Climate Change, Extreme Weather Linked(?) at Last

by Judith Curry

The title for this post comes from a post at Pew Climate, highlighting a big three-part series featured on  to explain the link between climate change extreme weather.

The series is characterized on the Pew web site as follows:

In a new three-part series featured on Scientific, award-winning science journalist John Carey dissects the science, impacts, and actions to take regarding the record-breaking floods, heat waves, droughts, storms, and wildfires experienced across the United States and the world in the past year. 

Here are the links to the three articles:

  • Part 1 Storm Warnings: Extreme Weather is a Product of Climate Change
  • Part 2  Global Warming and the Science of Extreme Weather
  • Part 3  Our Extreme Future: Predicting and Coping

This is probably the best one-stop shop I’ve seen for the argument that global warming is causing the wide ranging recent spate of extreme events.  It is well written and comprehensive, with plenty of examples of recent weather disasters and authoritative comments from many experts.  The punchline (drum roll . . .) is this statement:

The evidence is in: global warming has caused severe floods, droughts and storms.

So is anyone convinced by these articles?  Below are some deeper perspectives on this issue.

Recent WMO Workshop

The status of our knowledge on attributing extreme events to global warming is summarized by these recommendations from a recent WMO Workshop on Metrics and Methods for Estimation of Extreme Climate Events.

5. General recommendations of the Workshop

The final discussion summarized the recommendations of the BOGs and delivered consolidated general Workshop recommendations as follows:

• WCRP, through its core projects, should enhance efforts to develop improved, high temporal resolution (sub-daily) datasets that can be used to assess changes in extreme rainfall, drought, heat waves, floods, and storms.

• WCRP and in particular, the Working Group on Coupled Modelling, should include in the agenda of model evaluation the focus on the model’s ability to replicate extremes and to better compare model output with observations.

• WCRP core projects (foremost GEWEX and CLIVAR) should place high priority on determining the main phenomena responsible for extremes and improving understanding of the relevant physical processes.

• Special action is required on the development of robust statistical methods for assessing extremes and their uncertainties and on making these tools available for wide-spread use.

• An activity on analysis of extremes utilizing data archived by the WCRP Coupled Model Intercomparison Project should be planned and launched in the near future.

JC’s statement for the Yale360 Forum

And finally, in case you missed it the first time around, here is the statement that I provided to the recent Yale360 Forum on this topic:

Judith Curry, chair of Georgia Institute of Technology’s School of Earth and Atmospheric Sciences.
The substantial interest in attributing extreme weather events to global warming seems rooted in the perceived need for some sort of a disaster to drive public opinion and the political process in the direction of taking action on climate change. However, attempts to attribute individual extreme weather events, or collections of extreme weather events, may be fundamentally ill-posed in the context of the complex climate system, which is characterized by spatiotemporal chaos. There are substantial difficulties and problems associated with attributing changes in the average climate to natural variability versus anthropogenic forcing, which I have argued are oversimplified by the IPCC assessments. Attribution of extreme weather events is further complicated by their dependence on weather regimes and internal multi-decadal oscillations that are simulated poorly by climate models.

I am unconvinced by any of the arguments that I have seen that attributes a single extreme weather event, a cluster of extreme weather events, or statistics of extreme weather events to anthropogenic forcing. Improved analysis of the attribution of extreme weather events requires a substantially improved and longer database of the events. Interpretation of these events in connection with natural climate regimes such as El Nino is needed to increase our understanding of the role of natural climate variability in determining their frequency and intensity. Improved methods of evaluating climate model simulations of distributions of extreme event intensity and frequency in the context of natural variability is needed before any confidence can be placed in inferences about the impact of anthropogenic influences on extreme weather events.

Gavin Schmidt’s take

Note, mine is not just a “skeptics” view; it pretty much agrees with Gavin Schmidt’s RC post last Feb entitled “Going to Extremes.”  An excerpt:

Let’s start with some very basic, but oft-confused points:

  • Not all extremes are the same. Discussions of ‘changes in extremes’ in general without specifying exactly what is being discussed are meaningless. A tornado is an extreme event, but one whose causes, sensitivity to change and impacts have nothing to do with those related to an ice storm, or a heat wave or cold air outbreak or a drought.
  • There is no theory or result that indicates that climate change increases extremes in general. This is a corollary of the previous statement – each kind of extreme needs to be looked at specifically – and often regionally as well.
  • Some extremes will become more common in future (and some less so). We will discuss the specifics below.
  • Attribution of extremes is hard. There are limited observational data to start with, insufficient testing of climate model simulations of extremes, and (so far) limited assessment of model projections.

Forthcoming IPCC Report on Extremes

The IPCC plans to release its special report on Extreme Events in November.  As per the HuffingtonPost:

The chairman of a top U.N. climate panel says it will release a new report in November examining the link between climate change and extreme events like floods and drought that are taking place around the world.

Rajendar Pachauri, chairman of the U.N. Intergovernmental Panel on Climate Change, told reporters Tuesday that the panel has already reported that extreme events are increasing.

He said he didn’t know whether recent Russia fires and floods in the U.S., Pakistan, and Queensland, Australia, would be included “but we certainly will be able to provide a substantial body of knowledge which will tell you what the patterns and trends are, and what are the kinds of adaptation measures that should be adopted to take care of these impacts.”

A focus on adaptation measures with regards to extreme weather events would certainly be welcome.

192 responses to “Climate Change, Extreme Weather Linked(?) at Last

  1. am I glad I stopped my sciam sub long ago!!!

  2. So then Accumulated Cyclone Energy must be up, right?

    • Not unless AGW is determined to be capable of (or already is) taking even a small amount of ACE and concentrating it all into only Cat 5 Storms :-)

  3. A little (lot) off topic, but: Has anyone heard any news from the Berkeley Earth Project? It seems like they have been “weeks away” from publishing results for about 6 or 9 months now.


    • If they actually brought something worthwhile to the temp series, like investigating the adjustments and the bias from most of the thermometers being in human occupied areas, we wouldn’t hear from them for another couple years!! If they are only confirming what is already there, they are overdue. Maybe they are held up arguing over which direction to go??

  4. Theo Goodwin

    I believe that it is impossible to find someone interested in climate science who grew up as a farmer, or who was born before 1950 in the US and enjoyed life in the outdoors, who sees recent weather as extreme. I will not bore you by listing all the cases, just the most humorous one. In 1993, St. Louis suffered a “thousand year flood” that received so much attention that President Bill Clinton had to do a flyover in a helicopter. However, to long term residents of St. Louis, the question was whether this “thousand year flood” was worse than the “thousand year flood of 1982” or the “thousand year flood of 1973?” News media hype and weather hype grow faster than Kudzu.

    • I fit your profile, and I don’t know recent weather is not extreme. I would need to look at the records.

    • I also fit your profile, including having suffered various weather induced wilderness ordeals, but I don’t know what extreme means in this context, because it is meaningless. Far from average events are the norm in weather, as in all chaotic systems.

      It is worth noting that the fact that records continue to be broken merely shows that we do not have a long enough data set. Even if climate were constant, which it isn’t, one could not determine the 100 year flood with 150 years of data, much less the 1000 year flood. Moreover, given that climate varies naturally on decade, century and millennial scales there is no such thing as average climate. In chaos theory this fact is called strange statistics.

      • I never thought of record events being a function of time, being caused by time, because I haven’t noticed a uniform sequence of record events, but I know if there were no more time, there would be no more record events.

      • You will always find some record event, somewhere. That’s the nature of record events.

      • If you look at a plot of record high temps in the US, or anywhere, it looks like saw teeth. July n’s record high may be several degrees higher than July n+1’s. This is just a coincidence due to the short time series, so it is just a matter of time until July n+1 catches up, as it were. (July n is not intrinsically hotter than July n+1.) Assuming the series is stationary and probabilistic, the records highs should all even out over time (technically at the limit). To put it another way, the longer the time series the narrower the confidence interval on the estimated 100 year flood, or the 100 year high temperature.

        Always assuming stationarity, that is, which one should never do with climate. But scale-dependent (or moving) averages makes the question meaningless.

      • Of course I am not claiming that winter highs will equal summer highs. The evening out is seasonal.

      • Theo Goodwin

        Haven’t you just stated a knock down argument to the effect that local newspapers should never run a headline that says “Record High Temperature Yesterday?” Of course, they can run the headline to sell papers but, as you know, what I mean is that there is never a reason related to scientific data sets for running that headline. The headline contains no information about temperature apart from the temperature reading.

      • You are only looking at one saw. If you look at two saws, one for record highs and another for record lows, a different picture emerges, as the following study demonstrates:

        “Relative increase of record high maximum temperatures compared to record low minimum temperatures in the U.S.”

        Click to access 898_Relative%20increase%20of%20record%20high%20maximum%20temperatures.pdf

      • And here’s a link to a graph showing how hot temperature records have been outpacing cold temperature records.

