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Thursday, May 1, 2014

About face at WUWT - backing off from denialism

Sou | 6:27 PM Go to the first of 8 comments. Add a comment

The last couple of days have seen a few contradictions at WUWT. Or more properly, about faces. Par for the course for the denialati.


About face number 1 - Neukom2014 is "good science"


First up, I noticed that WUWT-ers at first didn't like the recent paper of Neukom et al which reconstructed surface temperatures of the southern hemisphere over the past 1000 years. Anthony tagged it as "bad science".  Wondering Willis wrote a couple of articles where he decided it was all wrong because Steve McIntyre said it was all wrong, and Willis agreed.  Their argument seems to have been that in their opinion, proxies are more reliable than modern thermometers, which seems a bit silly to me. If a potential proxy didn't reflect temperature as measured by a modern instrument then I'd be inclined to go with the modern instrument - wouldn't you?


It doesn't matter anyway because now Anthony Watts has done an about face. Neukom et al is no longer "bad science". It's very good science. The WUWT about face (archived here) is because of an article in Nature Climate Change by Kim Cobb, which is based on Neukom et al. Anthony Watts' headline is:
New paper finds climate sensitivity to CO2 is lower than previously believed, strong natural variability in Southern Hemisphere

Going by the excerpts published at WUWT, the article doesn't make that finding. It does suggest that climate sensitivity calculations based solely on Northern Hemisphere reconstructions may err on the high side.
If the new reconstruction of Southern Hemisphere temperature is accurate, then estimates of climate sensitivity — the response of global temperature change to a given amount of external radiative forcing — may be lower than those calculated based solely on Northern Hemisphere reconstructions10.  

Given that Anthony has now embraced Neukom et al, which said pretty much the same thing as Kim Cobb wrote, what does that mean for deniers? In particular, does it mean they will let go of their obsession with the medieval warm anomaly, which wasn't in much evidence down south? Does it mean they'll accept estimates of climate sensitivity that are based on global (as opposed to NH only) temperature reconstructions?

This is Figure 3 from the Neukom paper showing extreme warm and cold decadal temperatures. The third chart from the top is the combined northern and southern hemispheres. It's getting mighty hot:




About face number 2 - people can afford climate control

In what is a second about face by the denialiati, it's no longer the case that people will all die of cold when an ice age cometh.  I deduce that from Anthony being co-author of a comment to a paper about deaths from heat extremes in Stockholm County in Sweden. (I wrote about that paper several weeks ago.) Anthony and his co-authors are apparently arguing that people will adapt to hot weather by spending up big on air conditioners, therefore they won't die, unlike people in my home state of Victoria. (More people do die in heat waves in my home state. Anthony's only talking about Sweden. Perhaps people in Sweden are tougher.) And in any case, they argue, what about Urban Heat Islands.

The WUWT article is archived here. Pat'n Chip and Anthony's published comment can be read here. Anthony doesn't link to the reply by Åström and colleagues so I will - you can read it in its entirety I think on Readcube.

The main arguments of Pat'nChip and Anthony are:
  • Stockholm temperatures aren't the same as global temperatures - which is an odd argument because the scientists didn't ever claim it was. It's irrelevant. They threw in "what about UHI" for good measure.
  • People adapt to heat by getting cool.

The main response is (verbatim):
  • The observed [temperature] changes are the result of natural processes, including regional climate variability, and anthropogenic influences, including urbanization.
  • Our data indicate that there is no adaptation to heat extremes on a decadal basis or to the number of heat extremes occurring each year. Although another study observed a reduction in the population health impact of hot and cold extremes over the twentieth century, this decrease should not be confused with adaptation to climatic change.... 
  • Whether future development pathways will continue to increase resilience will also depend on many factors other than climate change. Importantly, it is not appropriate to assume that historic trends will continue, with or without climate change.

There's more in the reply.


Anthony doesn't say what Swedish people do when it gets too hot for the air conditioners to work.  Or what happens when the power companies ration power because there isn't enough to go around with everyone running their new air conditioners full blast.

