by Judith Curry
The National Academies has published a new report: Attribution of extreme weather events in the context of climate change.
The authors of the report are:
- DAVID W. TITLEY (Chair), Pennsylvania State University
- GABRIELE HEGERL, University of Edinburgh, UK
- KATHARINE L. JACOBS, University of Arizona, Tucson
- PHILIP W. MOTE, Oregon State University, Corvallis
- CHRISTOPHER J. PACIOREK, University of California, Berkeley
- J. MARSHALL SHEPHERD, University of Georgia, Athens
- THEODORE G. SHEPHERD, University of Reading, UK
- ADAM H. SOBEL, Columbia University, New York, NY
- JOHN WALSH, University of Alaska, Fairbanks
- FRANCIS W. ZWIERS, University of Victoria, BC, Canada
This paragraph from the Concluding Remarks of the Summary provides a good overview:
In the past, a typical climate scientist’s response to questions about climate change’s role in any given extreme weather event was “we cannot attribute any single event to climate change.” The science has advanced to the point that this is no longer true as an unqualified blanket statement. In many cases, it is now often possible to make and defend quantitative statements about the extent to which human-induced climate change (or another causal factor, such as a specific mode of natural variability) has influenced either the magnitude or the probability of occurrence of specific types of events or event classes. The science behind such statements has advanced a great deal in recent years and is still evolving rapidly.
Key points from the 14 page summary:
Event attribution is more reliable when based on sound physical principles, consistent evidence from observations, and numerical models that can replicate the event.
Confidence in attribution findings of anthropogenic influence is greatest for those extreme events that are related to an aspect of temperature, such as the observed long-term warming of the regional or global climate, where there is little doubt that human activities have caused an observed change
Confidence in attribution analyses of specific extreme events is highest for extreme heat and cold events, followed by hydrological drought and heavy precipitation. There is little or no confidence in the attribution of severe convective storms and extratropical cyclones.
Attribution of events to anthropogenic climate change may be complicated by low-frequency natural variability, which influences the frequencies of extreme events on decadal to multidecadal timescales.
A definitive answer to the commonly asked question of whether climate change “caused” a particular event to occur cannot usually be provided in a deterministic sense because natural variability almost always plays a role.
Attribution studies of individual events should not be used to draw general conclusions about the impact of climate change on extreme events as a whole.
Unambiguous interpretation of an event attribution study is possible only when the assumptions and choices that were made in conducting the study are clearly stated and uncertainties are carefully estimated.
Bringing multiple scientifically appropriate approaches together, including multiple models and multiple studies helps distinguish results that are robust from those that are much more sensitive to how the question is posed and the approach taken
A focused effort to improve understanding of specific aspects of weather and climate extremes could improve the ability to perform extreme event attribution.
The most illuminating part of the report is the key recommendations:
In particular, this committee recommends research that aims to improve event attribution capabilities, which includes increasing the understanding of:
- the role of dynamics and thermodynamics in the development of extreme events;
- the model characteristics that are required to reliably reproduce extreme events of different types and scales;
- changes in natural variability, including the interplay between a changing climate and natural variability, and characterization of the skill of models to represent low frequency natural variability in regional climate phenomena and circulation;
- the various sources of uncertainty that arise from the use of models in event attribution;
- how different levels of conditioning (i.e., the process of limiting an attribution analysis to particular types of weather or climate situations) lead to apparently different results when studying the same event;
- the statistical methods used for event attribution, objective criteria for event selection, and development of event attribution evaluation methods;
- the effects of non-climate causes—such as changes in the built environment (e.g., increasing area of urban impervious surfaces and heat island effects, land cover changes), natural resource management practices (e.g., fire suppression), coastal and river management (e.g., dredging, seawalls), agricultural practices (e.g., tile drainage), and other human activities—in determining the impacts of an extreme event;
- expected trends in future extreme events to help inform adaptation or mitigation strategies (e.g., calculating changes in return periods to show how the risk from extreme events may change in the future);
- the representation of a counterfactual world that reliably characterizes the probability, magnitude, and circumstances of events in the absence of human influence on climate.
Event attribution capabilities would be improved with better observational records, both near-real time and for historical context. Long homogeneous observed records are essential for placing events into a historical context and evaluating to what extent climate models reliably simulate the effect of decadal climate variability on extremes.
Statements from the authors
The Carbon Brief provides a good overview of the study and interviewed a number of scientists that authored the report and others who were not authors but who have conducted research on this topic.
Heidi Cullen’s NYTimes op-ed, excerpts:
One view holds that no single storm or drought can be linked to climate change. The other argues that all such things are, in some sense, “caused” by climate change, because we have fundamentally altered the global climate and all the weather in it.
While true, this “all in” philosophy doesn’t adequately emphasize the fact that not all of the extreme weather we experience today has changed significantly. Some of it is just, well, the weather.
But some of our weather has changed significantly, and now a new report from the National Academies of Sciences, Engineering and Medicine has outlined a rigorous, defensible, science-based system of extreme weather attribution to determine which events are tied to climate change.
Like the surgeon general’s 1964 report connecting smoking to lung cancer, the report from the National Academies connects global warming to the increased risk and severity of certain classes of extreme weather, including some heat waves, floods and drought.
This is an important development. Climate change can no longer be viewed as a distant threat that may disrupt the lives of our grandchildren, but one that may be singled out as a factor, possibly a critical factor, in the storm that flooded your house last week. The science of extreme weather attribution brings climate change to our doorsteps.
And sometimes it is easier to blame climate change than acknowledge inaction in the face of factors unrelated to the weather. For example, in a severe drought plaguing southeastern Brazil — including São Paulo, with a surrounding metropolitan population of about 20 million — some were quick to blame global warming. But in analyzing the underlying causes of this drought, my colleagues and I found, in a study published last year, that climate change was not a major influence. Instead, population growth, increasing water consumption and leaky pipes were the real culprits.
From Adam Sobel’s WaPo editorial: Dr. Sobel
Though attribution science is advancing quickly, it’s still new, and some scientists are uneasy about it. Some are concerned that it politicizes weather disasters by making them into climate change stories. I have been concerned, on the other hand, that stories focused on attribution in the wake of weather disasters can send misleadingly skeptical messages about climate change as a whole.
So media coverage of attribution studies sometimes ends up focusing more on what we don’t know than what we do. That can leave the impression that we know less than we really do, which is unhelpful in a political climate which already doesn’t take the real one seriously enough.
But attribution studies help to close the gap between the widespread notion of climate change as distant and the real need for us to act on it now. Real extreme weather events get people’s attention. Sometimes, some of that attention lands on broader issues around climate change that are overdue for it.
Ted Shepherd
Co-author Ted Shepherd has just published a very nice paper A common framework for extreme event attribution. From the conclusions:
In climate science, we are accustomed to strive for quantitative answers, but it is important to appreciate that being quantitative is not necessarily the same thing as being rigorous. In particular, it is essential to distinguish between quantifiable uncertainty and Knightian (i.e. deep) uncertainty. Uncertainty associated with sampling variance is quantifiable, e.g. through boot-strapping methods, but many of the uncertainties associated with climate change—especially the deep uncertainties associated with the atmospheric circulation response to climate change—are not easily quantifiable. Examining the sensitivity of a result to the choice of climate model, as is becoming common practice in risk-based ap- proaches, is an important first step in determining robustness. However, model spread is not a quantification of model uncertainty because a multi-model ensemble does not represent a meaningful probability distribution. It has therefore been argued that the quest for more accurate climate model predictions is illusory and that instead we need to be using models for understanding, not prediction.
JC reflections
While this report contains no surprises or new assessments, it is more cautious about extreme event attribution than is Myles Allen [link]. That said, I remain highly critical of efforts to attribute extreme weather events to human caused climate change.
I have written many previous blog posts on this topic [link]. Detection and attribution of extreme weather events requires:
- a very long time series of historical observations of the extreme event at a particular location (which is rarely available)
- an understanding of the variability of extreme weather events associated with multi-decadal ocean oscillations (which requires at least a century of observations)
- climate models that accurately simulate both natural internal variability on timescales of years to centuries and the extreme weather events (a pipe dream; we are not even close)
IMO the best, and most important, paper on extreme event attribution is a paper by Hall et al. [discussed previously at this link]. This paper by Hall et al. is not even referenced in the new National Academies report.
And finally, I find nothing in this report that convinces me that extreme event attribution is feasible. The most plausible attribution is for heat waves; however the recent Sardeshmukh paper [link] finds that the intuitively reasonable attribution of more heat waves to a higher average temperature doesn’t work in most land regions.
I will repeat my summary from a previous post:
Not sure what the motive is for the attribution of extreme events, other than to build political will for climate change policies. More comprehensive analysis of regional extreme events (including those in the paleo records, of which we need more of) in the context of known modes of natural climate variability is probably the single most useful thing that could be done in this regard.
Did they provide an example(s) of where a given weather event can be said to be largely due to climate change?
yes they provided a number of examples
ho hum. they still can’t pin it on CO2.More science waffle that fails to conv ince any reasonable mind that attribution from anthropogenic origins causes extreme events.
People need somebody to blame.
Rather than imply a large group of scientists had impure motives, why not consider the possibility the public has noticed severe weather and is asking whether it’s related to climate change?
Weather isn’t more severe. The perception severity has worsened is a delusion that proper science should discourage, and prevent mistaken public policy to a non-existent problem.
Who to blame? Where should I start?
How to repair? Mebbe Acme has a gizmo.