      • M Carey

        It would be interesting to see where the records were set then put a population increase chart over the results.


      • I recall Roy Spenser expressing an interest studying increases in population density around instrument locations, but I think it was to see if the instruments located in areas with the fastest population growth(semi-rural) showed the fastest rises in temperature.

        But relating record highs and record lows to changes in population is another matter. I think you want to see if record lows tended to occur in places that lost or didn’t gain population and record highs tended to occur in places that gained population.

      • M Carey” “hot temperature records have been outpacing cold temperature records”

        Did you read the paper?

        The number of Tmin and Tmax records were 50,000/year in 1950 and have dropped down to 2000 or less in the 2000s.

        The weather is becoming progressively more stable.

      • Since Jan 2001 the continental USA has been cooling at a rate of -4.84 °C / century.

      • maksimovich

        Indeed this is well described in the literature eg Nicolis et al 2006.

        The problem is that the physics (read equations) are not amenable to a brief description ( Kolmogorov-Chaiten complexity) and that complex systems have a phenomenology of there own .

        A good example of the complexity is Ghil et al 2011

      • Didn’t Noah Ark saved animals and people perhaps once in thousands of years?

  5. Has anyone actually looked at Central England Temperatures?

    It used to bounce up and down like a yo-yo with hot years followed by really cold ones and swings of 1.5C in a few year to be not uncommon.

    The difference after 1990 is the really cold years seem to have disappeared.

    So in fact, the fluctuations are incredibly small now.

    They used to be huge.

    2009 to 2010 was the biggest recent drop of 1.28C.
    1995 to 1996 – a drop of 1.32C

    And there are a lot of other examples

    1822 to 1823 – a drop of 1.67C
    1921 to 2922 – a drop of 1.8C

    The weather in the UK has actually been stable. But not really any hotter in terms of highest means … maybe .5C. Its just that there haven’t been the really cold years in between.

    • Bruce

      Yes, in huge detail-it is probably the most examined data set in the world as it is also the oldest. Interestingly the Mean average in 2010 at 8.83C was exactly the same as in the first year of the record in 1659 but there has been a very slow gentle warming trend upwards throughout this period-i.e. 350 years.

      The Met office actually state that there used to be much LESS variability prior to co2 increases. I have asked Julia Slingo very nicely three times to reference me the study that shows this, but answer came there none.


    • One year Changes > 1.5C in CET

      Y1 Y2 Dif
      1739 1740 2.36
      1781 1782 2.19
      1828 1829 2.14
      1878 1879 1.82
      1921 1922 1.8
      1859 1860 1.72
      1798 1799 1.72
      1822 1823 1.67
      1665 1666 -1.58
      1879 1880 -1.67
      1892 1893 -1.8
      1845 1846 -1.89
      1740 1741 -2.46

      • Two year changes >- 1.2

        Could you imagine trying to farm when the temp dropped almost 3C

        Year Y2 Two Year Dif
        1684 1686 2.21
        1686 1688 -2.3
        1690 1692 -1.21
        1693 1695 -1.21
        1725 1727 1.28
        1738 1740 -2.97
        1740 1742 1.52
        1777 1779 1.32
        1799 1801 1.71
        1816 1818 1.97
        1818 1820 -1.29
        1820 1822 1.5
        1823 1825 1.34
        1827 1829 -1.3
        1828 1830 -1.62
        1829 1831 1.93
        1834 1836 -1.61
        1844 1846 1.56
        1855 1857 2.05
        1858 1860 -1.23
        1860 1862 1.28
        1868 1870 -1.4
        1877 1879 -1.75
        1891 1893 1.48
        1893 1895 -1.32
        1909 1911 1.5
        1919 1921 1.99
        1921 1923 -1.39
        1949 1951 -1.35
        1961 1963 -1.47
        1987 1989 1.45

  6. Yes, a lot off topic, but I’m glad you were brave enough to ask anyway, because I’ve been wondering as well, Tim.

    On the subject at hand, in the absence of actual warming to prove their case, alarmists are it seems increasingly desperate to find a way to link extreme (that is bad, very bad) weather with Co2.

    I wonder why they’re never investigating if higher CO2 might be linked to you know, good weather. I highly doubt it of course, but I don’t see why the negative scenario is inherently more likely,. Just thinking out loud…

  7. “global warming has caused severe floods, droughts and storms”

    It’s getting to where even people with the shorter attention spans can smell the desperation.


    • “droughts and storms”

      Less and more rain?


      • Before CO2, every year had the perfect amount of rain/snow for:

        1) Farming
        2) Enjoying Summer Vacations
        3) Skiing
        4) ___________

        Ha ha ha ha ….

  8. Finding evidence to prove your hypothesis is easy. Finding evidence to disprove your hypothesis is hard. What’s that? Your hypothesis can’t be disproven? My, how fortunate for you!

  9. This subject really puzzles me. I must be missing something. Why don’t we know whether extreme events are increasing or not? Surely it should be reasonably easy to find out.

    We have weather stations dotted all over the globe. Surely, as well as recording temperature, they also record wind speed and rainfall. So why isn’t it a trivial exercise to examine all the historical data to see if the weather stations are recording more extreme wind events, more extreme rainfall events, more extreme droughts?

    What am I missing here?

    • James Evans writes “What am I missing here?”

      You are missing absolutely nothing. The articles are in Scientific American. I glanced at them; I could not stand to actually read them. I saw no statistical evidence of any sort. Why Dr. Curry used them as a reference I have no idea. As a reference, so far as I can see, they are absolutely useless.

    • James Evans

      This is the second time I’ve asked this question on this blog, and still the mystery remains. Perhaps I could make it easier by making it a multiple choice question.

      No analysis of extreme weather events in the historical weather station data has been done because:

      1) Actually it has been done, here is a link to the results.
      2) Weather stations don’t record wind speed and rainfall.
      3) The data is not suitable for analysis, because… (please specify.)
      4) The only people with the time and resources to conduct this kind of study (CRU, GISS etc.) have run some rough numbers, and the results don’t come out right. So they have little incentive to continue.
      5) Other (please specify.)

      Pick a number.

      • ferd berple

        4 is the answer. It the results matched the AGW hypothesis, they would be writ large.

      • I think 1 is also true; to a limited extent. But I have no reference. I believe that 50 + years ago, the South African government bought two IBM 650 computers, to keep tabs on extreme weather events in South Africa. They now have an immense amount of data and analysis. This shows, with complete and utter clarity, that, in South Africa, there is no correlation between CO2 and extreme weather events.

    • Pooh, Dixie


  10. Amazing, the longer you watch the weather, the more likely you are to encounter a 100 year event.

    Look at the weather today. Now look at the weather 60 years ago. Pretty much identical.

    The climate variability hasn’t changed. What has changed is the length of time you are watching and the advances in global monitoring.

    If there was a cyclone in the Indian Ocean 60 years ago, no one heard about it. Today it is on CNN labelled “Climate Armageddon” within the hour.

    • What’s totally weird is that when you watch the weather in 100 places, it seems like there is a 100 year event almost every single year on average. If that doesn’t prove the case that AGW causes more extreme events, I don’t know what does, ha ha.

    • ferd

      To illustrate your point, in 1974 – the year of Cyclone Tracy that smashed Darwin, Australia and the year of other major flooding events in Australia – there was extensive flooding in India, on a scale similar to that of Pakistan recently, with similar figures for loss of life and displacement. The BBC and the rest of the worlds media barely mentioned it, if at all.

      • Sorry, my mistake. 1974 was Bangladesh, which was fairly well covered by the media. India was 1953.

  11. David Bailey

    As a non-climatologist, there are many things about the climate debate that seem counter-intuitive.

    For example, there seems no reason to expect that the Earth’s climate was close to a tipping point before industrial CO2 was added, so why would anyone expect the tiny increase in temperatures observed so far to have a disproportionate effect – except in as much, as if you nudge a chaotic system, its behaviour might change abruptly – but on that basis, no change, however tiny, would be acceptable!

    A related question, is why anyone would expect that the global temperature rise so far, of less than 1 C, would have had any significant effects already – after all, the local temperature varies far more than this from year to year?

    Finally, I wonder if anyone has suggested that the extra CO2 could be harmful for any reasons other than its greenhouse effect. It would obviously encourage extra plant growth, which would be useful.

    • ferd berple

      “A related question, is why anyone would expect that the global temperature rise so far, of less than 1 C, would have had any significant effects already – after all, the local temperature varies far more than this from year to year?”

      And by more than that from day to day, and often from hour to hour. Most of us would be hard pressed to detect a 1C change without a thermometer.

      How many would for example could tell if the temperature was 14.5 C or 15.5 C without instruments?

      • The issue is the energy content of the atmosphere, where one degree makes a big difference.

      • John Kannarr

        So if 1934 was the hottest year on record before any recent years, the energy content of the atmosphere then must have been higher, i.e., at or near a “tipping point” (!) and made a “big difference” right then. So what happened?

