October 28, 2008 | Graham

More on climate sensitivity

The climate science is slowly blowing more and more holes in the IPCC anthropogenic warming case, but just as with any other bubble, the bulls are at their most vigorous just as their case starts to collapse. The result? You won’t hear references to the collapse around the water cooler, anymore than people were telling you a few months ago that the financial system was going to crash.
The major climate change issue has never been whether CO2 is a a greenhouse gas, but how sensitive climate is to it. The Vostok ice core samples were telling us that CO2 is not the major shaper of climate 10 years ago. The IPCC models say that it is. We’re starting to get some real world modern observations that give us a better handle on climate sensitivity.
Roy Spencer has impeccable credentials and is doing really interesting work with the data from the Aqua satellite. His latest paper demonstrates a relationship between the Pacific Decadal Oscillation (PDO) and climate change. His thesis is that this is amplified by changes in cloud cover. His conclusion is suitably modest, given the triumphalism (and nihilism) of the IPCC:

The evidence continues to mount that the IPCC models are too sensitive, and therefore produce too much global warming. If climate sensitivity is indeed considerably less than the IPCC claims it to be, then increasing CO2 alone can not explain recent global warming. The evidence presented here suggests that most of that warming might well have been caused by cloud changes associated with a natural mode of climate variability: the Pacific Decadal Oscillation.
The IPCC has simply assumed that mechanisms of climate change like that addressed here do not exist. But that assumption is quite arbitrary and, as shown here, very likely wrong. My use of only PDO-forced variations in the Earth’s radiative energy budget to explain two-thirds of the global warming trend is no less biased than the IPCC’s use of carbon dioxide to explain global warming without accounting for natural climate variability. If any IPCC scientists would like to dispute that claim, please e-mail me at roy.spencer (at) nsstc.uah.edu.
If the PDO has recently entered into a new, negative phase, then we can expect that global average temperatures, which haven’t risen for at least seven years now, could actually start to fall in the coming years. The recovery of Arctic sea ice now underway might be an early sign that this is indeed happening.

Another paper (hat tip to Anthony Watts) suggests that the hole in the ozone layer may be due to cosmic radiation. We’ll know if the theory is any good later this month because it makes a prediction for this period. If the prediction fails then I don’t have to revise my view on CFCs.
If it does hold true, then the people at the Australian Bureau of Meteorology have another possible explanation for their theories on southward shifts of climate patterns. This is supposed to be due to the hole in the ozone layer making it colder at the South Pole and sucking weather patterns further south. I have problems with cold air pulling, rather than pushing, hot air, but assuming they are right, then the culprit for this may be outside the atmosphere, rather than inside.
If I do have to revise my views on CFCs then so should David Michaels. He’s the latest global warming conspiracist, who joins such Australian “luminaries” as John Quiggin and Tim Lambert, and now apparently Philip Adams (who gave him an approving interview last night), in drawing a link between tobacco lobbyists and climate skeptics. CFCs and their effect on ozone are a stepping stone in the “proof”.
We’ll see. It certainly looked to me at the time that CFCs were implicated in the expansion of the ozone hole. Some of the global warming skeptics disagreed at the time, most notably Fred Singer, who Lambert and Quiggintry to portray as a tobacco lobbyist. Only three more sleeps.
But whatever the truth of the ozone hole, it is surely outrageous to label those who question the IPCC catechism as being linked to those who say smoking doesn’t cause lung cancer.

Posted by Graham at 9:07 pm | Comments (10) |
Filed under: Environment


  1. Ozone chemistry isn’t settled science either:
    New Research Challenges Established Ozone Hole Theory:

    Comment by Paul Biggs — October 28, 2008 @ 10:48 pm

  2. There is a typo in the second last paragraph, Quiggin and try should be separated.
    Or perhaps it’s a portmanteau.

    Comment by Pedro S — October 29, 2008 @ 7:55 am

  3. Thanks Pedro, I’ll leave the typo there seeing it would make your comment unintelligible if I didn’t.
    Paul, that link appears to say that destruction of CFCs should occur more slowly than we previously believed. Is there potentially a larger problem? Or am I missing something?