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Is this how you read this article? Imply .. impure .. conspire ..
Max
You mean those 20 year olds concluding they have never seen so much extreme weather in their entire lives and it absolutely must be AGW?
Why don’t we ask the million year old man.
why not ask yours truly the seventy six year old man? I can assure you-all that there has been no appreciable climate change in this part of rural Virginia in the past thirty five years. We’re right where we were back in the 1980s; some days hot some cold; some days wet some dry; some stormy some gentle; cold winters, warm winters, hot summers, cool summers – we get it all. We call it “weather”.
FWIW according to records the temperatures are no warmer (and in fact recently are much cooler) than in the 1930s. People keep using those words “climate change” – when does it start do you think?
Ak,
Disagree. Weather events grab peoples attention and can have significant impacts to their lives. The MSM knows this, which is why they love it. They know few things draw in more viewers.
Intelligent people not pursuing an agenda understand the interest, but also know “it’s just weather”. People just as intelligent who have an agenda understand that the more they can get people thinking weather and climate change are the same coin is effectively seizing the only high ground left. You can be losing ground and see that the battle is at risk of being lost, but if you can rally on the last piece of significant terrain, victory is still possible.
That is what I think this paper is. Kind of ironic that the folks who used to tell us that weather is not climate are now pinning their hopes on convincing us it is.
Cognitive dissonance Ho! It is rife in this ‘Wicked Problem’.
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It would have to be COLDER than normal, for a sustained period, for people to realize the warm events were a blessing! COMING SOON TO A BIOSPHERE NEAR YOU!
My gawd you guys can get mixed up.
The default view in the public is now that everything is attributable to climate change, for example the Louisiana floods, so it helps when scientists can sort out which ones are and which are not. You should welcome this compared to the situations where the scientists say nothing and leave the public to just jump to the simplest conclusion every time there is another extreme.
“The public” jumped to this conclusion?
Wow. Who gave them that idea I wonder…
Among others, a shaman who dropped out of Divinity School but not before the lessons in manipulation of the masses by primitive religious leaders using fear and guilt about the weather.
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James Hansen, February 2012.
> scientists can sort out which ones are and which are not
No, they can’t. They just say they can
Predictability is the key to real science. Predicting there will be flooding somewhere sometime is just flabbily dishonest
opluso,
Taking my cue from max10k, I have changed your quote to something I believe, as follows –
“Imagine a giant asteroid NOT on a direct collision course with Earth. That is the equivalent of what we face now [with climate change], yet we dither.”
I believe what I wrote, therefore it is become truth. Therefore dithering, or as non Warmists would put it, pursuing more useful pursuits than chasing unicorns, seems to be quite reasonable.
I’m happy enough to let the Warmists worry on my behalf, but not concerned enough to pay them to do it. The same applies to pursuing unicorns – pursue away, but don’t expect me to fund your fantasy. Maybe max10k will contribute on my behalf.
Cheers.
ianl8888 said:
I was wondering about that too.
Ted Shepherd, one of the coauthors, in the passage provided above in JC’s post says:
So if what these guys do can’t predict, then is it still science?
It seems to me it would no longer fit the definition of what Modernism considers science to be, but would fit Hume’s definition of science, or Kant’s at best.
The report is downloadable for free from PNAS. Judith gave the link. I have not read the study yet but I want to carefully look at how they went from data selection, data analysis, statistical based conclusion on correlation and finally to strong or definitive conclusion of cause and effect. I would be very surprised if they then draw the conclusion that manmade greenhouse gases are “the cause” since that requires bringing in the IPCC criteria for attribution based on Delphi opinion polling of internal senior editors of the AR reports stating “… 95+% sure that anthropogenic greenhouse gases, notably CO2 is the primary cause of global warming.
While we cannot say with complete certainty that this latest attribution bunk is the direct result of Publish-or-Perish, its emergence is consistent with forecasts which suggest that such regurgitations will become more frequent and more intense under Publish-or-Perish during what some researchers (mosomoso et al, 2016) are now calling the Dogmatocene.
Dogmatocene. Plus many. May your down under bamboo prosper. Also your Aussie coal, which Japan and Korea now need more of.
> … Japan and Korea now need more of
Yes, but our politics has become far more filled with sovereign risk from green propaganda. Enough city-based people believe the nonsense to force politicians to dissemble, throw 180’s, defer, delay and make up new rules on the fly
I’ve long given up. People deserve exactly what they get
Attributions abound in the liter-a-chure :
‘Anthropocene,’ Revkin et Big Al,1992,
‘Idiocene,’ bts et al, 2015, ‘Dogmatocene,’
mosomoso al, 2016… Watt next?
Drongocene coming, along with Peak Adult. (In England the Drongocene will be known as the Blackout.)
I liked ‘Bryony Blackout’, but she fades into the mist of earlier, uglier, times.
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Sometimes the simple answer is the correct one.
To better understand.
Adm. Titley has gone all in for the dark side. So, SREX is invalid four years later, after climate models have been falsified with 4 more years of ‘pause’?
Have not yet read the paper, so apologies if an initial incredulous kneejerk to more warmunist spam. Their growing desperation is palpable.
Yeah yeah yeah we know Rud, these authors are warmunists and they are conspiring to promote fiction and fool anyone who will listen. I would call such behavior sociopathic, but that might just be me.
Admiral Titley, who lives down the hall, and serves as if constantly recollecting that moral idiocy is a duty.
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Joseph, I seldom reply to your ilk. BUT. This paper now says SREX is wrong. It says extreme weather fingerprints can be distinguished by climate models that can neither be validated globaly (pause) nor regionally downscaled (essay Last Cup of Coffee is one example). So pardon my skepticism from first principles.
I am not on firemans watch to definitively debunk every warmunist emanation 24/7 to your satisfaction. But you had better hope I never am, cause would not end well for you and yours. Based on high scores so far.
I don’t know if the conclusion drawn are right or wrong. Follow-up papers could point out any errors. So I am skeptical of every paper too. But you go on and on about warmunists as though almost every paper is part some overarching plot . It’s bit tiresome an I think misleading.
No plot, merely an extraordinary popular delusion and a madness of the herd. There are those who breathed and bellowed together, who clashed and bashed their horns together in panic; they know who they are.
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So now they are so deluded they don’t even know what they or doing saying is wrong. But it’s so obvious to Kim.
Rud
Weather “Fingerprints”? Sounds like a tribute to HegerL!
Richard
The alarm was the madness, Joe. Consequences of man’s release of CO2 have been, are, and will continue to be net beneficial, as our descendents will well realize.
The alarm has essentially passed, peaking nearly a decade ago. We still hear the horrific echoes of the screaming and roaring from then, and we can see and hear yet some very frightened individuals, yet bellowing. The young of the heard will suffer post traumatic stress disorder from the panic for the rest of their years, ameliorating, I hope, with time.
Not so hard to see. Just look around a bit, you can’t get it from the newspaper.
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It is you Joseph.
I can only hope this religion of yours provides padded benches to kneel on.
And I did want to know if this is what your believe?
I believe that any conspiring know it; far more are merely keeping in step and in line.
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Like bunch of puppets go through the motions maybe..
Bits of clay, strutting their petty parts across the stage,
Shot like a rabbit in a run, cantering now, it’s all the rage.
===============
Joseph, deniers identify themselves as skeptics to establish credibility, and then lose it by opening their mouths.
The climate models have never been validated so let’s leap to extreme events. “Look at this new shiny object over here!”
This new paper appears to be the result of Kevni Trenberth’s effort to reverse the null hypothesis and put the burden of proof on researchers who claim an event was within the boundaries of natural variability, Much of the language is exactly what Trenberth has been pounding home after every extreme event. I fear Trenberth and is ilk are taking science back to the Dark Ages as I wrote here http://landscapesandcycles.net/trenberth-s-claim-that-warming-increases-snowfall.html and here http://landscapesandcycles.net/trenberth-reverses-null-hypothesis-for-droughts.html
From the publication’s description: “As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe.” This is something that can be observed from the records and, if true, trivially easy to demonstrate. That is, if the instruments used a hundred years ago to measure precipitation and surge levels and wind speed were as reliable then as the ones we use today – and if they were as extensively employed. I suspect the storms that we experience today seem stronger to us than ones endured by others years ago by people long dead.
JC gave a very insightful lecture where she addressed this empirical claim.
https://www.youtube.com/watch?v=D4AAN0H8MRg
For those who haven’t seen the lecture, I highly recommend it.
What I took away from JC’s lecture is that these empirical claims are very much in dispute.
http://i.imgur.com/WizJFY3.png
http://i.imgur.com/nW3yhkN.png
http://i.imgur.com/rDiqJaX.png
http://i.imgur.com/vlZYDrC.png
http://i.imgur.com/8jdq59s.png
http://i.imgur.com/0Gxtovw.png
The problem with coming to any agreement as to what should be done is that there are two very different philosophies of science involved, and several different moral priorities which often conflict with each other.
http://i.imgur.com/CO37kC5.png
http://i.imgur.com/oNHMmo8.png
Judith said “I have written many previous blog posts on this topic [link]. Detection and attribution of extreme weather events requires:
a very long time series of historical observations of the extreme event at a particular location (which is rarely available)
an understanding of the variability of extreme weather events associated with multi-decadal ocean oscillations (which requires at least a century of observations)
climate models that accurately simulate both natural internal variability on timescales of years to centuries and the extreme weather events (a pipe dream; we are not even close)
IMO the best, and most important, paper on extreme event attribution is a paper by Hall et al. [discussed previously at this link]. This paper by Hall et al. is not even referenced in the new National Academies report.”