        And if we have larger than 1.0 C temperature differences during a year or a day, then we must at many times be at one of the threatening tipping points, and yet . . .

      • David Bailey

        Well it makes a big difference just because there is a lot of atmosphere, but that seems beside the point – that energy is spread out over the Earth – how is it supposed to manifest its presence other than by the miniscule rise in temperature?

      • ferd berple

        The energy content of the atmosphere is negligible when compared to the energy budget of the earth. 6 feet of ocean equals the entire atmosphere. It is the oceans which dominate the planet and control the climate. Even the smallest change in the ocean mixing rate dwarfs the projected effects from GHG.

      • If those AGWers can realise this simple fact, we will not be here wasting our time to direct them to proper science and physical properties of CO2, water and air!

    • andrew adams


      AIUI the primary threat posed by extra CO2 other than global warming is ocean acidification.

  12. Fear of global cooling in the 70s became fear of global warming. Realists said global warming hysteria wasn’t ‘cool’ becase the reason for it was simple: ‘it’s the end of the ice age stupid.’

    Now the doomday crowd is concerned about climate change of any kind and now we are no longer concerned with averages but volatility. It’s a creepshow.

    Meanwhile, popular media like ‘The Old Farmers Almanac’ (they at least have stake in getting things right) had the prophetic insight to predicts a colder 2008-9 winter. And, so that came to be.

    The Almanac also predicted global cooling over the next 50 years and they are not alone in forecasting decades of cooler weather. We know from history when they occur, the change in the climate can be very rapid. The UK was not prepared for it and that is why the elderly were burning books last winter to stay warm.

    • ferd berple

      It would make an interesting study. Compare the Farmer’s Almanac to the multi-million dollar climate models and see which displays the greater skill level.

      If the Farmer’s Almanac is performing better than the climate models, that is a quick way to shave millions off the deficit. Replace the million of dollars wasted each year on climate models with the $ 6.95 Farmers Almanac.

  13. I got three paragraphs into the first SciAm article and found this gem:

    “These patterns have caught the attention of scientists at the National Climatic Data Center in Asheville, N.C., part of the National Oceanic and Atmospheric Administration (NOAA). They’ve been following the recent deluges’ stunning radar pictures and growing rainfall totals with concern and intense interest.”

    Here are these hard working, objective scientists, doing their mundane day to day science work when, all of a sudden, severe weather patterns “caught their attention” and piqued their “concern and intense interest.” They weren’t government funded CAGW enthusiasts looking at anything and everything to provide new arguments to support their preconceived view of global warming, no siree.

    And the detailed descriptions of some of the weather events is really precious. I am reminded of the practice of prosecutors in trying a defendant for murder. Where it is stipulated that the victim was murdered, and the only issue is whether the defendant committed the act, the prosecution invariably introduces the most graphic crime scene photos in its possession. They dwell on the photos, posting them on a board or passing them around among the jury. If they can get away with it, they leave the photos out where the jury can see them as long as possible. Everyone pretends that it is just to show the jury the nature of the crime, but everyone involved knows that such pictures inflame a jury, and make it more likely that they will want someone to blame. (Don’t get me wrong, I am a pro-prosecution guy in most ways, but sometimes you have to see things for what they are.)

    I didn’t read the other two articles, I see enough CAGW PR in the rest of the “mainstream” media.

  14. Is it global warming or global climate change or global cooling? Is it global warming because man produces CO2 or is man doomed by man’s production of CO2, irrespective of whatever the temperature may be?

    Is it concern about climate or pollution? Is it liberal or leftist or both? Is it simply a matter of being anti-American … because there is no science in being anti-American; accordingly, if that is what we’re really talking about, I’d be the first to agree that logic and establishing facts based on commonly accepted rules of statistical probability are irrelevant to the argument.

    Is it anti-capitalism or simply being utterly contemptuous of people that work for a living, like truck drivers yaking on CBs, unable to appreciate the intelligence of UN-approved scientists and their supporting cast of Hollywood stars and snakeoil-selling politicians? That’s not science: that is Ward Churchill elitism.

    Us folks in the middle of the political spectrum see it for what it really is. The Leftists want government in everyone’s business, which is why they will even politicize the weather by using silly-science to legitimize whoppers that would make a Piltdown Man hoaxter blush brighter than George Bush passing gas in front of the Queen.

    • John Kannarr

      I suppose the time for us skeptics to get worried is when celebrity alarmists like Al Gore and James Cameron move into 2-room bungalos and disconnect from the power grid and start cycling to their fan events. Otherwise maybe we don’t need to take them very seriously, if they don’t take their own ranting seriously.

  15. It’s amazing that Trenberth continues to persist in this. Gavin Schmidt seems to understand that making a too certain pronouncement can be damaging.

    • I made some tea out of some dried Tarot cards that I had toasted over a burning book of book on Nostradamus and the message revealed in the bottom of the cup was astounding: it said use of the Mayan Calendar to predict the end of the world was prohibited due to the non-payment of yearly royalty payments more than a thousand years ago.

    • Gavin may have some Gypsy/Circus blood. They seem to be more comfortable handling the mark.

    • “Trenbeth” his back radiation of 324W/m2 is hotter than the Sun’s energy reaching the surface at 168W/m2. Yet you feel the warmth of 168W/m2 but you feel 324W/m2 back radiation cool when the clouds shading the Sun’s 168W/m2. I have no clue AMS could publish his article 1997 Annual Global Mean Radiation Energy Budget. Corrupted Science or Pal Review process?

  16. “More to the point, the shortcomings in many science papers used by the IPCC are not usually speciality-related but rather result from ignorance or misuse of advanced (and even standard) statistical methods, computer programming, basic scientific procedures and simple common sense.” (Holland D. Bias and concealment in the IPCC process)

  17. The Scientific American should think twice before publishing articles that might cause global warming deniers to become hysterical.

  18. Is it that extreme weather events can’t possibly be related to changes in average global temperature because the incidence of extreme weather events has been constant throughout history regardless of whether global temperature was rising, falling, or level ?

    • When temperatures were falling were there more extreme weather events?

      Why … maybe so!

      The continental USA is cooling since 2001 at a rate of -4.84 °C / century.


      • Are you claiming recent “extreme weather events” in the USA are are caused by warming over 10 years ago?

        IDIOT ALERT!

      • Sounds like you think (1) the 2001-2011 period in the Continental U.S. witnessed one continuous extreme weather event , (2) the Continental U.S. is not affected by temperatures beyond its borders.

      • (1) You assertion, not mine.

        (2) The effect seems to have been to cool the con. USA

    • Is it that extreme weather events can’t possibly be related to changes in average global temperature because the incidence of extreme weather events has been constant throughout history regardless of whether global temperature was rising, falling, or level ?

      No, it’s because there’s no mechanism by which changes in average global temperatures affects the incidence of extreme weather events.
      There’s always hugely more than enough energy in the system to create extreme events the likes of which modern man has never witnessed, and probably never will. And there always has been, even during the depths of the ice ages.
      Arguing that adding a bit more energy to the system is going to increase the frequency or severity of extreme events is like arguing that a 1″ sea level rise is going to lead to more drownings, or that adding another power station to the grid will make your 11-watt light bulb glow brighter.
      If you really want to find out what influences extreme weather events, I suggest you forget about AGW and look into other areas.

  19. In the words of Henrik Svensmark, “enjoy global warming while it lasts.” Geological history over the last 100,000 tells us that the Earth has mostly been locked in an ice age briefly punctuated by temporary interglacial warming periods. You have to ask yourself why government scientists would purposefully reject observational evidence and adopt a set of beliefs based solely upon unverifiable models. Is it really any wonder why so many scientists started heading for the UN exits years ago? We know what the nominal independent variable is that is key to understanding both global warming and cooling—i.e., climate change. It’s the sun, stupid. That, of course, does not stop the bureaucrats of the secular, socialist government science establishment from sticking one wetted finger in the wind and the other in the public’s eye.

    • Well, it’s probably a conspiracy with world government as it’s goal, and instruments are in on it, fooling people into thinking something is happening when it isn’t. Instruments fool me all the time (e.g., my speedometer telling me I’m doing 75 mph when I know I’m doing only 50 mph).

      • Same thing happened to me. I left my thermometer near the exhaust of an air conditioner and on top of some newly poured asphalt and it told me it was much warmer than it was.

      • We can make adjustments for that so don’t throw away the readings because they’re still perfectly good.

      • Of course … what was I thinking. The waste heat from an a/c unit is always the same and so is the radiant heat from asphalt … all you need is one magic UHI number = .000000000003.

      • They talk about locations of thermometers a lot over at WUWT. You may find this hard to believe, but some people over there think a thermometer located near the exhaust of an a/c or a clothes dryer will show a different rate of temperature change over the years than a thermometer on the other side of the house.

