climate experts.” That is understandable because they simply could not believe that they had been so wrong, so long. Namely inbelieving that Hansen observed the greenhouse effect in 1988 as he claimed. Hansen was wrong because his hundred year warming curve he used as proof was wrong. What the presence of hiatuses means is that the greenhouse effect, promulgated by Hansen and others, is simply a myth. Arrhenius first proposed it in 1896 and over the years it became part of the global warming doctrine. Its prediction that adding carbon dioxide to the atmosphere will warm the air does not apply to the hiatus, A scientific theory that makes wrong predictions is considered invalid and belongs in the waste basket of history. That is where the Arrhenius theory belongs. A theory that does correctly predicts what we do observe is MGT, the Miskolczi greenhouse theory. It differs from Arrhenius in being able to handle more than one greenhouse gas at the same time. According to MGT, carbon dioxide and water vapor that are both greenhouse gases form a joint optimum absorption window in the infrared whose optical thickness is 1.87. The latter is obtained from the analysis of radiosonde data. If you now add carbon dioxide to the atmosphere it will start to absrb in the IR, just as Arrhenius says. But this increases the optical thickness. And as soon as this happens, water vapor will begin to diminish and rain out, the original optical tghickness is restored, and no Arrhenius warming takes place. This is precisely what we observe during today’s hiatus. It solves the mystery of the missing heat: it did not dive down into the ocean bottom but left the atmosphere for outer space. All those fifty-odd papers that did not chose outer space as the destination are simply wrong. This is opf course is not the same missing heat as as Trenberth’s. He found that after introducing thousands of Argo buoys eighty percent of the global heat was missing. If I had been the reviewer I would have sent him back to study the Argo buoys instead of publishing nonsense. It may not be too late for him, who knows. Finally we need to look at the overall picture of multiple hiatuses. The two hiatuses together block out warming from eighty percent of the satellite era that starts in 1979. Thevremaining twenty percent are taken up by the super El Nino of 1998 and a short warming starting in 1999. It is the only warming during the entire satellite era. In three years it raised the twenty-first century temperature by a third of a degree Celsius and then stopped. There was no further warming but Hansen took advantage of the first decade of the twenty-first being higher than the twentieth and pronounced it the work of carbon dioxide greenhouse warming. There is no sight of any greenhouse warming there and we can pronounce the entire satellite era as being greenhouse free. With it dies AGW. This means that we are dealing with two platforms with no warming that are attached to one another by a short but strong step warming. This pattern would make me look for a similar pattern, possibly involving a hiatus from the fifties to the mid-seventies biit I chose to leave it alone because of numerous changes that have taken place there. As it is now, it can be argued that the normal state of global temperature is a series of hiatuses connected by short step warmings, up or down. I would assume the two hiatuses I have described are real fearures of the global temperature and start redrawing a new global temperature curve based on that. As to that “Risk Assessment” swtory, it is simply trash. How bad is that? In their policy brief they make three points. Point 1: What are we doing to the climate?—emitting greenhouse gases. Point 2: What could climate change do to us?—Sea level will not fall down—Small changes of climate will have large effects—food will not be secure—heat can be fatal even when lying down in the shade. Point 3: What might we do to each other?—Risk to national and internatioinal security—State failures might rise. So what do they suggest? [1] Assess risks of climate change as you would national security or public health problems. [2] Involve a wide range of experts including military strategists. [3] Report risk assessments to the highest level of government. This grab-bag of cpmplaints does not deserve any comment. It is unbelievable however that mitigation procedures applied world wide cost an estimated one billion dollars a day to protect us from such irrelevancies. I take it that the authors have no objections to any of this, including the price tag for mitigation. How can you really say that they have no “… obvious agenda beyond . . . risk assessment.”
    *********************************************************
    [1] Arno Arrak, “What Warming?” (Createspace 2010)
    [2] Thomas R. Karl met al, “Possible artifacts of data bases in the ecent global warming hiatus” – Sciencexpress 4 June 2015/Page 1
    [3] Ferenc M. Miskolczi, “Greenhouse effect in semi-transparent planetary atmospheres” Idöjárás, 111, 1(2007) 1-40

    • Additional references

      [4] Ferenc M. Miskolczi, “The stable stationary value of the earth’s global average atmospheric Planck-weighted greenhouse-gas optical thickness” Energy and Environment 21, 4 (2010) 243-252

      [5] Arno Arrak, op. cit., figure 24

      • Joel Williams | July 24, 2015 at 5:52 pm | “Arno, got a URL that will show your Figure 15 just by itself?” Sorry, Joel, it is a book. Spring for it, Amazon has it. It has other goodies that contradict IPCC on things like volcanic cooling and Arctic warming that you should find useful. Or give me an email address to send an updated version.