While this statement refers to extreme weather events only, I believe that it applies to climate change trend analyses in general and that this position is the only tenable position to take by climate scientists.
I really do not get it. At all.
The Holocene Epoch is, as of this year, 11,719 years old (+/-99 years).
http://epic.awi.de/12532/1/Ras2005a.pdf
My question here is simply this: How in the world (meaning on earth), are you (meaning us, we etc.) going to be able to tell anthropogenic extreme weather events from the regularly scheduled extreme weather events that typically attend the end extreme interglacials?
To wit:
“In order to estimate how long it will be before the present period of interglacial warmth comes to an end, we first have to estimate how long previous periods of extreme warmth lasted. Our best indicator is 180 records in benthic foraminifera. In these records, the periods of extreme warmth appear to be roughly one half of a precession cycle (i.e., “‘ 11,000 yr) in duration.” http://www.personal.kent.edu/~jortiz/paleoceanography/broecker.pdf
The precession cycle varies between 19-23kyrs and we are at the 23kyr point now, making 11,500 half. Of the 8 interglacials since the Mid Pleistocene Transition only 1 has lasted longer than about half a precession cycle (MIS-11).
“The geology of the Last Interglaciation (sensu stricto, marine isotope substage (MIS) 5e) in the Bahamas records the nature of sea level and climate change. After a period of quasi-stability for most of the interglaciation, during which reefs grew to +2.5 m, sea level rose rapidly at the end of the period, incising notches in older limestone. After brief stillstands at +6 and perhaps +8.5 m, sea level fell with apparent speed to the MIS 5d lowstand and much cooler climatic conditions. It was during this regression from the MIS 5e highstand that the North Atlantic suffered an oceanographic ‘‘reorganization’’ about 11873 ka ago. During this same interval, massive dune-building greatly enlarged the Bahama Islands. Giant waves reshaped exposed lowlands into chevron-shaped beach ridges, ran up on older coastal ridges, and also broke off and threw megaboulders onto and over 20 m-high cliffs. The oolitic rocks recording these features yield concordant whole-rock amino acid ratios across the archipelago. Whether or not the Last Interglaciation serves as an appropriate analog for our ‘‘greenhouse’’ world, it nonetheless reveals the intricate details of climatic transitions between warm interglaciations and near glacial conditions.”
“Rapid changes in sea level and associated destabilization of climate at the turbulent close of the last interglacial maximum appear to be recorded directly in the geomorphology, stratigraphy, and sedimentary structures of carbonate platform islands in the Bahamas. Considered together, the observations presented here suggest a rapid rise, short crest, and rapid fall of sea level at the close of 5e.”
“The lesson from the last interglacial “greenhouse” in the Bahamas is that the closing of that interval brought sea-level changes that were rapid and extreme. This has prompted the remark that between the greenhouse and the icehouse lies a climatic “madhouse”! http://www.researchgate.net/publication/249518169_Rapid_sea-level_changes_at_the_close_of_the_last_interglacial_(substage_5e)_recorded_in_Bahamian_island_geology/file/9c96051c6e66749912.pdf
“Here we focus on the final events of substage 5e. After the building of reef crests up to circa +2 m, sea level rose rapidly to at least +6 m toward the end of the interglaciation, cutting coastal notches and flooding interior areas (Neumann and Hearty, 1996). During the fall of sea level from the 5e maximum, large areas of the Bahamas were reshaped by sedimentary processes. As lagoons shallowed and beaches widened, dunes grew so rapidly that standing trees became entombed in sand (Neumann and Hearty, 1996). Along cliffed coasts during the same interval, giant boulders were catapulted landward as far as 0.5 km by the action of large waves (Hearty, 1997). On low-lying areas of the Bahamas, extensive V-shaped stormbeach ridges (“chevrons” in this paper) were emplaced by similar, high-energy events. The origin of these storm ridges, associated run-up features, and boulder deposits, plus the implications for climate history at the close of the last interglaciation, are the subjects of this paper.”
https://www.uow.edu.au/content/groups/public/@web/@sci/@eesc/documents/doc/uow014952.pdf
Some of the more chilling words you may read on climate change were published by Boettger, et al (Quaternary International 207 [2009] 137–144):
“In terrestrial records from Central and Eastern Europe the end of the Last Interglacial seems to be characterized by evident climatic and environmental instabilities recorded by geochemical and vegetation indicators. The transition (MIS 5e/5d) from the Last Interglacial (Eemian, Mikulino) to the Early Last Glacial (Early Weichselian, Early Valdai) is marked by at least two warming events as observed in geochemical data on the lake sediment profiles of Central (Gro¨bern, Neumark–Nord, Klinge) and of Eastern Europe (Ples). Results of palynological studies of all these sequences indicate simultaneously a strong increase of environmental oscillations during the very end of the Last Interglacial and the beginning of the Last Glaciation. This paper discusses possible correlations of these events between regions in Central and Eastern Europe. The pronounced climate and environment instability during the interglacial/glacial transition could be consistent with the assumption that it is about a natural phenomenon, characteristic for transitional stages. Taking into consideration that currently observed ‘‘human-induced’’ global warming coincides with the natural trend to cooling, the study of such transitional stages is important for understanding the underlying processes of the climate changes.”
Let’s parse that:
evident climatic and environmental instabilities
The transition…from the Last Interglacial…to the Early Last Glacial…is marked by at least two warming events
a strong increase of environmental oscillations during the very end of the Last Interglacial and the beginning of the Last Glaciation.
‘‘human-induced’’ global warming coincides with the natural trend to cooling”
The end of the most recent interglacial, the one best preserved, especially since Holocene sea level highstands were much lower, provides ample and dramatic evidence of numerous extremely abrupt climate changes noted around the world. The two strong thermal pulses, the second one right at the end being the strongest, netted a sea level highstand that was anywhere from +6.0M amsl to perhaps as much as +52M amsl. There are many lesser steps and backsteps of sea level well-preserved at many locations around the world.
I could go on, but the point is that you really cannot expect a sentient scientist to take such a report seriously. The Signal to Noise Ratio is blatantly mind-boggling!
If you are really serious about getting my attention as regards “extreme weather events” then you are going to have to throw boulders over 20 meter high cliffs, and reshape the Bahamas, do far better than the geologic deposits still visible from the recent Japanese Tsunami, and dramatically better than the IR5 2100 estimate of +0.8 meters amsl.
Perhaps few realize that in able to even detect anything anthropogenic climate related, we have to be able to separate each such event from the normal, natural end extreme interglacial climate “noise”.
I mean I have to be able to distinguish anthropogenic extreme climate events from the typical climatic “madhouse” that seems to always attend the ends of the post-MPT interglacials. If you are going to play the end extreme interglacial climate game, then you definitely need to up your game. Capiche?
Otherwise, this is nothing but a shallow silly buggers game.
“I see your Anthropogenic Extreme Climate Change events and I raise you the end-Eemian………………..”
Earth, number one. WARP 3.
“gravimetric field displacement manifold” GFDM, fascinating.
My error.
Yes, William; the alarmists have this precisely backwards. Any real increase in severity of weather or climate events will herald the end of the Holocene and incipient glaciation, the path to which will be rocky and icy.
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Which makes this REALLY interesting:
“The situation is completely different for a CO2 concentration of 240 p.p.m., which is close to that observed at the end of MIS19. In this case all four model versions simulate rapid ice growth several thousands of years before the present and large ice sheets exist already at the present time (Extended Data Fig. 1). This means that the Earth system would already be well on the way towards a new glacial state if the pre-industrial CO2 level had been merely 40 p.p.m. lower than it was during the late Holocene, which is consistent with previous results.”
Paywalled here: http://www.nature.com/nature/journal/v529/n7585/abs/nature16494.html
Could it possibly be? Is it even possible, model-wise, regulatory-wise, that we could return Gaia to her normal, natural climate-change norm of glacial inception by ourselves?
If such is even remotely possible, then, these days, watching all the going-on’s, I am not so sure that I object. Anymore. Climate change, extreme climate change would appear to be the “chlorine in the gene pool” where the genus Homo is concerned. See:
“An examination of the fossil record indicates that the key junctures in hominin evolution reported nowadays at 2.6, 1.8 and 1 Ma coincide with 400 kyr eccentricity maxima, which suggests that periods with enhanced speciation and extinction events coincided with periods of maximum climate variability on high moisture levels.”
http://www.manfredmudelsee.com/publ/pdf/Trends-rhythms-and-events-in-Plio-Pleistocene-African-climate.pdf
Could it really be that simple? And here we are at the Anthropocene extension of the Holocene, well-adapted to central heat and cooling, even contemplating ending both.
One is left to wonder if we could actually precipitate our own genetic “bottleneck?” The problem is, would that be a bad thing for the current iteration of the genus Homo?
Yikes! Over my pay grade; I’ll stick to geo-engineering and biosphere enhancing with CO2.
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You a actually read William’s million word post? Get outta here !
He’s thinking ahead of the box. I have trouble enough just getting outside of it.
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Thus Kim’s regular worry about the cold.
One more reason I think alarmist scientists are motivated by more than a desire to expand our knowledge. I don’t worry about the next glaciation because I understand the difference between geological time frames and human ones. But that doesn’t make the fact that our planet is due for its next regularly scheduled change in climate to away.