      • Considering that the thermometer is probably been changed in the last 30 years … and the a/c unit has been replaced by a bigger one … and the 19″ TV is now a 40″ plasma … and the a/c only runs when it is warm making the summer temperatures higher and probably never runs in the winter … and the city now has 50,000 people instead of 10,000 and most of them have a/c units … and there are now 100 sq miles of pavement in the town instead of 10 ….

        And then some dishonest weasel at GIS applies the same correction to data back to 1898 even though the last a/c was only purchased in 2007.

        I think the rate of change compared would be different than if it was the same thermometer well away from the house over a grass field with nearby trees an bushes trimmed to a certain level.

        If the rate of change isn’t different between those scenarios then there is something seriously wrong.

      • It’s not nice to assert someone is dishonest (“some dishonest weasel at GIS”) without evidence he is dishonest. It’s similar to lying.

        Accounting for systematic errors is not as difficult as you seem to believe, regardless of whether thermometers are located on different sides of a house in different parts of a county.

        In my example, If the amount of clothes being dried increased over the years as a result of a growing family, a thermometer next to the dryer vent would show more rise in temperature than other thermometers next to the house, a systematic error, and the basis for correcting this error would be temperature records from those other thermometers. Similarly, corrections to systematic errors resulting from non-climatic influences on instruments in urban areas can be based on records from surrounding areas not subject to such influences.

        Satelite-based temperature records are not affected by non-climatic influences. The close agreement between satellite- and surface-based temperature anomalies shows the latter have accounted for systematic errors.

      • Except there is no such agreement between satellite readings and the surface statistical models. HadCru shows relatively steady warming from 1978 to 1997 (when the big ENSO hit) while the UAH sat readings show no warming whatsoever. It is the 78-97 HadCru warming that is suppose to confirm AGW. This is the “last 50 years warming” the IPCC refers to. (After 2001, when the big ENSO subsided, neither HadCru nor UAH shows any warming, but the UAH flat line is warmer that before the ENSO.)

      • Bill Collinge

        This is important. I’m not sure I see quite what you see (ref: Roy Spencer’s blog), but in UAH data I see:

        1978-1997 – Flat or possible warming depending on your interpretation
        1997-2000 – Big bump up
        2001-2009 – Flat or possible slight cooling
        2010-present – Big bump; can’t see follow-on trend yet.

        I would vote we table any discussion about whether the UAH dataset shows warming or not before 1997. I’ve seen this discussed before and I find the argument both ways to be one of minutiae.

        Where on earth or online is the comparison between the two and an intelligent discussion of the discrepancies? Is there one on this blog somewhere that I’ve missed?

        I mean, while we’re all waiting for Berkeley Earth….

      • Anomalies for the four global temperature metrics show good agreement. We can see the agreement in graphs that has been kind enough to prepare.

        In the first graph on the linked page, you can see how all four metrics follow similar upward paths.

        In the last graph, the OLS lines for the sattelite-based RSS anomaly and the two surface-based anomalies are almost identical. The OLS line for the satellite-based UAH anomaly is lower but has the same slope as the other three.

      • A thermometer located near an a/c exhaust would likely have two error mechanisms: 1) the thermometer will probably have been in place long before the a/c unit, and 2) the a/c unit will be in use more during warmer weather, thereby providing a ‘positive feedback’ to the average measurement.
        Also, if your assertion about location not affecting trends is correct then why do we see such large differences in the anomaly graphs for different countries?

      • Australian Greens’ leader Bob Brown has actually called for world government recently as the only way to deal with problems such as CAGW..

      • ferd berple

        That would work! We would then have only one problem to solve. World government.

        Actually, there is a good solution if we consider the following:

        1) We use juries of 12 people chosen “at random” to make the most important life and death decisions for capital crimes.

        2) Anyone that actually wants to be in government should immediately be suspect as the least suitable person for the job.

        So, rather than hold elections, we should simply select 12 people at random every year to run the government. In that was we would get a representative selection and it would be much harder to use money and political campaigns to move corrupt people into positions of power.

  20. The argument is quaint: even though there is controversy about a certain event being influenced by AGW, there is no doubt that the event is a portent of things to come (in 2080).

    Ironically, on the SciAm homepage just below this extreme weather report is an article from last year on a peer-reviewed study:

    Weather or Not?: Last Winter’s Record Snow Driven by Short-Term Meteorologic Patterns, Not Long-Term Climate Change

    A new study helps to explain how extraordinary snowfalls occur despite global warming

    But I would guess that Trenberth would say something like this, as he did with Marty Hoerling’s detailed analysis of the Russian Heat Wave:

    “I completely repudiate Marty—and it doesn’t help to have him saying you can’t attribute the heat wave to climate change,” he says. “What we can say is that, as with Katrina, this would not have happened the same way without global warming.”

    • Ryan,
      In your reading of what Trenberth says, wouldn’t you agree that if he is right, then the average strength and/or number of storms would be higher than in the past? If so, how does your work confirm/repudiate his claim?

      In another blog I’m using the data you’ve posted showing that storm strength is down worldwide to argue that the data doesn’t support Trenberth’s claim… just wondering if you’re of the same opinion.

      • The claim that Trenberth is making was also pushed by Kerry Emanuel. It goes something like this: without global warming, the Gulf of Mexico would have had SSTs and ocean heat content x% lower than otherwise. Therefore, as Katrina developed and moved over the loop current, blowing up to Category 5, it received a global warming enhanced fueling and made landfall a couple days later at a higher intensity that “normal”.

        To my knowledge, this claim has not gained much currency in the TC field overall. 2005 in the North Atlantic was hysterically busy with almost 30 storms, the most since the 1930s. Since the Gulf of Mexico is a quite variable basin in terms of sea-surface temperatures as it is controlled by Gulf Stream output and loop current input, the heat content is also quite variable. I have not seen a study that describes in detail the origin of the anomalously high SSTs in the Gulf. One could initially assume that the conditions that led to the 30 storms during the 2005 season also were favorable for warmer that normal SSTs in the Gulf and elsewhere.

        A climate model scenario of increased SSTs would have to mimic the atmospheric conditions that led both to the anomalous ocean conditions as well as the above normal number of tropical storms. Since “global warming” is on the order of tenths of a degree C, it is likely that it contributed an order of magnitude less to the Katrina situation than natural variability, which we do not understand.

        The current consensus is that global warming has not had a detectable effect on Atlantic or global hurricane intensity, as of yet. It may have shifted around tracks and genesis locations, but all of those attribution studies rely on shoddy best-track data. So, just as with my empirical study, you must constrain your hypotheses and conclusions to what you can prove or disprove. Trenberth’s claims are typically made out of experience and expertise, but may not have been tested rigorously.

  21. Steven Schuman

    After reading the article, I thought the following article would feature a picture of a 100 year old woman in aviator’s goggles with the caption, “Amelia Earhart still alive on deserted island.” I knew this was an excursion from reality when I read about the drought in Maryland where I live. I don’t even recall it being discussed much. My local farm stand is a place where these conversations occur. My denial must be worse than I could ever have imagined.

  22. The reputation of science just keeps getting battered. The blackeyes are so bad, sight has been lost. It’s getting close to needing life support.

  23. I see that John Carey is using Munich Re as a source of evidence. It’s quite mysterious.

  24. It is necessary to reiterate the point that there are many more people around today to experience, observe and report extreme weather, and that they are often living in places that expereience extreme weather BECAUSE they are good places to live. A prime example of this are the millions now living in river, estuarine and sea flood plains which our ancestors would have been wary of.
    Such places have a tendancy to flood and the latter two to be affected by storms.

    Also there seems to be a distinct lack of knowledge amongst some concerning the rich history of those extreme events that were witnessed at the time, or came to light subsequently.

    There have been many instances of storms that have shaped our landscapes or wiped away villages, and hundreds of such events are detailed in a variety of documents. Hubert Lamb does a good job of pulling together those since 1570 and putting them into context in such books as
    “Historic Storms of the North Sea, British Isles and Northwest Europe”

    The cataclysmic events that he records makes me suspect that things were worse then, and that the turbulent weather of periods such as the Little Ice age (which saw great fluctations in temperatures) created the thermal energy needed to unleash these forces.

    So my thesis would be that we see more extreme weather in generally cooler periods- such as the LIA- rather than in the generally warmer weather of the modern era.

    Who do I apply to for funding to study this please?


    • Jack Hughes

      Hi Tony,
      The Anglo-Saxon Chronicle is packed with descriptions of floodes and droghtes and other extreme weather events.

      In fact “fllood” and “drought” are both anglo-saxon words – in contrast with modern words like “computer simulation”.

      • Jack

        I have the Anglo Saxon chronicles AND the climate references of the Byzantine empire-380 to 1450Ad. Theres a lot of climate information in all these! As you rightly say theres a lot of extreme weather events-their frequency or violence is nothing new.


      • What’s the Saxon for ‘it’s worse than we thought!’?

      • RobB said
        “What’s the Saxon for ‘it’s worse than we thought!”
        “You know you said the Normans were coming? Well, they’re here!


