RP Sr joins the ranks of people telling us its been hot/cold somewhere on earth in some month, but more interestingly points to an essay by Carl Wunsch. Its one of a series, by various worthies, including TIm Palmer. I’m not quite sure what the point is, though… they don’t seem to be much good… if you want to know about GE, youre better off with the wikipedia article.

Wunschs article is particularly stupid (yes I know he’s a great man, that doesn’t mean he doesn’t say stupid things on occaision) that (I paraphrase) concludes that since the ice ages caused big changes in the past we therefore can’t attribute current change to human activity. You can pretty well throw away the entire article except for the end para (and had he done that I wouldn’t be complaining too much), which is:

Thus at bottom, it is very difficult to separate human induced change from natural change, certainly not with the confidence we all seek. In these circumstances, it is essential to remember that the inability to prove human-induced change is not the same thing as a demonstration of its absence. It is probably true that most scientists would assign a very high probability that human-induced change is already strongly present in the climate system, while at the same time agreeing that clear-cut proof is not now available and may not be available for a long-time to come, if ever. Public policy has to be made on the basis of probabilities, not firm proof.

Sure, its very difficult to separate human and natural change. Its very hard to build a nuclear reactor, but people do it. A lot of clever people have spent a long time working on the attribution issue, and the answer is, its us, to some degree of probability. Throwing in “proof” is a red herring – there is no proof outside of maths.


  1. #1 hank

    “Math is hard” as Barbie says. Even without math, climate is hard. People don’t get it. Here’s the research, found while looking for more by Donella Meadows on leverage.

    Mentioned here: http://www.sustainabilityinstitute.org/climate_change/index.html
    Illustration: http://www.opendemocracy.net/content/articles/2455/images/bathtub.gif
    Overall research info here: http://web.mit.edu/jsterman/www/cloudy_skies.html
    Source of quote below here: http://web.mit.edu/jsterman/www/StermanSweeney.pdf

    “Why do people underestimate the time delays in the response of climate to GHG emissions? To explore this question, we presented highly educated adults enrolled in university graduate programmes with descriptions of past greenhouse gas emissions, atmospheric CO2 concentrations, and global mean temperature.

    “Subjects were asked to predict the behavior of CO2 levels and global temperatures in response to changes in human-generated CO2 emissions. No mathematics was required and data was drawn from the non-technical reports of the 2001 UN report of the Intergovernmental Panel on Climate Change (IPCC).

    “We found a widespread misunderstanding of climate change dynamics. Two-thirds of the subjects believed global temperature responds immediately to slight or dramatic changes in CO2 emissions. Still more believed that reducing emissions near current rates would stabilise the climate, when in fact emissions would continue to exceed removal, increasing greenhouse gas concentrations and radiative forcing.

    “Such beliefs make current wait-and-see policies seem entirely logical, but violate basic scientific principles of conservation of matter.”

  2. #2 Ahcuah

    I have never understood this argument about how not fully understanding past climate changes means we cannot know about the current climate change.

    It’s like arguing that, since all the past accidents on a given road were caused by speeding, this accident must also have been caused by speeding. And even when we point out the broken brake line and the lack of skid marks, they still insist that it couldn’t have been brake failure, because all of the other accidents were caused by speeding.

  3. #3 Steve Bloom

    A more useful article could have been constructed using non-climate examples of the need to make decisions based on something less than complete certainty.

  4. #4 Carl Christensen

    I’m starting to think the problem with AGW proponents is they’re letting paleo types define & control the debate, when it seems that we’re actually going into “uncharted territory.”

  5. #5 SteveF

    That Wunsch would be sceptical about GW isn’t exactly a surprise. I think he takes delight in attacking major paradigms, as his Milankovitch and THC papers demonstrate. Both of those papers contain some fascinating arguments, although the alternatives he proposes are rather weak and poorly developed.

  6. #6 Steve Bloom

    I don’t take his views as any more skeptical than the AR4 draft’s conclusion that AGW is “very likely.” He simply makes the obvious point that we need to be prepared to act based on something less than complete certainty, although dwelling on the uncertainty in a popular piece the way he did is counterproductive. Regarding his Milankovitch stuff, I don’t think it’s correct to say he’s attacking the paradigm at all. Rather, he’s working toward a solution.

  7. #7 Roger A. Pielke Sr.

    William- Regarding reporting on “hot/cold somewhere on earth in some month”, and referring to this as “wierd” does not really add to the discussion of climate. Explain what is “wierd” in emphasazing that it is regional climate variability and change that matter to society, and not a global average surface temperature trend.

    If you are going to trivialize such reporting, which is placed in context on my weblog (e.g. see http://climatesci.atmos.colostate.edu/2006/08/03/rare-snowfall-across-south-africa/), you should also comment on all of the hype in the media regarding the recent heat wave (e.g. see http://www.timesonline.co.uk/article/0,,2087-2291760,00.html).

    [I expect the mass media to do silly things like thinking any one months weather says anything useful about global warming or long term trends. I'm surprised when respected climatologists do it. Reporting any one months, or one seasons, weather does nothing to advance the discussion of climate -W]

  8. #8 Carl Christensen

    it’s a case of “damned if you do — damned if you don’t.” If there was incontrovertible evidence of anthropogenic global warming happening over the next hundred years, but we happened to be in the middle of a 5-year “cool period” — you know damn well the Republicans & their ilk would be making jokes & screeching about “gee so much for global warming etc.” But if you take a short, hot trend and insinuate AGW, they’ll screech that you’re alarmist.

  9. #9 Dano


    I’d discuss your comment in context on your blog, but apparently I’ve been banned [too much me taking apart the see-oh-too mendacity that appears there without comment?], so here it is:


    True Roger.

    Some places may get cooler in the future. Having clear information in the media will allow fewer obfuscations in the public debate.






  10. #10 Eli Rabett

    Ah yes, but I searched “heat wave” and “cold wave” on google. 45.9 million for the former, 0.4 million for the latter. Clear evidence of the local effects from global warming (with a hat tip to Baliunas and Soon)

  11. #11 Adam

    It doesn’t really affect the outcome, but the phrase “cold snap” gets 2,070,000. Just thought I’d mention it before Peiser does. ;)

  12. #12 Eli Rabett

    Ah, but Adam, a snap is only half as long as a wave, so we have to divide that by 2:)

  13. #13 Adam

    And if we’re going to add “cold spell” (divide by 1.5) we’ll need to add “hot spell” too…nope I can’t see any way of making the two figures close.

  14. #14 Hank Roberts

    “… White Magic Spells currently available … the Protection from Cold spell cast in this way protects the …
    http://www.heroquest.org/rules2005/magic/whiteall.htm ….”