Younger Dryas rapidity mocks your differences between geological and human time frames, but your general point holds. And yes, glaciation appears almost like clockwork.
================
Reasons to worry about cold are eg 2200 BC event, migration periods, LIA and volcanism such as experienced not long ago at all with Laki and Tambora. With much of this cooling you also get aridity in places you truly don’t want it.
As for volcanism, Eyjafjallajökull in 2010 was pretty hectic for Europe. Imagine if something vastly more polluting occurred and got lucky with the right jet stream. After the gassing deaths comes the freak weather…and then the cold. With Grímsvötn also erupting long term and the mother of all El Ninos following in the post 1789 years, you can see why there was trouble in Europe and beyond after Laki started belching in 1783.
None of the major cooling events mentioned above are remote, any could be repeated in some degree right now. Hell, even the 1970s had the pensive classes of the day fretting over some very minor chilling.
I’m not worrying too much. I just reckon we should have a versatile wardrobe.
Kim,
I understand that when it comes, it could come quickly.
With CO2 at 400 ppm +, there is no possibility of cooling with this climate system unless there an astounding series of volcanic eruptions or a major change in the sun. The stadium wave? Forget about it. The AMO? You have to be kidding.
The single biggest problem with climate alarmists is that they simply do not believe in climate change.
The colossal forces which put Bass Strait under the ocean less than eleven thousand years ago are now deemed to be dissipated or irrelevant. Yet the merest tickle of new warming or sea level rise (what do they expect in the warm phase of an interglacial?) sets off their alarms. Even some skeps buy into the bother of arguing whether these inevitable and predictable effects have “paused”.
The Storegga Slides – a complex weather event which managed its destruction without any help from your SUV – made Britain an island. This series of events did not occur millions of years ago in any gradual fashion. They occurred a little over eight thousand years ago, during what was already the Middle Stone Age. In climate terms, that’s RECENT.
Climate change is the least favourite subject of those who constantly raise the subject of climate change.
Which is beyond odd.
Looks like Titely is trying to compete with Mann in a contest of who can attract the most government money to Penn. State. Lord knows the University needs their tithe to cover legal fees resulting from the Paterno/Sandusky fiasco.
Does Titely work for Mann. Mann has the big climate research institute.
They’re both at Penn. State. I assume Mann has seniority and Titely is trying to establish his credentials as a money making machine after retiring from the Navy, which is probably why they hired him.
“The basic physics of how the climate system works and the broad-scale impacts of rapid addition of greenhouse gases on the climate system are well understood.”
I regard natural variability as largely solar forced rather than internal and chaotic, and would suggest that changes in teleconnection regimes from the mid 1990’s were driven by declines in solar, but are being falsely attributed to GHG forcing. Such as the warm AMO driven drying of continental interior regions, which could easily give rise to the idea that increased GHG’s will increase drought.
“However, much is still to be learned about how specific weather events are effected by the changing climate.”
With solar components acting on atmospheric teleconnections at down to daily scales, there’s much to learn about how the climate is effected by weather events. Most of the regular positive and negative AO/NAO episodes are solar forced, and will reach similar high and low values regardless of a 1°C rise in the global mean surface temperature.
The first quote is false while the second is unclear (changing from when?). I think chaotic oscillation is the big driver, but all we have at this point is conjecture, there being almost no research.
I have a large volume of correlative evidence of the solar forcing of weekly to monthly scale temperature anomalies through CET. The bias of the positive and negative AO/NAO episodes over time then drive the oceanic oscillations of ENSO and the AMO. With negative AO/NAO associated with El Nino and a warm AMO.
Does a warmer world effect the range of AO/NAO values? Well the notable recent change is an increase in negative NAO since the mid 1990’s, which is the complete reverse of how increased CO2 is modeled to effect the NAO. And the depth of negative episodes has resulted in UK weekly/monthly temperatures equal to some of the coldest in the Maunder Minimum, in both ends of 2010, and in March 2013. I don’t see any evidence for a higher mean global surface temperature increasing positive AO/NAO values either.
Maybe a case of putting the cart before the horse, and becoming completely confused as a result.
From the paper –
“The natural daily and seasonal variability of the weather can mask the changes in the overall climate. However, when people experience extreme events that they believe may be occurring with different—usually greater—frequency in time or with increased intensity, many ask about the connection between climate change and extreme events.”
This seems to overlook the fact that climate is merely the average of weather events which have already occurred. Climate lags weather, obviously, being dependent upon it.
Obviously, to me at least, any weather event is within the boundaries of natural variability. Mankind is part of nature. Man’s activities no doubt cause variations in the weather, and hence the climate, if the physics of the atmosphere are governed by chaos. The movements of the continents, the movements within the mantle and core, as a result of the redistribution of the Earth’s matter, no doubt also have unpredictable effects of unknown magnitudes.
When Lorenz delivered his talk “Predictability: Does the Flap of a Butterfly’s Wings in Brazil Set a Tornado in Texas?”, he stated he was asking a literal question, as yet unanswerable either way. Climatologists, and their supporters, seem to dismiss chaos as governing the operation of the atmosphere, even though the IPCC somewhat grudgingly admits the fact, and then goes on to ignore it in practice.
If climate is defined as the average of weather over a 30 year period, then the “attribution of extreme weather events in the context of climate change” can be rewritten as “attribution of extreme weather events in the context of the change in the average of weather over a thirty year period which includes the extreme weather events which have occurred.”
As a Warmist would say, “Duh!”
In any case, yet another pointless publication, achieving nothing at all. Maybe the scientists involved just wanted a nice paid holiday in Washington. There are worse ways of wasting time!
Cheers.
Mike says
“Obviously, to me at least, any weather event is within the boundaries of natural variability.”
_____
Well that’s no surprise. It’s obvious, to me at least, that you operate with a closed mind, probably because if you didn’t, all the hot air would escape.
max10k,
I assume you are trying to be insulting. If so, you need to lift your game.You are not having much impact.
If you need any help in developing gratuitously offensive comments ad hominem, please let me know. I’ll do my best to help.
Possibly the mental disorder which you claim to possess precludes your ability to develop a cogent and coherent train of thought. Or maybe you merelyclaim a disorder in an attempt to engender sympathy?
Let me know whether you are being honest or otherwise, and I will consider adjusting my care level from its current level of zero.
Cheers.
Mike Flynn | March 15, 2016 at 1:08 am |
“Possibly the mental disorder which you claim to possess precludes your ability to develop a cogent and coherent train of thought.”
________
I’m good at developing cogent and coherent short trains of thought.
max10k,
You wrote –
“I’m good at developing cogent and coherent short trains of thought.”
Is this an example of something that you assert is a fact because you believe it to be so?
I suppose it explains why Warmists can believe in the impossible. Why let inconvenient facts interfere with a firmly held belief? Pretty soon you can believe that CO2 is evil, that you can warm stuff using the magical powers of CO2, or even believe that Michael Mann received a Nobel Prize!
The possibilities are endless! Have you tried believing in World Peace or a cure for cancer? That might be worthwhile.
Cheers.
There was a time when the most successful engineers were the ones most adept at motivating the stokers.
===================
And by “short” max means as long as a gnat’s pecker.
Excellent Summary!
Mike Hulme has done the best analysis on the state of X-weather attribution.
https://rclutz.wordpress.com/2016/03/14/x-weathermen-are-back/
Yes, lucid, and timely. Light at the end of the tunnel. The quality of the source is diffuse, not like a headlight.
=================
Oh, yes, note the end of the tunnel in view. Also, note the locomotive, or not.
==================
thanks much for this link to Hulme’s paper
I too am critical of NAS efforts to attribute extreme weather events to human-caused climate change when the NAS has studiously avoided addressing precise data and observations that show the Sun’s core is the pulsar remnant of the supernova that made our elements, birthed the solar system five billion years (5 Ga) ago, and still sustains every atom, life and planet in the solar system today.
http://crescopublications.org/pdf/ASSOA/ASSOA-2-005.pdf
spam
Scientists are developing the ability to do this, says the report, by analyzing two worlds: the real one, in which atmospheric carbon dioxide levels are rising as a result of human activity, and an imaginary one in which the Industrial Revolution never happened and the climate is only influenced by solar and volcanic activity. By running computer simulations for both worlds, they are able to gain a sense of how much more likely a particular drought or flooding event is to occur in one world or the other….
They finally listened to kim!
When JCH bets something of value on the winner of next year’s Super Bowl based on the outcome of running a season of Madden NFL 2016, maybe I will pay attention.
I have flown in hollow tubes that have wings and driven across bridges suspended on cables and walked on glass perched far enough above the ground to assure death… all modeled.
The Tacoma Narrows Bridge was modeled.
http://www.wsdot.wa.gov/TNBhistory/Machine/photos/M3-1-6264.jpg
JCH,
So let me get this straight. Just because some mathematical models work, that means all mathematical models work?
Lordy, Lordy!
Who can argue with logic like that?
LMAO. You people are both abjectly hopeless and pointless by silliness. There are 10s of thousands of bridges, either modeled by hand or by computer, that have stood the test of time. When bridges fail, it is most often because of damage by collision, flooding, earthquakes, extreme cold, extreme heat, lack of inspection and maintenance, etc.
ACO2 is the control knob. It’s getting hotter. Every week there is new science. None of it says otherwise. And… I think genuine skeptics need to start asking some hard questions about recent observation-based estimates that found CS was low.
JCH,
Except where higher levels of CO2 lead to more ice in Antarctica?