      • Look at them bows! Oops. Dies. Or do I have some other conquest in mind? What matters is the AGW conquest, or not.

  25. Since there is nothing in hard science to attribute climate change to human behavior why should this be related to the debate?

    It sells more tickets to the same forces invested in agw in the first place.

    Since much the history is likely to anecdotal it’s going to be like the temp records but much worse. Since the sources are linked to the agenda setting it gets shelf space next to pine cones and ice cores. Another junk science narrative.

    It’s a theme of his;

    What make the assumption in these debates that changing co2 or other human behavior could change forward weather patterns???

  26. Matt Skaggs

    The toolbox is simply empty. Post hoc analysis of an irreproducible event is the weakest way to attempt to elevate a hypothesis to a theory. No one dares make a prediction about the future on this topic beyond “more and bigger events per Hermie” (borrowing from another commenter the reference to Herman Kahn, a Hermie is the elapsed time until a prediction that starts with “in the future” is realized). Models can build a hypothesis, but they cannot turn it into a theory. Empirical testing at the level of complexity of the climate is way beyond our abilities. Even predicting whether the thermometer goes up or down in the future is perilous; trying to link rare, chaotic events that you cannot reproduce to a single pervasive causal factor shows a fundamental lack of understanding about uncertainty and the scientific method.

    • Also, models built on non-reproducible data (i.e. the historical temperature record) are meaningless. This is the fundamental flaw in climate science as it stands today.

      • What are you saying?All historical data is non reproducible.

      • That’s what I’m saying.

      • So how are models built on this data meaningless? All of science is based on past observation.

      • When climate science attempts to put on it’s engineering hat and offer solutions to the supposed problem of AGW, then it needs to play by the same rules as engineers. Structural engineers (elec., mech. and others) base their models on data that can be replicated (tensile, compressive strength of materials, shear, deflection, etc.) and the things they build, based on the output of their models, can be tested to confirm their model’s accuracy. The universe is governed by causal behavior, but it is not deterministic. The climate’s historical record cannot be replicated by independent means because it is a one-time event. This is especially true if one accepts that man’s “volitional” release of CO2 into the atmosphere as having an impact the global temperature. There are things in this universe that we cannot know, period. We can “guess”, but to state that a guess is scientific knowledge, would be wrong.

  27. This SciAm article seems to be heavy on anecdotal evidence, and pretty short on data. A few trends would have been ideal, but apparently no room for that kind of information in a 3 part science magazine article when photos of Katrina have to be fit in.

    The past decade hurricane disaster losses are not above normal, even with Katrina included. See below for US landfalls, global cyclone frequency and cyclone energy trends.

    Being the masterful investigative reporting force they are, no questions to Trenberth about the recent 5 year collapse of cyclone energy since Katrina. Just imagine how much lower it would have been without AGW! Apparently the Pew Center didn’t want that kind of questions asked or answered.

    Is it really that hard to examine rainfall and drought trends and correlate them to CO2 increases and show this? Yes. The data is quite erratic and drawing any conclusions here is simply speculation at best. Let’s not confuse the readers.

    • “This SciAm article seems to be heavy on anecdotal evidence, and pretty short on data.”

      When you add the real “margin of error” of data, watch this debate develop over 30 years what are we really ever left with?

      This field gets compared to our understanding of “gravity”???

      I don’t see JC dismiss this level of bunk either, it’s field far closer in abstraction to string theory (with greatly reduced math skills and overall brain power involved) with little or nothing to support any hint of mitigation rationalization. The overwhelming consensus within the field should support this basic premise but for many incentive flaws the opposite has happened. Selling panic make grants and money. It also lowered the word “science” several bars on the scale of professions.

  28. Hydrological Sciences–Journal–des Sciences Hydrologiques, 53(4) August 2008

    RAPID COMMUNICATION On the credibility of climate predictions
    Department of Water Resources, Faculty of Civil Engineering, National Technical University of Athens, Heroon Polytechneiou 5, GR-157 80 Zographou, Greece

    Abstract Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temperature and precipitation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported.

  29. “The current scientific scene is dominated by the hypothesis that climate is deterministically predictable, combined with the belief that GCMs suitably implement this hypothesis… As this hypothesis and this belief are widely accepted in a variety of scientific disciplines, including hydrology and water resources science, technology and management, and are used as a foundation upon which diverse impact studies are built, there is an urgent need to assess the credibility of climatic models…

    “This study compares observed, long climatic time series with GCM-produced time series in past periods in an attempt to trace elements of falsifiability, which is an important concept in science (according to Popper, 1983, “[a] statement (a theory, a conjecture) has the status of belonging to the empirical sciences if and only if it is falsifiable”).

    “In all examined cases, GCMs generally reproduce the broad climatic behaviours at different geographical locations and the sequence of wet/dry or warm/cold periods at a monthly scale. Specifically, the correlation of modelled time series with historical ones is fair and the resulting coefficient of efficiency seems satisfactory. However, where tested, replacement of the modeled time series with a series of monthly averages (same for all years) resulted in higher efficiency.

    “At the annual and the climatic (30-year) scales, GCM interpolated series are irrelevant to Reality… and, generally, underestimate the variance and the Hurst coefficient of the observed series … An argument that the poor performance applies merely to the point basis of our comparison, whereas aggregation at large spatial scales would show that GCM outputs are credible, is an unproved conjecture and, in our opinion, a false one.”

    (D. KOUTSOYIANNIS, et al., Id @ 682)

  30. Nothing but a statistician is needed to do the analysis of extreme weather event frequency.

    Beyond that one would expect to see some sort of measure of chaos in the climate system that correlates with weather extremes.

    Still yet to see a balanced assessment by a mainstream science journal.

  31. Neville Nicolls’ analysis is that the Australian flooding this spring was due to La Nina. Each of the six rainiest years, going back to 1910, was associated with a spike in the SOI.

    Interestingly, the rainiest period in that record was in the early 1970s, while the globe was cooling.

  32. Given the statistical analysis that is involved, have the authors brought any members of the statistical community in to confirm the statistical methodologies that the authors used?

  33. The latest Pew Center / Scientific American “Linked at Last” claim between (human-caused) climate change and extreme weather events is no more logical than the similar claims made in IPCC AR4 WG1.

    Even if there were a robust statistical correlation (which there is not), this would not provide any evidence for causation.

    And there is a major flaw in the logic: The observations tell us that the late 20th century warming trend stopped around 2001 despite CO2 increase to all-time record levels. At the same time the upper ocean has also stopped warming since ARGO measurements were installed in 2003. So if we were now experiencing more “extreme weather”, it is obviously not coming from recent global warming because there hasn’t been any.

    Judith Curry’s above-stated position makes much more sense.

    All this “linked at last” nonsense is simply an attempt at fear-mongering a public that has already become bored with AGW.


  34. “The inconvenient truth remains…climate is the most complex, coupled, nonlinear, chaotic system known.” ~Stott

  35. Climate Change?

    IPCC claimed “accelerated warming” by comparing the global mean temperature trend for the recent warming phase with a longer period that has a combination of this warming and previous cooling phase. This is a fraud.

    The data shows no accelerated warming as a result of human emission of CO2.

    According to the data, it is true that the global has been warming. However, this warming is not unprecedented.

  36. “Seek and ye shall find” – Matthew 7:7

    Welcome to the new religion. Like the old religion but with.. yanno.. less god.

  37. Climate scientists would be best to use extreme events as examples. If they think floods and fires will increase in the future, they can state that what we see now will have a higher frequency in the future. This is not attribution of the current event, but a valid use of it in a statistical sense.

    • andrew adams

      Indeed, and given that some people argue that the answer to any threat posed by AGW is to adapt to the consequences rather than try to mitigate them it might be useful to examine such events to see how realistic (and costly) such a strategy might be.

    • Jim,

      Bring the AGWers in. The deniers are so lonely here.

    • True. Rising sea levels aren’t dramatic. Extreme events are. Compare road fatalities to 9/1 fatalities to get an idea.

  38. US physics professor:

    Global warming is the greatest and most successful pseudoscientific fraud I have seen in my long life

    A record 3228 comments on one blog article!

  39. Temperature extremes cannot be caused by changes in average global temperature, but temperature extremes can cause changes in average global temperature.

    • How? Isn’t the sum total of the earth’s energy provided by the sun? No matter the number or frequency of “extreme” events, this energy total does not change?

  40. I’m not sure anyone is saying any extremes are caused by changes in average global temperature, but that both are a function of a third factor (such as emissions forcing)
    As for the comment in the article “attribution of extremes is hard” this is certainly true, but thats why we have to infer it from statistics. By analogy, with lung cancer it is hard to work out why a heavy smoker lives to be 95, while someone else dies aged 40, but statistical analysis seems to suggest a link between smoking and lung cancer.