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  82. Arno, got a URL that will show your Figure 15 just by itself?

  83. Reblogged this on Climate Collections and commented:
    Dr. Judith Curry discusses a process for climate change risk assessment.

    [Executive Summary] JC conclusions

    I think the new Climate Change Risk Assessment document is an important step forward in framing how we should approach climate change risk assessment. The appropriate focus is the plausible worst case scenario, which has not been a focus of the IPCC or climate establishment. Instead they have focused on a mean, a likely range, or an alarming possibility.

    I have proposed scenario falsification as a way to proceed, in terms of identifying plausible versus possible scenarios. I hope that risk assessors, philosophers and climate scientists can work together and shift their focus to scientifically robust and policy useful strategies for assessing the plausible worst case scenario for human caused global warming.

  84. Judy,

    The fact that a plausible worst case scenario can not be known is part of the uncertainty that has to be built into risk – not something to dismiss or lessen risk, but – when a several million year change to basic long term atmospheric energy capture has been effected, with obvious attendent changing energy accumulation and key earth systems impact – as an addition to it, as with any other kind of risk where relevant. Consider. (If you think any of this is unfair or incorrectly characterizes the issue, although obviously I take great issue with the way this issue at least in the past has been strategically assessed here, let me know I’ll try to add what I think is fair.)

    In other words, we don’t know what the upper limits are, and there is no way to have an idea of which assessments are “good” and which aren’t until after the fact, so simply incorporate Hansen’s assessments into the risk range, as they already should have been since faster sea level rise than expected (as difficult as the time frame is to pintpoint, given the non linear and somewhat unpredictable nature of exactly what type of shifting and how fast it will occur will take place), is within the range of realistic probability.

    To say it is not when models vastly underestimated ice sheet melt rates and acceleration barely over a decade ago, and despite cherry picking attempts to argue otherwise here, more energy has gone into ice sheets, glaciers and the oceans than originally thought, and while it is hard to pinpoint a time frame, Greenland melting – bad for us – is not geologically that big of a deal (not even taking into account the ice sheet acceleration in West Antarctica, the recent and sudden destabilization of the peninsula and signs of the middle and the end on Larsen C and B, nor now known net melt and acceleration in East antarctica, nor the wild and still vastly underestimated issue of warming ocean columns and major early spiking arctic methane indicia of potentially massive and self amplifying net methane increases and risk ranges indicated, and potent effect of methane – versus common and much lower 100 year timescale GWPe projection practices – if levels continue to rise, is simply to let belief or desire drive assessment, or not fully comprehend the vast geological scope, non linear nature, man centric (“expectation of stability”) orientiation bias, and uncertainty aspects of this issue.

    -‘Carter

    P.s I don’t mean to take such issue with you in the first link above but you give Congressional testimony and as have many have gotten a lot of very fundamental things wrong. Which is fine, and everyone does to some extent; but the issue is – can adjustments based on increased knowledge rather than self reverberating reinforcing “skeptic” solidarity echo chambers and general science castigation be made, or does the process of perpetual reinforcement of already arrived at beliefs and dismissal of conflicting analysis and facts continue?

    Believe it or not I appreciate your concern for the issue, as well as the always constant worry of groupthink. (That worry does not mean that a modern day conservatively arrived at large majority scientific opinion on an issue that arose due to observation of the phenomenon – not because an assessment yea or nay had to initially be made as on most issues and forcing a much higher mistake pattern – is not generally right.) I just wish the unfair and one sided inflammation, and some of the correctable mistakes and extreme one side of the range cherry picking could be greatly tempered.

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