Then this: “And even in times when there were ice sheets when CO2 was higher than today, those ice sheets were variable; they grew and shrank.”
They grew and shrank………
https://www.washingtonpost.com/news/energy-environment/wp/2016/03/11/the-more-we-learn-about-antarcticas-past-the-scarier-the-present-looks/
The attribution conversation as discussed in this NAS work considers more than just your ‘control knob’ and rightly so. And even the inclusion of CO2 is worth the review. As well as none anthropogenic attribution such as ocean cycles, El Nino/La Nina, etc.
As if we understand how ‘global’ climate works.
If you think any of that is presents a problem, you’re wrong. You just want it to.
Climate scientists have always studied natural variability.
So JCH, are you claiming GCM’s are as well validated and bounded as structural models used in engineering?
JCH, the word you keep forgetting is “validated”, validaded models.
And even validated ones mess up once in a while, go figure. Then a bridge collapses.
It’s 200 pp. I probably won’t make any comments on it. (cheers! applause!)
An honest response.
A bit surprised by some of the reaction in the comments. Attribution does not mean (from what I’ve read of this so far) to anthropogenic causes only.
From the work: “There are compelling scientific reasons to study extreme weather event attribution as well. The basic physics of how the climate system works and the broad-scale impacts of rapid addition of greenhouse gases on the climate system are well understood. However, much is still to be learned about how specific weather events are affected by the changing climate. Improved attribution, and ultimately prediction of extreme events, will demonstrate an even more nuanced and sophisticated understanding of the climate system and enhance scientists’ ability to accurately predict and project future weather and climatic states.”
and
“In addition to exploring framing and attribution methods, the report provides a synopsis of attribution of nine specific types of extreme events. Not every type of event discussed is a pure meteorological event. Droughts, floods, and wildfires all have human, as well as natural, components. Land management, controlled burning, and dams and levees impact the magnitude and frequency of these extreme events. However the committee believes there is a large weather and climate signal to these types of events, and climate scientists are frequently asked to comment on them. ”
Leaving out CO2 (admittedly a large omission) the understanding of natural processes and man’s alternative impacts (modification of environment) seems a worthy goal.
Page 100’s chart indicates a level of confidence about the state of the science depending on event type. Weather and forecasting improvements should arise over time.
Heck, most agree the climate is changing and has done so over time. An improved understanding lacking the wicked finger of fate being pointed at CO2 soley, seems a focus worth doing. I commend the considerations being broadened. I have more to read, but this is a viewpoint from what I’ve seen so far.
Side note, but of interest: (dates to 2014) http://www.wunderground.com/blog/weatherhistorian/heavy-rainfall-trends
It is very likely the “cause” of climate change is weather. We are currently experiencing an extreme event that has been called a hiatus in global warming, an unanticipated pause in the inexorable rise in average global temperatures that government scientists predicted, leading to colder winters than had been anticipated.
The foregoing has been, the representation of a counterfactual world that reliably characterizes the probability, magnitude, and circumstances of events in the absence of human influence on climate.
We know neither enough of natural causes or of man-made causes for these representation of the supposed factual and the proposed counterfactual to be anything other than exercises in the imagination. Hey, nothing wrong with that until someone wants policy to flow from it without a little further grounding.
============================
A problem in spending time and resources on an analyses of specific extreme events over the last few thousand years is that most will have occurred in regions adding up to the 3/5ths of the world that are covered water.
I have been watching the Lake Shasta (California) water level rise since multiple storms over the last several months have rained and snowed across Northern California.
Lake Shasta, California’s largest reservoir, is endangered of filling up to its peak of 1067 feet above sea level having just passed its historical average this last Sunday, rising 50 feet just in the month of March so far. Imagine that; filling a reservoir from a 4 year drought low water level to nearly completely tippy topsy full in three months. Now I say that is Un-Precedented!
This is extreme reservoir replenishment. I think the climate causal climatologists are right, this is extreme weather, extreme climate change: a sudden and un-expected improvement for the whole State of California.
Where are the catastrophocists? Oh My God. What can we do? California will now have sufficient water to survive another 4 year drought. I can’t believe it! This is truly catastrophic. What will happen to the dooms day narrative? What will the Los Angeles Times editorial crew say about man made climate catastrophe? What will Micheal Mann say now that he has been proven wrong again, he saying that the California soil will be so dried out that NOTHING will grow; desert; starvation; migration; displacement. This is now all changed because of catastrophic weather improving water retention and supplies.
What will I say to my California grandchildren? Of course, I am at fault.
Where were you when the skeptics bombarded this blog with predictions of looming La Nina dominance?
Same with Folsom Lake. The local alarmists always act incredulous when I tell them 1976/77 was worse.
The operative logic is as follows:
So, humanity obviously must immediately stop putting more CO2 into the atmosphere.
Do they try to estimate non-occurring extreme events – stuff that should have been expected to happen but didn’t? Otherwise they have a hidden one way bias.
Its like a soccer team not scoring. Suddenly every goal is important because that’s all there is to analyse. But a good coach would understand that the reason behind not scoring might be more incisive.
The question has long been between increased energy in the system causing increased severity vs decreased polar/equatorial temperature gradient causing decreased severity. I’m amused that they are countervailing tendencies, but note that the p/e gradient change will have a larger percentage value change than the increased energy one. It’s likely it will prevail.
Also, the first is intuitively obvious even to those ignorant of much atmospheric physics, the second only obvious to the likes of Richard Lindzen.
================
Kim, if “more energy in the system” causes more powerful storms then the effect should be immediately obvious. There should be a direct correlation between “Hottest Ever” and “Worst Storms Ever”.
The year 2015 must have seen a bumper crop of terrible storms, and February 2016 must have been absolutely horrendous. Poor Munich-Re!
And I’m sorry, samD, that is slightly off your very cogent observation. It’s always the bias, the unseen bias.
============
samD, well put. And why does nobody ever look for the cause of NICE weather?
Of course not. You are silly! We are waiting for the End of human race, and you want to count nice days. /sarc
When you conduct poor climate science you try to avoid the first fatal flaw by duck shoving it; the next fatal flaw, ditto. By the nth fatal flaw it has become so easy that you get bold and ambitious. You propose grand expenditures based on wishful consequences of your story.
Legend has it that the pirate could take several steps along the plank before the downfall.
Downfall awaits these authors, who are presumably unable to deal with three flaws from the start.
1. Nobody can answer the question ” What is the quantitative link between the concentration of CO2 in the atmosphere, and its temperature?”
2. Or the second question, “What quantitative method allows the clear attribution of a climate change to natural or not?”
3. The third question, “What sampling time period is needed to overcome uncertainties from being on a limb of some long term cyclic processes?”
Buildings crumble when foundations fail.
Geoff.
You can’t trust adult peer review. Let’s let the kids do it.
Extreme weather events prove even less about natural variability vs man caused variability than the bogus models do. It’s like they’ve just given up on that.
The authors may or may not be correct for the Pacific and the Indian Ocean, but it looks as they could be wrong as far as the N. Atlantic is concerned.
http://www.vukcevic.talktalk.net/ACE2.gif
“Like the surgeon general’s 1964 report connecting smoking to lung cancer, the report from the National Academies…..” (NYT op-ed)
This is just soo Naomi Oreskes. How about this variation, ‘like the American Heart Association 1961 pronouncement on the link between saturated fats and cardiovascular disease,….’ Smoking and lung cancer etc was a clear link, initially argued over because of the quality of data and statistical methods, which became ever clearer over time. Saturated fat, by contrast, seems more CO2 like. Definitely implicated in CVD it seems (whatever the hype to the contrary), but at quite marginal levels of risk. Relative risk in the 1.15 – 1.30 range for broad risk, versus RR in the 10 – 20 for smoking. It seems saturated fat is just one of several risk factors in this general risk range. And the remedy (alternative fats) probably worse than the ‘disease’!
“But some of our weather has changed significantly, and now a new report from the National Academies of Sciences, Engineering and Medicine has outlined a rigorous, defensible, science-based system of extreme weather attribution to determine which events are tied to climate change.”
The weather has changed. The climate has changed.
To what?
Andrew
> To what?
And from what ? And when ? Over what time period ?
Such tiresome, vain little Noble Cause Corruptors they are …
They seem to have skipped an essential step. Before one can attribute extreme events to human influence, one must first attribute most or all of the warming to human influence. This has simply not been done scientifically. If the warming is natural than so are its effects, if any.
Note how they duck the issue here, saying “Confidence in attribution findings of anthropogenic influence is greatest for those extreme events that are related to an aspect of temperature, such as the observed long-term warming of the regional or global climate, where there is little doubt that human activities have caused an observed change.”
But how big is this supposed observed change? If it is a tiny fraction of the warming then it is a tiny fraction of the influence of that warming on extreme events, if that. Do they address this central prior issue? If they just assume that most or all of the warming is human-induced then this is simply a warmest tract, not science.
kim has poetikized us many times that without mankind’s earth saving efforts, the global mean surface temperature would be much lower right now; as in, mukho kolder. And now their models agree: without man, this place would be an ikeberg. I figure man is responsible for 125 – 150% of the warming. It’s just good skience.
Today you all like your science down to earth and hardly muddy at all. What a picture.
You are finally getting your head around the melody, JCH. The higher the sensitivity the colder we would now be without man’s efforts. You had better hope that the recovery from the Little Ice Age was predominantly natural, for if man has done the heavy lifting of warming, we’re running out of fuel.