    • They found smokers have a >20x risk of lung cancer, at the 99% confidence level.
      Now here’s the thing – even such a gold-plated result still only suggests a link, and doesn’t prove causation.

      • exactly – it cannot prove INDIVIDUAL causation (which is my point) any proof relates to a POPULATION. Hence the analogy.

      • er, except it’s INDIVIDUALS who get the disease, not the POPULATION. For your analogy to work you’d have to find a malady which came by way of the population, but manifested itself in individuals.
        In any case, my point is that the statistical link between smoking and cancer has been shown to be extremely strong, whereas the same cannot be said of that between emissions and extreme events by any stretch of the imagination.

  41. CLIMATE CHANGE does not mean AGW (or ACC or CO2GW…)!

    This is pathetic anti-science Orwelian language from SA!

    Don’t these people know that the truth will out? Denial?

    • Logical fallacy time again.

      Nature can change climate, therefore man can’t.

      Nature can cause forrest fires, therefore man can’t.

      Nature can freeze water, therefore man can’t.

      • Can you understand simple logic? Why the fallacy? Has the brainwashing been that effective?

      • The only logical fallacy is from your side – man can perhaps theoretically change climate, therefore man does.

  42. Matt Skaggs

    Paul Haynes wrote:
    “As for the comment in the article “attribution of extremes is hard” this is certainly true, but thats why we have to infer it from statistics. By analogy, with lung cancer it is hard to work out why a heavy smoker lives to be 95, while someone else dies aged 40, but statistical analysis seems to suggest a link between smoking and lung cancer.”

    The body of evidence correlating smoking to cancer goes far beyond statistical inference, and it is not at all hard to show how a heavy smoker can live to be 95 (cancer nucleation is a stochastic process). I cannot claim to be familiar with the literature, but there is a simple physical mechanism, and no doubt empirical studies where some unfortunate monkeys got lung cancer. In short, there are plenty of tools in the toolbox used to relate causal factors to disease. Do you have an analogy that is, um, analogous?

    • I think you have missed the analogy because I didn’t make my point clear (and it wasn’t clear which post my comment relates to) so I’ll try to be clearer:

      You can’t prove an individual cancer was caused by smoking – the notion of cause is an inference about populations of smokers and non smokers, even when the evidence seems compelling (as has been well illustrated). There is no simple mechanism, but rather lots of complex ones, hence the notion of genetic susceptibility (for example, CYP2D6, a cytochrome P450 gene, has been shown to activate tobacco smoke-derived nitrosamine, which is carcinogeic), which would make no sense if there was a simple causal mechanism.

      Asking climate scientists to do so about weather events (or those non sceptics who say climate science CAN do this) is asking for the impossible – but this is axactly what some sceptics are asking for. Climate science needs to use the other tools in the toolbox, and develop others, and yes, at present the evidence is much less compelling that the smoke/cancer link.

      My analogy shows that asking for scientists to show a causal link in such cases, without reference to a population of events, is impossible, so don’t ask for the impossible (we don’t even expect this link with cancer/smoking, the “best case” for such a “proven” cause).

      My analogy is not meant to show anything else, but I would add that we shouldn’t expect a simple mechanism to explain the link between CO2 and climate change and those who do, or alternatively, use this fact as the basis for scepticism, misunderstand what climate scientists are actually trying to do.

  43. I submitted the following on this at klimazwiebel:

    “Trenberth is famous for using easily-broken logic, or should be. His infamous ‘energy budget’ has the Earth’s surface emitting more power than is provided by the Sun, the climate’s sole power source. This is known (to competent scientists) as a gross violation of the conservation of energy. I would not trust a scientist (and this includes the ‘97% of all climate scientists’ who are said to back the consensus) who cannot even tell when his theory is violating the conservation of energy, as the consensus greenhouse theory does. The hydrological cycle (including storms) is a mere localized overlay on the primary thermodynamics of the atmosphere, which is shown by the global hydrostatic heat structure, the overall temperature distribution, of the atmosphere (see my blog). I am coining a new climate law: ‘Hydrostatic before hydrologic’. I think when climate science is properly done, it will be found that the number and severity of storms, which are LOCALIZED atmospheric events (or hydrological), are independent of the global, background level of water vapor in the atmosphere (hydrostatic). But climate science may not catch up to the revolution it faces, in my lifetime (say within the next 30 years).”

    • If AMS is a decent organization, it should withdraw his 1997 Global Mean Radiation Budget article.

  44. –> “The body of evidence correlating smoking to cancer goes far beyond statistical inference…”

    “I can tell you that second hand smoke is not a health hazard to anyone and
    never was, and the EPA has always known it. I can tell you that the evidence
    for global warming is far weaker than its proponents would ever admit. I can
    tell you the percentage the US land area that is taken by urbanization,
    including cities and roads, is 5%. I can tell you that the Sahara desert is
    shrinking, and the total ice of Antarctica is increasing. I can tell you that a
    blue-ribbon panel in Science magazine concluded that there is no known
    technology that will enable us to halt the rise of carbon dioxide in the 21st
    century. Not wind, not solar, not even nuclear. The panel concluded a totally
    new technology-like nuclear fusion-was necessary, otherwise nothing could
    be done and in the meantime all efforts would be a waste of time. They said
    that when the UN IPCC reports stated alternative technologies existed that
    could control greenhouse gases, the UN was wrong.

    “I can, with a lot of time, give you the factual basis for these views, and I can
    cite the appropriate journal articles not in whacko magazines, but in the
    most prestigious science journals, such as Science and Nature. But such
    references probably won’t impact more than a handful of you, because the
    beliefs of a religion are not dependent on facts, but rather are matters of
    faith. Unshakeable belief.” ~Michael Chrichton

  45. Interesting, maybe I’ve missed this, I saw Ryan’s comment, and likely most of us know of its existence, but, given the topic, this should be prominent in the discussion.

    Click to access 2011GL047711-pip.pdf

    Now, its behind a paywall, but you can read the abstract and Dr. Maue’s comments here.

    Now, we’ve also already gone through the tornado discussion, and its been determined, in the U.S. at least that the overall trend is down.

    We’ve also seen no increase in temps for a decade. So, blaming any recent weather events on warming is idiocy. More, like the articles quoted above, there’s not statistical analysis comparing past to present. Until there is, I think it is a safe assumption that its because they can’t. Which is really bad considering the alarmist penchant to fudging numbers. All it is, at this moment, is a scary bed time story for children. Until someone else enters the arena that Dr. Ryan Maue has, there really isn’t a discussion. Its hyperbole vs. reality.


  46. Average global temperature may rise or fall, but we shouldn’t expect more record heat or less record cold when the average is rising, and we shouldn’t expect more record cold and less record heat when the average is falling.

    Is that what deniers are saying?

    • –> “Average global temperature may rise or fall…”

      What is the global average temperature? Isn’t temperature an intensive variable? The average of an intensive variable is meaningless. Perhaps you should be more precise, e.g., Based on the method of collecting data comprised of averaging discrete temperature readings taken during the winter at French airports–as adjusted (with adjustments made to the adjusted data)–whereby you then throw away the raw data and extrapolate the adjusted data across regions and seasons to arrive at a predetermined conclusion about what global warming and cooling trends may have been over a given period so as to predict what the future will be?

      • Well yes, the concept of average temperature as calculated for the earth’s surface is completely and utterly meaningless to any sensible scientist. Gerlich and Tscheuschner argued this in a much more technical sense.

        A better sense of “mean” temperature is to distribute the heat in a system over its various masses. Consider a closed system of one liter of water at 0 degrees C with one liter of air at 10 degrees C. A climate scientist can take the mean “surface” temperature and arrive at 5 degrees C. However, the smaller mass of the air contains very little heat energy and when the system equilibrates, the temperature of both will arrive rather close to 0 degrees. We can easily do the math to arrive at a proper figure.

        A more correct computation of “mean” temperature would distribute the total heat energy in the system over all of its masses to arrive at an “equilibrium” mean temperature.

      • –>”A more correct computation of “mean” temperature would …”

        And, for even greater accuracy we should drop the idea of a closed system altogether. Studies have shown that CO2 follows global warming, it does not precede it. And even having some appreciation for the holistic process that are involved in global warming does not mean we will ever be able to effectively model climate change except perhaps in an abstract way such as by way of using the mathematics of chaos.

        The shifting crusts and volcanic eruptions, oscillations of solar activity on multi-Decadel to Centennial and Millennial time scales with variations in gamma radiation and the role of the big planets, Saturn and Jupiter– and a changing North Pole and variations in the magnetosphere– all are a part of a holistic process that is the Earth’s climate.

        EPA government science authoritarians do not control average global temperatures. But we know what does: nominally, it is the sun, stupid.

        And we do have converging explanations that better help us understand the complexity and interconnectedness of natural phenomena comprising global warming. Key elements to a better understanding of climate change are the concepts of a ‘torque’ and the natural power of ‘swirling vortices.’