    Comment by Graham Young — October 29, 2008 @ 8:18 am

  4. All quite interesting and worthy of debate and further data. On a wider scale, complex systems such as climate will show big swings before they bifurcate completely into a new range of behaviours. Like the current stock market, perhaps.
    I maintain the picture being offered of climate is still too small, and overall carrying capacity and environmental degradation of critical systems (such as fisheries, forrests and soil) has to be considered.
    Perhaps a more useful indicator of how sustainably we are managing the planet is the stats on starvation, which provide a more holistic assessment of where we are heading. What do those stats say? I’ll have a look…

    Comment by Ronda — October 30, 2008 @ 12:25 am

  5. It seems that the more the walls of man-made GW come down, the more the Warmistas push out spin.
    Following the 41 inconvenient lies in “An Inconvenient Truth,” our own Cate Blanchett has premiered a movie featuring 40 disciples of Gore.
    Also Prince Charles – in Japan – has said not to worry about the Financial Crunch but to worry about the Global Warming Crunch.
    He’s a real worry!

    Comment by Geoffrey Brown — October 30, 2008 @ 9:04 am

  6. What I find interesting and concerning in the climate change skeptics position is the fact that they generally agree that ‘The major climate change issue has never been whether CO2 is a a greenhouse gas’. They infer from this that it might contribute to greenhouse but not yet, maybe some day down the track. Yes, eating fatty meat pies three times a day won’t kill you…not yet. I urge people to side with the skeptics and sit on their spreading buts and do nothing. After all, God will save us won’t He?

    Comment by david akenson — October 30, 2008 @ 9:27 am

  7. David
    Co2 is a green house gas √
    Water Vapour is a greenhouse gas √
    Ice core samples from Vostok and greenland show that the rise in Co2 FOLLOWS global warming. √
    Excess Meat pies and doughnuts make you fat √
    If Co2 follows warming and we have now had stasis or cooling since 1998, I’ll dodge the meat pies but order some heaters.

    Comment by Geoff Brown — October 30, 2008 @ 2:33 pm

  8. Geoff,
    You know perfectly well that climate change and weather are different things. Sure, short term spikes in temperature will be felt, but the overall trend is toward warmer climate. Again, do nothing and then make your apologies when you find out how wrong you were. The cost of doing something is a good deal less than doing nothing. I would prefer to have egg on my face than sunburt skin.

    Comment by david akenson — October 30, 2008 @ 6:23 pm

  9. By Professor Don Easterbrook, Western Washington University says
    “the global climate has not warmed 1F as forecast by the IPCC but has cooled slightly until 2007-08 when global temperatures turned sharply downward. In 2008, NASA satellite imagery confirmed that the Pacific Ocean had switched from the warm mode it had been in since 1977 to its cool mode, similar to that of the 1945-1977 global cooling period. The shift strongly suggests that the next several decades will be cooler, not warmer as predicted by the IPCC”

    Comment by Geoff Brown — October 31, 2008 @ 5:04 pm

  10. Geoff, a few points: Firstly, Western Washington universtiy does not have a PhD program and so research at such a university may lack the expertise necessary to contribute to this debate in a substantial way. I could quote obscure phrenologists who demonstrate a link between the shape of the skull and crimal tendencies, but that does not make the science compelling or correct. Secondly, You might add to your greenhouse gas list, more than otherwise harmless water vapour: methane, CFC’s HFC’s and the like, but the point is; if the science is correct, that the link exists, and we couldn’t live on this planet without such a connection, then the greenhouse effect, distorted by human activity, will continue to trap long wave radiation and increasingly feed back into the system until we throw our hands up and bend to our knees.

    Comment by david akenson — November 2, 2008 @ 12:37 pm

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