==================
There is no finally. My positions are unchanged. Observations that are in disagreement with ACO2 are most likely wrong: HadCrappy3, satellites series. CS is much higher than the recent observations-based papers are claiming. The PDO is a beast, though it can no longer cause actual cooling. It can slow down warming for a brief time. When the PDO and ENSO are perfectly aligned on the hot side, this rock is going to warm like crazy. The AMO is a feckless joke of an ocean cycle. It does nothing.
Hope is nonsense. Physics is all we have. The enemies of physics are a joke.
You attribute the warming from the coldest depths of an end stage Holocene to AnthroCO2. If you are right we cannot release enough CO2 to stop the incipient glaciation.
===================
We can try, though. Shall we dance?
==============
“Hope is nonsense. Physics is all we have. The enemies of physics are a joke.”
Somebod got dey Preachin’ hat on todaye.
Quite the spectacle.
Andrew
If only we had some decent physics. The physics of things like the sun, the oceans, clouds, LIA-MWP cycles, chaotic feedbacks, etc. Instead we have tens of billions of dollars worth of CO2 control knob stuff, with a little TSI and a few volcanoes thrown in. Basically cartoon science.
Well said David. Warmists are such simpletons!
Earth’s climate sensitivity has long been subject to heated debate and has spurred renewed interest after the latest IPCC assessment report suggested a downward adjustment of its most likely range1. Recent observational studies have produced estimates of transient climate sensitivity, that is, the global mean surface temperature increase at the time of CO2 doubling, as low as 1.3 K (refs 2,3), well below the best estimate produced by global climate models (1.8 K). Here, we present an observation-based study of the time period 1964 to 2010, which does not rely on climate models. The method incorporates observations of greenhouse gas concentrations, temperature and radiation from approximately 1,300 surface sites into an energy balance framework. Statistical methods commonly applied to economic time series are then used to decompose observed temperature trends into components attributable to changes in greenhouse gas concentrations and surface radiation. We find that surface radiation trends, which have been largely explained by changes in atmospheric aerosol loading, caused a cooling that masked approximately one-third of the continental warming due to increasing greenhouse gas concentrations over the past half-century. In consequence, the method yields a higher transient climate sensitivity (2.0 ± 0.8 K) than other observational studies.
Yes. About what I’ve been telling you for years:
http://climatewatcher.webs.com/TCR.png
And in the context of the mythical ECS:
http://climatewatcher.webs.com/TCR_AR5.png
Lol. You do not tell me nuthun’.
“This has simply not been done scientifically.”
The IPCC is all its majesty has simply decreed that it is so (that warming is mostly anthro.) Magical powers are so much more convenient than tedious old science.
(aka pokerguy)
More defactualized propaganda from the establishment’s billionaire golden boy:
Up to 13 Million Americans Are at Risk of Being Washed Away
http://www.bloomberg.com/news/articles/2016-03-14/up-to-13-million-americans-are-at-risk-of-being-washed-away
The study uses one highly speculative assumption as a launching pad to blast into yet another orbit of speculation.
It’s speculation all the way down.
What amazes me is that the American public gets bombarded almost daily with this sort of propaganda, but the majority has tuned it out. I guess screaming “The sky is falling!” only works so many times, before people tune the warnings out.
http://i.imgur.com/I2Ezx7W.png
http://i.imgur.com/GkWmLfo.png
I don’t see how they’ll distinguish manmade global warming from the gods being angry, which is the same thing.
Here’s the tell:
When there is a single day or month or year of normal weather, people don’t say – well carbon dioxide must have cause all this fair and normal weather.
Hypothesis chasers are only interested in something bad to confirm an emotional need.
Unfortunately, normal weather is a deep misnomer. It really means average weather and the paradox is that average weather is a rare event. Chaos is like that.
Most weather phenomena are determined by motion of the atmosphere.
Motion of the atmosphere is not determined by mean temperature.
Motion is determined indirectly by thermal gradients.
Maximum atmospheric kinetic energy occurs aloft ( ~ 300 millibars ).
This represents the jet stream.
GCMs predict an increase in the relevant gradient ( Hot Spot ).
Observations indicate little change in the relevant gradient.
http://climatewatcher.webs.com/HotSpotGradient.png
I suppose it goes without sayin’
only bad weather events are anthropogenic
and extreme
“extreme” is way more cool than “natural”
Gaia will bless us with nothing but fair weather if we allow her.
question …
does 100 below in Antarctica count as extreme?
Deconstruction:
As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Assertion??? Many intense weather events ( strong tornadoes, hurricanes, global drought determined by satellite ) have decreased or exhibit no significant trend.
Climate models simulate such changes in extreme events, and some of the reasons for the changes are well understood. Models above don’t seem to be verifying, so this would appear to be projection, not validation.
Warming increases the likelihood of extremely hot days and nights, With respect to what? Hot compared to past averages? Perhaps. But increases in absolute humidity could mean LESS variance from current averages, since increased latent heat increases the energy exchanged with the same amount of motion. That’s what Manabe 1980 found.
favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall Yes, though all precipitation events depend upon transport of water vapor, many times from far remote tropical regions which always have the potential to flood. The recent Louisiana flooding is a good example. It occurred as the result of a strong mid-latitude cyclone that stalled in the region allowing ‘training’ of moisture and precipitation bands over the same area. Such events will always cause flooding because of the dynamics, and are not constrained small variation in temperature ( this event occurred in March, after all, March? Winter? Colder?
and leads to evaporation that can exacerbate droughts. This is nonsense since every drought of note is determined not by evaporation rates, but by the lack of precipitation. The lack of precipitation, in turn, is the result of a lack of mid-latitude cyclones. Further, evaporation is determined by temperature, wind, sunshine, available water, and the dryness of the air. Evidently, factors other than temperature are more important to evaporation that temperature is!
http://images.slideplayer.com/16/5061635/slides/slide_15.jpg
Are you saying warmer temperatures can’t exacerbate droughts?
Droughts begin with fewer numbers of precipitation events.
Droughts end with greater numbers of precipitation events.
Global average temperature doesn’t have a demonstrable cause to change precipitation events.
TE,
“Global average temperature doesn’t have a demonstrable cause to change precipitation events”
What about the warmer air holds a higher level of moisture leading to a greater level of precipitation during the precipitation events? Maybe not GAT, but regional? Has GA precipitation increased/decreased/stayed same?
“Drought is a deficiency in precipitation over an extended period, usually a season or more, resulting in a water shortage causing adverse impacts on vegetation, animals, and/or people. It is a normal, recurrent feature of climate that occurs in virtually all climate zones, from very wet to very dry.”
When is a ‘deficiency’ declared? What’s a season?
“Are you saying warmer temperatures can’t exacerbate droughts?”
TE won’t answer that.
.“Are you saying warmer temperatures can’t exacerbate droughts?”
TE won’t answer that.
Droughts cause higher ( and lower – see winter & summer for DustBowl American plains in 1936 ) temperatures because the lack of precipitation means the soil has a lower heat capacity.
People get confused by cause and effect and assume higher temperatures cause droughts – they do not.
Further, evaporation rates decrease as a drought goes on.
Why? Because there’s less water to evaporate. Some try to run the jive – well, precipitation starts a drought, but evaporation continues it. Well, no. evaporation declines as a drought goes on.
Now, as I wrote above, of course, temperature is a factor in evaporation.
Eating pepper is also a factor in gastric cancer, but you’re not going to stop – why?
Because in the same way that pepper is not a significant risk, temperature change from global warming is not a significant factor.
Storm tracks not temperature determine droughts.
I’ll try again with this slide ( from Piexoto and Oort ):
http://player.slideplayer.com/16/5061635/data/images/img15.jpg
Temperature is a factor in evaporation, but look at the chart.
Evaporation is greater in the winter hemisphere ( when/where temperatures are lower ) than in the summer hemisphere.
That’s because:
cold air is drier ( and thus more evaporation )
and the winter hemisphere is windier ( and thus more evaporation ).
Those factors are, by observation, greater than temperature and sunshine which are greater in the summer hemisphere.
It is not clear that global warming should produce more cold dry air or greater wind speeds which appear to be the dominant factors from this example.
What about the warmer air holds a higher level of moisture leading to a greater level of precipitation during the precipitation events?
Yes, in general, to the extent that it occurs, an increase in humidity increases precipitation potential. But not demonstrably the precipitation events ( usually the ‘mid-latitude cyclone’ ).
Also, I was in Texas during August of 2011 ( severe drought ).
It was hot.
But, it was also typically humid.
Without dynamics, the potential precipitation of the humid air was never realized.
“Drought is a deficiency in precipitation over an extended period, usually a season or more, resulting in a water shortage causing adverse impacts on vegetation, animals, and/or people. It is a normal, recurrent feature of climate that occurs in virtually all climate zones, from very wet to very dry.”
Very apt.
TE,
Do you think (or foresee) that “Yes, in general, to the extent that it occurs, an increase in humidity increases precipitation potential. But not demonstrably the precipitation events ( usually the ‘mid-latitude cyclone’ ).” can be attributed after the fact?
Abstract: The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic climate change. A clear concurrent change in precipitation, however, has not been confirmed. Vapor pressure deficit (VPD), combining temperature and humidity, is utilized here as an indicator of the background atmospheric conditions associated with meteorological drought. Furthermore, atmospheric conditions associated with warm season drought events are assessed by partitioning associated VPD anomalies into the temperature and humidity components. This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts. By classification of a decade of extreme drought events and tracking them back in time, it was found that near surface atmospheric temperature and humidity add essential information to the commonly used precipitation-based drought indicators and can advance efforts to determine the timing of drought onset and its severity.