        These phenomena relate to the role of the atmosphere, the oceans, the Earth’s ‘molten outer core,’ and also the formation of Earth’s magnetic field. Adriano Mazzarella (2008) criticized the GCM modelers reductionist approach because it failed to account for so many of the factors that can only be reckoned with using a holistic approach to global warming.

        One factor is itself just a part but an important part of a larger process. Unlike thinking of climate as the result of CO2 as a single unit, even when thinking in the most simple terms, we can not think of a ‘single unit’ in any more simple way than the ‘Earth’s rotation/sea temperature.’

        Holistically, we see that included in this single unit are changes in ‘atmospheric circulation’ and ‘like a torque,’ variations in atmospheric circulation can in and of themselves cause ‘the Earth’s rotation to decelerate which in turn causes a decrease in sea temperature.’

        It may soon be possible to model this effect mathematically. A study conducted by UCSB researchers (results to be published in the journal Physical Review Letters) involved filling cylinders with water and then heating the water from below and cooling the water from above. This was done to better understand the dynamics of atmospheric circulation and hopefully enable researchers to mathematically model a phenomena observed in nature known as swirling vorticies.

        As applied to Earth science perhaps it won’t be long before, for example, it can be conclusively shown that Trenbreth is never going to find the global warming that he is looking for in the deep recesses of the ocean for the simple reason that it simply is not there. It can’t be there. It’s not there because no matter how much AGW True Believers may wish otherwise global cooling is not proof of global warming.

        Hopefully we can using the mathematics of the UCSB researchers to reveal the obvious–what everyone really knows already–that, given differences in ocean temperature in the real world, cold surface water sinks to the bottom.

        In our water world with the Earth rotating on its axis with warm water at the bottom of the ocean, why will cold water on the top sink? It is the difference in the temperature itself from top to bottom that is a ‘causal factor’ that drives the flow. I think everyone understands the process, i.e., it’s the process we call convection. Let’s hope that the mathematics of ‘swirling natural phenomena’ will help contribute to a global politic where government science authoritarians of a secular, socialist Education Industrial Complex will be prevented from acting like persecutors of Galileo and that anti-capitalist government bureaucracies like the EPA will be prevented from destroying the economy based on the superstition and dogma of communist ideology.

      • “Studies have shown that CO2 follows global warming, it does not precede it.”

        I know. It’s just like how chickens make eggs, but eggs don’t make chickens.

        WAIT ……. it’s like how eggs make chickens, but chickens don’t make eggs if they are roosters.

      • If you don’t understand it, why dont you just ask?

      • Jim, I think I have a handle on it this time.

        “Studies have shown that CO2 follows global warming, it does not precede it.”

        I think this means global warning causes CO2, but CO2 doesn’t cause global warming.

        But that’s like saying debt causes interest charges, but interest charges don’t cause debt.

        A pretty nutty notion if you ask me.

      • M.carey –
        “Studies have shown that CO2 follows global warming, it does not precede it.”

        I think this means global warning causes CO2, but CO2 doesn’t cause global warming.

        That’s an obvious interpretation. Why does the consensus dismiss it? If it’s untrue, science is obligated to produce evidence to that effect. If it’s true, science is obligated to incorporate it into the consensus – regardless of how much of the present “knowledge” it falsifies. Are today’s scientists too lazy – or too immersed in their advocacy – or too committed to a particular story line or………whatever to perform actual investigative science? Appearances are sometimes deceiving, but ….it would appear so.

      • Re Jim Owen’s comment on July 2, 2011 at 8:51 pm


        The science says global warming causes CO2 and the C02 in turn amplifies the warming.

        You could liken it to the way debt causes interest and the interest adds to the debt.

        Warming of oceans releases CO2. Burning fossil fuels releases C02. A long time ago there wasn’t enough burning of fossil fuels to release much C02.

      • M. carey

        Your analogy is flawed, if you look at the 450,000 CO2/temperature record closely.

        There are periods when temperature started to DROP while CO2 levels were ABOVE NORMAL.

        There are periods when temperature started to RISE when CO2 levels were BELOW NORMAL.

        All-in-all, CO2 lagged temperature by several centuries.

        Not much correlation there. And where there is no robust statistical correlation, the case for causation is weak (or non-existent).

        Please ‘splain.


    • Well, I’ll try again…..

      M. I don’t know what deniers are stating. I don’t know any. I do no what Dr. Christy stating in the congressional hearings about how often we should expect “record” events. Perhaps you should brush up on that. Dr. Curry was kind enough to provide the links here at this site. While you’re brushing up, try brushing up on your interpretive math skills as well as interpersonal.

      • In his recent statement to the Subcommittee on Energy and Power, John Christy cites evidence that some specific recent weather extremes can’t be directly attributed to human influence, but he does not claim human influence cannot contribute to weather extremes, as is evidenced in the careful wording of the following two excerpts from his statement:

        “What this means today should be considered a warning – that the climate system has always had within itself the capability of causing devastating events and these will certainly continue with or without human influence.”

        “There will certainly be events in this coming century that exceed the magnitude of extremes measured in the past 130 years in many locations. To put it another way, a large percentage of the worst extremes over the period 1880 to 2100 will occur after 2011 simply by statistical probability without any appeal to human forcing at all.”

        Christy quotes from a NOAA study that attributes the 2010 Russian heat wave to natural causes but doesn’t mention the author’s concern that this heat wave may be a preview of what increases in greenhouse gases could eventually cause.

        “Our assessment indicates that, owing to the mainly natural cause for this heat wave, it is very unlikely that a similar event will recur next summer or in the immediate future (next decade). Whereas this phenomena has been principally related to a natural extreme event, its impacts may very well forebode the impact that a projected warming of surface temperatures could have by the end of the 21st Century due to greenhouse gas increases.”

    • Would you say you get more or less lottery winners during a recession?

  47. Hmm, comment went to spam land?

  48. Kevin Trenberth explains extreme weather events being caused by global warming this week:

  49. Cecil Coupe

    I’m surprised no one has mention the fun ahead. The IPCC has a report due in November on this issue and

    “Rajendar Pachauri, chairman of the U.N. Intergovernmental Panel on Climate Change, told reporters Tuesday that the panel has already reported that extreme events are increasing.”

    Why wait for the report if you know the answer?

    ‘He said he didn’t know whether recent Russia fires and floods in the U.S., Pakistan, and Queensland, Australia, would be included “but we certainly will be able to provide a substantial body of knowledge which will tell you what the patterns and trends are, and what are the kinds of adaptation measures that should be adopted to take care of these impacts.”’

    So somethings happening but you can’t tell us now?

    Will there be a press release emphasizing the worst case and the least practical solution? Will the press release match the SPM? Will the full report be released a month later after further editing and still not match the press release? Will it be free of conflict of information because they implemented their COI policy that they are totally committed to?

    Will the IPCC shoot itself in foot one more time? They can’t have many toes left.

    • More toes than brains!

      But propaganda is an emotional, not an intellectual, exercise.

      Feelings, fears, dangers, insecurities, doubts, . . . that Big Brother can solve.

      • Mr. Oliver K. Manuel, I agree with you. The ‘Stakeholders’, want the unwashed to feel that they have agency, to help them in the coming time of trouble…
        So ‘they’ say.

  50. Except that your ‘take’, Judith, is contextless and therefore misleading; and Gavin’s was not.

    Presumably everyone was already familiar with the linked article. They should be, if they read informed climate science discussion on the internet.
    Let’s look at it more closely and see what else Gavin said e.g. “ these papers demonstrate clearly that the instant pop-attributions we are always being asked for are just not very sensible. It takes an enormous amount of work to do these kinds of tests, and they just can’t be done instantly. As they are done more often though, we will develop a better sense for the kinds of events that we can say something about, and those we can’t.”

    Not only do Gavin (and Trenberth and most other climate scientists) explain in context, and therefore far better than you, why scientists have been reluctant to link single weather events such as those discussed in the research in the linked article, to climate change; they have also explained, in context and far better than you, the reasons it has been a red herring to focus on detection/attribution of specific events. To be clear, such attribution is often demanded by those who want to deny all the evidence of climate change. However, the science shows climate change is happening, and in lay terms, it does not matter to the burden of proof to show attribution of specific events. From the perspective of the evolving science, there are already many scientific indications of an increase in certain types of extreme events due to climate change e.g. heat waves, extreme rainfall intensity; and these are best viewed as combination events (climate change plus natural cycles).

    You add nothing to either the scientific discussion, or the public understanding.

    Unfortunately, you continue to only model how to be selective and inattentive to the issues.

    • Gotta say, Martha – not everyone who makes the attributions of specific extreme events to climate change do so because it is being “demanded” by those who want to deny climate change.

      When you over-state your case, your run into the same problems as those who are on the denier end of the “skeptical unconvinced/denier” spectrum.

    • Martha, go to the attribution category of this web site and see what I have written on this subject. If you can find anyone in the world that has provided more context for this subject, I would like to know about it.