This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts.
Nonsense.
There was drought in Texas because it didn’t rain much.
It didn’t rain much because ( and this is verifiable ) there were fewer mid latitude cyclones passing over Texas.
These events occur from waves in the jetstream half a world or more away.
Trying to invoke warming is superstition akin to virgin sacrifices.
We know how precipitation forms and its time to step out of the dark ages.
It would be nice to see some references to papers that conclude that climate change won’t have any impact on droughts.
Joseph,
If one has sufficient evidence to support the argument that global warming has been occurring since say about 1950, then would a paper which states that drought occurrence globally has not increased while that warming took place, suffice? http://www.nature.com/nature/journal/v491/n7424/full/nature11575.html?WT.ec_id=NATURE-20121115
I read many projections (of course utilizing modelling) that this will not be the case going forward, but looking back in time it appears to be so.
JCH:
Any citation available for your quoted Abstract?
Back in the early 1990s, Balling and Idso empirically showed that drought conditions declined slightly for the 35 years after 1954 (chosen as the beginning of the trend of rapid GHG increase due to post-WWII industrialization). Muschinski and Katz found no significant drought trends for that period in their model-free 2014 paper. http://arxiv.org/pdf/1401.7368v1.pdf
Someone needs to explain what caused the influence of GHGs to change in more recent decades to buttress your Abstract’s claim that “The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades…”
Or perhaps it was just the change from empirical data to model outputs?
Oplusa
JCH,
I’d say your link pretty much supports that “Are you saying warmer temperatures can’t exacerbate droughts?” haven’t been proven to do so based on the abstract statement: “A clear concurrent change in precipitation, however, has not been confirmed.”
This segment: “This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts.” one would expect during a drought, any drought, correct? Warmth, evaporation, reduced soil moisture leading to reduced evaporation and lower humidity.
In looking for that answer found: “Droughts commonly are referred to as “dry” in the sense that not only does less precipitation fall, but also the air is drier than usual. Several single- station case studies support this concept.
Relative humidity is a commonly used measure of atmospheric water vapor. Relative humidity depends on two factors-the absolute quantity of water vapor in the air (absolute humidity) and the air temperature. Baldwin (1957) presents a case study of 2 dry years and 2 wet years at San Antonio, Tex. (table 2). The mean relative humidity for the dry years was 56 percent, compared to 64 percent for the wet years. Potter (1958) compiled normal relative- humidity data for May collected at five stations in central Canada and compared these data with the data for the dry May of 1958. The five-station average relative humidity for May 1958 was about 50 percent compared to average normal relative humidity for May of about 65 percent.”
Your friend Karl: http://geochange.er.usgs.gov/sw/changes/natural/drought/
This too, may provide some perspective (1200 years or so): http://www.pnas.org/content/107/50/21283.short
I was responding to this – typically humid – as it was pleasantly dry that year. If weren’t for all the trees dying, it would be one of my favorite years in Texas.
Also, I was in Texas during August of 2011 ( severe drought ).
It was hot.
But, it was also typically humid.
JCH,
And yet neither are apparently ‘exacerbated’ nor even attributable to GW/CC based on a preponderance.
TE STILL wont answer
‘“Are you saying warmer temperatures can’t exacerbate droughts?”
TE won’t answer that. STILL.
TE. let me show you what an answer looks like.
“Are you saying warmer temperatures can’t exacerbate droughts?”
1. Yes. That is what I am saying
2. No, that is not what I am saying.
After you answer the simple yes or no question, we can proceed.
Steven Mosher,
You wrote –
“After you answer the simple yes or no question, we can proceed.”
Maybe if he doesn’t want to play your game with you, you could always sit in a corner and play with yourself!
So I’ll ask you a simple question – are you still pretending to be a scientist?
After you answer the simple yes or no question, we can proceed.
Only if you really want to, of course!
Cheers.
Run out to West Texas and check the plants in 1938, 1998, and 2011. Or, see if 60 million trees die of thirst in Harris County every year, or was 2011 sort of unusual. Maybe the Lost Pines Forest by Bastrop burned to the ground every year and nobody noticed that was happening until 2011 when the evil media made a big deal out of it.
http://berkeleyearth.lbl.gov/auto/Regional/TAVG/Figures/texas-TAVG-Trend.pdf
But can parched earth get even drier because of heat? Might as well be zero will still be might as well be zero. In the past there were deserts, so hey, everything is going to be great.
JCH,
I’m not sure what to think about Cherrapunji in India. It’s a lot rainier than places with lower temperatures. Does this mean that cooler places would get more rain if they got hotter, or would really dry places get more rain if their temperatures fell?
All a bit tricky. Maybe temperature (by itself) doesn’t have much to do with rainfall – or drought. What do you think?
Cheers.
If I say little green men came to visit last night – prove that they didn’t, you would be indignant and ask me for evidence.
If you say temperatures exacerbate droughts, I’ll ask you for evidence.
Look at all historical droughts. Find one, just one, in which precipitation was ‘normal’ but somehow evaporation caused a drought. I’m confident you won’t find any. Why? Because evaporation does not cause drought – lack of precipitation does.
TE, there is a difference between causing and exacerbating. Do you not understand that?
I was responding to this – typically humid – as it was pleasantly dry that year.
The average dewpoint at DFW for Aug 2011 was 64F. You are confusing liquid water and water vapor.
So climate change can exacerbate droughts?
TE, there is a difference between causing and exacerbating. Do you not understand that?
No.
Q: When is evaporation greatest: Before, At the beginning, In the middle, or at the end of a drought?
A: Evaporation is greatest before a drought because there is water to evaporate and quickly heads toward zero as a drought progresses.
So climate change can exacerbate droughts?
Droughts from time immemorial have been a representation of natural climate change as understood by variability in circulation.
There is no reason to believe greenhouse gas forcing will be a significant change to that.
Ok cite a paper that claims as you do that climate change won’t affect droughts. I asked before and got cricketes.
Ok cite a paper that claims as you do that climate change won’t affect droughts.
Did anyone prove the Aztec gods didn’t exist before they made human sacrifices?
No, but that doesn’t mean they were right.
Well TE I think I will stick with the experts who study the impact of climate change on drought and know what they are talking about.
Well TE I think I will stick with the experts who study the impact of climate change on drought and know what they are talking about.
If you find any that don’t agree that droughts are caused by lack of precipitation and ended by more frequent precipitation, let me know.
I will let you know if any think that climate change won’t impact droughts.
I will let you know if any think that climate change won’t impact droughts.
So we should distinguish.
We could measure drought by frequency.
We could measure drought by duration.
We could measure drought by area.
You kinda agreed that lack of precipitation is responsible for drought.
So that means we wouldn’t expect change in frequency, duration, or area of drought, because in the general mean, AGW is theorized to increase precipitation, not decrease it and there’s no coherent testable theory of significant circulation change associated with AGW.
Temperature is a factor in evaporation, but since evaporation decreases as a drought evolves, evaporation is less and less a factor.
And the effect of global warming on evaporation is small.
Here is what Manabe found for a quadrupling of CO2:
http://climatewatcher.webs.com/ManabePrecipEvap.png
That’s a quadrupling, not a doubling.
And most of that difference is over the ocean not land.
This result is from a parameterization which may or may not be accurate and precise.
Then reflect that on the seasonal variation, there is more evaporation in the cold winter hemisphere than the warm summer hemisphere and you can put the role of AGW and evaporation in to proper context.
How old is that graph, TE? I found this paper by Manabe from 2002. And if everything you said is true then you should have no problem finding a paper that draws the same conclusion. So get back to me when you find it.
http://onlinelibrary.wiley.com/doi/10.1029/2001JD001195/full
I will let you know if any [papers] think that climate change won’t impact droughts.
And while you are at it, please let me know when any think that climate change won’t impact earth quakes, tooth paste sales, smartphone screen sizes or numbers of men who stopped beating their wives.
Why would global warming have any impact on any of that?
Yes, it appears quite similar to the 1980 results:
http://onlinelibrary.wiley.com/store/10.1029/2001JD001195/asset/image_n/jgrd9291-fig-0006.png
Precipitation occurs as the result of discrete events.
Climate models have no ability to predict these events.
Are you going to get back to me on this, TE?
TE
“Climate models have no ability to predict these events.”
Of course they do.
They predict these events.
Go get the output and look.
The real question is this.
1. Do they get the frequency MORE correct than a naive forecast
( the future will be like the past)
2. Do they get the amplitude MORE correct than a naive forecast
(the future will be like the past)
3. Do they get the spatial distribution MORE correct than a naive forecast?
no ability? hardly. Some ability? limited ability? how much ability?
and do we have a BETTER method than the farmer almanac?
Typically black and white statements like yours are found in reliious dogmas like CAGW and Sky Dragon Skepticism.
TE: “Climate models have no ability to predict these events.”
Of course they do. They predict these events.
Yes, they predict them, but implicit in my statement is:
Climate models have no ability to predict these events accurately.
No one can tell you where or whether drought will occur next year because no one knows how the storm tracks will vary next year. And they also don’t know how it will vary statistically next decade or century.
You can believe model output if you want, but it’s not verified.
“They predict these events.”
They also don’t predict them.
Andrew
TE
“Climate models have no ability to predict these events.”
Of course they do.
They predict these events.