      The brief essay that i included here was my most recent statement, that was solicited by Yale360 with a limit of 250 words.

    • Martha,
      Why are you so imprecise with your words? Perhaps you intentionally call it “climate change” to muddy the water. Heat waves and extreme rainfall intensity are rare events but we do have recorded histories of them. Climate change is a natural process. If you mean something different then you should say so. In order to add to a discussion you need more than to just say someone is speaking out differently than your good ol’ boys climate science club.

      • The Orwelian speak (intentional or not) is crucial for survival of the CO2GW. The water must be clear to see anything.

  51. If I move 100 miles south where the mean temperature is 1 degC warmer, will I experience more extreme weather just like SA and other alarmists say our 1 degC warmer planet is supposedly experiencing right now? In what way is 1 or 2 or 3 degC of GW different from moving 100, 200 or 300 miles south in the northern temperate zone. The public isn’t afraid of moving south because the weather is more extreme there. Why should they be afraid of the extreme weather associated with GW?

    Only two mechanisms for producing extreme weather are discussed by SA: 1) The 1 degC warmer air can hold 7% more moisture. Radiative cooling through the moister air is more difficult. This mechanism certainly applies to moving south. 2) Expansion of the Hadley cell, which – if it actually takes place – should occur in a narrow band of latitudes and not the whole planet. (I personally didn’t find the one paper mentioned at Climate Etc. discussing current evidence for expansion of the Hadley cell persuasive.)

    Many extreme weather events (especially major floods) are associated with a static weather pattern that persists for an unusually long time. Is there any link between such stasis and GW?

  52. It makes no logical sense to me that only warming can cause weather extremes. Weather events are chaotic and chaos is unpredictable and in no way related to trend directions. Cooling is statistically just as likely as warming to result in chaos, except that our 30-odd years of higher quality atmosphere data happen to cover a period of apparent warming. There is no other correlation that could be found by this limited perspective except to attribute everything to warming.

    OTOH, ask a geologist about evidence of weather extremes.

    I don’t think volcanic eruptions, earthquakes or tsunamis count as weather??? Or have they been coopted by the IPCC??

    • tempterrain

      “It makes no logical sense to me that only warming can cause weather extremes.” Except that the weather tends to be more extreme in the tropical regions with their hurricanes, cyclones, typhoons etc. Sea temperature in the Caribbean region is thought to be a key factor in hurricane formation, for example.

      If an increase in extreme weather events (say up to 50% more) were the only consequence of AGW then it might be argued that it was a price worth paying for the convenience of continuing uncontrolled burning of fossil fuels. I’d rate it as the least of the potential adverse effects. But I could be wrong there, and I’d be willing to change my opinion if the evidence was to the contrary.

      • Haven’t seen too many snowstorms and blizzards in tropical areas. Is someone claiming a 50% increase in extreme weather events. I have not yet seen a proper statistical analysis to say there is any demonstrable pattern in weather events and anyway, how a possible few tenths of a degree of temperature could be responsible is rather fanciful.

  53. tempterrain

    You’d have to ask Judith about increasing hurricane frequency and intensity and AGW .She has published papers quantifying the link but its not as high as 50%. Not at present anyway.
    Just read again what I wrote. Carefully this time. Note the sentence starts with “if”.

      • Further to Judith’s post-Katrina hurricane study see this recent Florida State report:

        During the past 6-years since Hurricane Katrina, global tropical cyclone frequency and energy have decreased dramatically, and are currently at near-historical record lows. According to a new peer-reviewed research paper accepted to be published, only 69 tropical storms were observed globally during 2010, the fewest in almost 40-years of reliable records.
        Furthermore, when each storm’s intensity and duration were taken into account, the total global tropical cyclone accumulated energy (ACE) was found to have fallen by half to the lowest level since 1977.
        In his new paper, “Recent historically low global tropical cyclone activity”, Dr. Ryan Maue, a meteorologist from Florida State University, examined the last 40-years of global hurricane records and found strikingly large variability in both tropical cyclone frequency and energy from year-to-year. Since 2007, global tropical cyclone activity has decreased dramatically and has continued at near-historical low levels. Indeed, only 64 tropical cyclones were observed globally in the 12-months from June 2010 – May 2011, nearly 23-storms below average obliterating the previous record low set in 1977.


  54. blouis79Louis79

    Why do so-called scientists continue to describe historical trends and records based on a very limited time scale of convenience? Probably because we only have about 30 years of high quality observational data, but that is no excuse for ignoring long-term geological climate proxies.

  55. blouis79

    The main problem with long-term geological climate proxies is three-fold: the selection of the period studied can amount to no more than cherry-picking a period that tells the desired story, the data themselves are fraught with a high level of uncertainty and the interpretation of the results is highly subjective.

    Real-time observations have problems with the measurement accuracy or built-in biases (such as the impact of the urban heat island effect on global surface temperature),but these are much easier to correct than the many uncertainties associated with paleo-climate data.

    A good example of relatively recent paleo data gone awry is the Medieval Warm Period and Little Ice Age, which were essentially expunged from the historical record by a paleo study that was later shown to be flawed.

    On this basis, I would say that the global surface temperature anomaly record dating back to 1850, with all its known warts and blemishes (e.g. UHI distortion and thermometers next to AC exhausts or airport runways for the land portion, lousy data for most of the SST portion) is still a much better source of data than any paleo study.

    Of course, both are better than model simulations based on theoretical deliberations.


  56. M. carey

    Dr. Christy’s remarks to the US congressional committee, which you quoted, are pretty straightforward.

    What this means today should be considered a warning – that the climate system has always had within itself the capability of causing devastating events and these will certainly continue with or without human influence.

    No real “interpretation” required: the climate system does not need human influence to cause devastating events.

    There will certainly be events in this coming century that exceed the magnitude of extremes measured in the past 130 years in many locations. To put it another way, a large percentage of the worst extremes over the period 1880 to 2100 will occur after 2011 simply by statistical probability without any appeal to human forcing at all.

    Again, pretty straightforward: in a record covering the period 1880-2100, there will undoubtedly be some new records of extremes set in the 89 years after 2011, rather than the 131 years prior to today, simply by statistical probability without the need for any human impact.

    If anyone there was looking for confirmation of Trenberth’s proposed new “null hypothesis” on severe weather events and human influence on climate, they certainly did not get it in these remarks from Christy.


  57. Of course, both are better than model simulations based on theoretical deliberations.

    I think most modellers would agree with you on this point, but models serve a different purpose than geological climate proxies. It is, however, important for modellers to be clear on a number of issues, but certainly:

    1. The model must include a clear statement of what system is being modelled.

    2. The model must have a clear description of the system state and how the state should be interpreted.

  58. “The political consequence of this article seems to be that the simplest solution to global warming is for the Chinese to burn more coal, which they intend to do anyways.” JC

    The Left really needs to hop on this. China uses all the coal they can mine so that leaves sales to Europe of AGW-neutral coal to America. And, this discoery opens up an entirely new filed of exploration for Iran, in lieu of acquiring nuclear capability.

  59. I just want to point out that the framing of this blog post is based on two lines written by editors rather than the authors.

    John Carey’s articles do not contain the purported punchline “The evidence is in: global warming has caused severe floods, droughts and storms.” This comes from the subhead written by an editor. But one of the articles does include the following statement:

    “Whereas it will never be possible to say that any particular event was caused by climate change, new science is teasing out both the contributions that it makes to individual events—and the increase in the odds of extreme weather occurring as a result of climate change.” (

    The title of Judith’s blog post, “Climate Change, Extreme Weather Linked(?) at Last,” is a headline for a blog post at The Energy Collective (the link in Judith’s post does not lead to the Pew Center’s web site as the highlight suggests). I wrote the blog but an editor wrote the headline and I didn’t see it until the article was posted. The take home message of my blog post was clearly stated:

    “The moral of the story is that focusing on the unanswerable question of single-event attribution creates a paradox: Scientists are clear that climate change has caused certain kinds of extreme weather events to occur more frequently, yet they can’t pin climate change to any single event. So, in spite of solid scientific evidence, the public rarely gets the clear message that climate change IS increasing the risk of extreme weather.” (

    Both John Carey’s articles and my writings on this subject are consistent with the WCRP recommendations and other mainstream critiques that Judith lists in her post.

    I recommend viewing the Pew Center’s extreme events web page and actually reading the materials there, including the white paper at the second link below, which says:

    “The fact that 2010 was one of the warmest years on record as well as one of the most disastrous, begs the question: Is global warming causing more extreme weather? The short and simple answer is yes, at least for heat waves and heavy precipitation. But much of the public discussion of this relationship obscures the link behind a misplaced focus on causation of individual weather events. The questions we ask of science are critical: When we ask whether climate change “caused” a particular event, we pose a fundamentally unanswerable question. This fallacy assures that we will often fail to draw connections between individual weather events and climate change, leading us to disregard the real risks of more extreme weather due to global warming.”