Go get the output and look.
The real question is this.
1. Do they get the frequency MORE correct than a naive forecast
( the future will be like the past)
2. Do they get the amplitude MORE correct than a naive forecast
(the future will be like the past)
3. Do they get the spatial distribution MORE correct than a naive forecast?
no ability? hardly. Some ability? limited ability? how much ability?
and do we have a BETTER method than the farmer almanac?
Climate models have NO ability to accurately predict the events which cause precipitation! And you should know that.
The so called “Anomaly Correlation” ( not auto-correlation ) is a measure of that, though other more rigorous tests exist. An AC of .6 is determined to be “useful”. Ten day forecasts are not “useful”:
http://stream.ecmwf.int/data/atls01/data/data01/scratch/ps2png-atls01-95e2cf679cd58ee9b4db4dd119a05a8d-1dp3a3.png
And this is just the 500mb height field longwave – shortwave events, the ones that actually cause precipitation, are likely worse.
Turbulent Eddie March 16, 2016 at 3:40 pm
TE: “Climate models have no ability to predict these events.”
Of course they do. They predict these events.
Yes, they predict them, but implicit in my statement is:
Climate models have no ability to predict these events accurately.
____
TE, you may be missing Mosher’s point. A model’s forecast can be useful if it is more accurate than a naive forecast or no forecast at all. How much more useful depends on how much more accurate. Obviously 100% accurate is not necessary for a forecast to be useful.
Steven Mosher (and Joseph),
Joseph wrote –
“Are you saying warmer temperatures can’t exacerbate droughts?”
You are obviously confused, and attempting to project your confusion onto others. The Warmist tactics of putting words in the mouths of others is losing its impact. Temperature may or may not make a drought worse or better – who knows? In the finest Warmist tradition, you haven’t defined drought, and of course you will avoid a definition at all costs, because you still have not found Steven Mosher’s lost clue. Still clueless, it would appear.
Drought is not easy to define, according to the US National Drought Mitigation Centre. Here’s a short quote from it –
“Drought is an insidious hazard of nature. It is often referred to as a “creeping phenomenon” and its impacts vary from region to region. Drought can therefore be difficult for people to understand. It is equally difficult to define, because what may be considered a drought in, say, Bali (six days without rain) would certainly not be considered a drought in Libya (annual rainfall less than 180 mm).”
So what’s your definition? What’s climate got to do with it? Climate is only the average of weather, and neither of you can even tell me what the climate of California is, in any rigorous fashion. Is there a drought in California? Is it becoming worse or better? If much needed rain is refilling reservoirs, is your alleged global warming making the drought worse or better?
Warmists live in a state of continuous denial, as far as thinking that CO2 has any warming ability at all. Climatologists claim scientific stature for the trivial exercise of averaging past weather – mostly a relative handful of land based maximum and minimum thermometer readings.
A Warmist climatologist combines the worst of both worlds, being both blindly fanatical, and also convinced that the normal scientific process is irrelevant, as blind faith supplants consideration of facts.
But back to drought. As far as I know, Tibet has had at least four severe multi year droughts since 1705 CE. What impact did warmer or cooler temperatures have on theses droughts? Were they caused by warming, cooling, altitude, plate movement, or just lack of precipitation?
It seems that you really have nothing useful to contribute, but just keep parroting the Warmist mantra that CO2 must be evil because a climatologist said so! Climate is the average of past weather events. CO2 is essential plant food.
Cheers.
Reasons to believe that global warming is insignificant to drought:
1. In the global mean, part of the hypothesized AGW response ( subject to measurement uncertainty ) is water vapor feedback, meaning an increase in precipitation potential, not a decrease.
2. Drought is caused by a lack of precipitation. Precipitation is caused by atmospheric motion. Atmospheric motion is determined by the general circulation. The general circulation of the atmosphere is invoked by baroclinicity. Baroclinicity occurs because of the pole-to-equator thermal gradient. The pole-to-equator thermal gradient occurs because of the pole-to-equator gradient in net radiance at the top of the atmosphere of a spheroidal earth. But the effect of greenhouse gasses on the gradient of net radiance is small as I demonstrate in this post. And the general circulation has numerous variable states even with presumed ‘normal’ gradients as is exhibited by the history of ENSO circulations.
3. There has been global warming for decades, but satellite based estimates of vegetative indices do not indicate an increase in drought.
If anything, there appears to be a slight decrease in drought area:
http://www.nature.com/public/article-assets/npg/sdata/2014/sdata20141/images/sdata20141-f5.jpg
Increasing GHGs are responsible for a gradual increase in global radiative forcing. For the few extra W/m2 of generalized forcing to be able to drive specific droughts (rather than modeled probability distributions) you would have to concentrate the accumulated heat and “park” it over the drought zone.
How do you concentrate heat over a drought zone? First, as TE points out, you have to reduce (or stop entirely) the precipitation. Surface temperature doesn’t increase much while there is still available water to evaporate. Then you probably need a consistent weather pattern/system that prevents a return of precipitation. Poor agricultural practices in some areas (think Dust Bowl) help soil moisture escape at higher rates. Urban runoff and road-related flood control also contribute to reduced water availability (reduced infiltration, etc.)
All this suggests to me that dry conditions can drive drought-related heat at least as much as the other way around. And increased GHGs aren’t even needed for this explanation.
However, there is one thing for which GHGs are absolutely essential: publishing peer-reviewed articles on recent drought trends.
Dr. Sokol wrote:
“A new area of scientific research, known as “extreme event attribution”, has emerged to provide more substantive and quantitative answers.”
As a professor at Lamont-Doherty, all Sokol had to do was walk across the lawn to the engineering department and ask “How do you folks do extreme event attribution?” Imagine his surprise in learning that there has been a well-established protocol for decades!
Attribution to what? Warming or human-induced warming? That attribution problem has yet to be solved, so it is denied. See my http://www.cato.org/blog/nsf-climate-denial?utm_content=buffer2695b&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer
Attribution, she’s a bitch;
Don’t know how, just scratch that itch.
Puff the Magic Climate
Lived by the CO2;
Nature turned and bit him, someplace rich.
========================
Perhaps some examples would enlighten people.
A couple come to mind.
You will know “scientific” papers dealing with attribution are serious when they start attempting to balance the good effects of warming with the bad effects. (In this case, balancing when warming reduces the severity of climate events with the occasions that warming would increase the severity of climate events.) Until then, these papers are simply superficial propaganda.
JD
“Attribution of events to anthropogenic climate change.”
How would they do that when they have no clue of natural climate change.
All they have is climate change, as we have allways had, so how can they discriminate. Ahh, yes models.
There’s no natural climate change according to climate change deniers (warmists). All climate change is anthropogenic. Natural change is called natural climate variability.
Sven Ferdinandsen,
I believe it’s even worse.
Climatologists seem to have forgotten that climate is just the average of past weather.
Weather is the result of natural physical processes within the atmosphere. Nobody has any real clue what effect mankind’s presence has on the weather, either qualitatively, or quantitatively.
Guesses and assumptions abound, but Man’s efforts to change the weather, from rain dances to sacrificing virgins to cloud seeding, has proved to be of uncertain effect.
We are part of Nature. In that sense, any effects we have on the weather are natural.
Cheers.
Words of wisdom from Mike Flynn
“We are part of Nature. In that sense, any effects we have on the weather are natural.”
_____
Maybe Mike Flynn has not thought this through. Couldn’t acts against nature or unnatural acts affect weather?
Max10k,
You wrote –
“Words of wisdom from Mike Flynn
“We are part of Nature. In that sense, any effects we have on the weather are natural.””
Thank you for your compliment. If you don’t understand what I wrote, quote the part you don’t understand, and I’ll do my best to help.
Cheers.
Any honest look at historical weather patterns/climate shows that nothing in the way of those things is outside of historical norms, no matter how much the AGW alarmists screech that they are, or how much the numbers keep getting played with to show a .07 temperature’ record year’.
California, and the recent mild drought that they are having is a perfect example. Research has shown that California, and indeed the whole SW as a whole, has experienced historical droughts that make the current one look pale in comparison. Indeed, the drought in the SW could go on for 100 years, be much worse than it is, and it still wouldn’t be outside historical norms.
http://news.nationalgeographic.com/news/2014/02/140213-california-drought-record-agriculture-pdo-climate/
http://www.nytimes.com/1994/07/19/science/severe-ancient-droughts-a-warning-to-california.html?pagewanted=1
Of course, any attempt at rational conversation with the AGW nutters on historical no0rms of climate is always countered with their numbers fudging to support whatever conclusion they have already reached.
The biggest problem of early attribution is that the likely result is that something important is missed. Attribute to AGW? Attribute that lump to a cyst and you may be right. Or, you may be missing on something a bit more problematic.
I think this is my biggest problem with attribution. “It’s AGW. End of story.” It operates as a bar to further investigation. Further inquiry is only about the influence of AGW.
And judith curry is totally right: it’s not about science. It’s about politics.
Judith Curry is free of politics. Well, I don’t know about that.
No. She isn’t. The nice part about her is she is up front about it.
A few years ago she wrote something that I found to be truly to the point. That climate science is an adjunct for politics and vice versa.
She called it.
The authors are incapable of basic logic. Or they think we are.
Reblogged this on Climate Collections and commented:
JC: “While this report contains no surprises or new assessments, it is more cautious about extreme event attribution than is Myles Allen [link]. That said, I remain highly critical of efforts to attribute extreme weather events to human caused climate change.”