Anyway if, as Anthony maintains, poor people can afford to buy and run air conditioners when it gets too hot to handle, then they can presumably also afford to buy and run heaters in cold weather.

One thing is that everyone, including Pat'nChip and Anthony Watts are accepting the fact that Sweden is getting hotter. This regional warming is, needless to say, consistent with global warming.




Cobb, Kim M. "Palaeoclimate: A southern misfit." Nature Climate Change 4, no. 5 (2014): 328-329. doi:10.1038/nclimate2219

Neukom, Raphael, Joëlle Gergis, David J. Karoly, Heinz Wanner, Mark Curran, Julie Elbert, Fidel González-Rouco et al. "Inter-hemispheric temperature variability over the past millennium." Nature Climate Change 4, no. 5 (2014): 362-367. doi:10.1038/nclimate2174

Åström, Daniel Oudin, Bertil Forsberg, Kristie L. Ebi, and Joacim Rocklöv. "Attributing mortality from extreme temperatures to climate change in Stockholm, Sweden." Nature Climate Change 3, no. 12 (2013): 1050-1054. DOI: 10.1038/NCLIMATE2022

Knappenberger, Paul, Patrick Michaels, and Anthony Watts. "Adaptation to extreme heat in Stockholm County, Sweden." Nature Climate Change 4, no. 5 (2014): 302-303. doi:10.1038/nclimate2201 (full text here)

Åström, Daniel Oudin, Bertil Forsberg, Kristie L. Ebi, and Joacim Rocklöv. "Reply to'Adaptation to extreme heat in Stockholm County, Sweden'." Nature Climate Change 4, no. 5 (2014): 303-303. doi:10.1038/nclimate2202 (full text here)

8 comments:

  1. Cobb says in the paper:

    "If the new reconstruction of Southern Hemisphere temperature is accurate, then estimates of climate sensitivity - the response of global temperature change to a given amount of external radiative forcing - may be lower than those calculated
    based solely on Northern Hemisphere reconstructions10. Indeed, instrumental
    temperature data suggest that warming in the Northern Hemisphere has been greater than that observed in the Southern Hemisphere over the past two decades (Fig. 1c) - a feature reproduced in the current suite of climate models11. Therefore, this hemispheric asymmetry may be a fundamental feature of the climate system’s response to a change in radiative forcing12, whereby the ocean dominated Southern Hemisphere acts as a buffer of sorts to global temperature change on decadal to centennial timescales. On the other hand, Neukom
    et al. propose that divergent hemispheric temperatures arise from strong natural climate variability in the Southern Hemisphere, and have been a constant feature of the past millennium.

    Cobb simply mentions "external radiative forcing", which is not the same as carbon dioxide 'greenhouse' forcing. Anyone confabulating the two should stop and have a careful think about what they're doing.

    And frankly there's nothing in the rest of the paper that would surprise anyone who's worked in climatology, or even just followed it objectively for a few years. I'm surprised that it was considered to be sufficiently novel or noteworthy as to warrant publication in NCC - at least, with the text commentary in the form that it was printed.

    ReplyDelete
    Replies
    1. A lot of Cobb's article is just a repetition of Neukom14.

      Delete
    2. Congrats, Sou, on spotting Tony's latest self-contradiction.

      @Bernard J., can you expand on why the climate sensitivity to "external radiative forcing" is different to climate sensitivity to Greenhouse gas forcing. I thought that the whole point is that temperature change in response to a forcing is thought to be constant regardless of the origin of the forcing.

      I confess I'm far from expert in this field, so do please put me right on this.

      Delete
    3. Bill.

      There are many forcings (things that affect temperature) and they can act positively or negatively. Solar irradiation, orbital cycles (which affect distant to, and relative land/water exposure to, the sun), cloud cover, aerosols and particulates from natural and anthropogenic sources, all act in addition to 'greenhouse' gases to alter the temperature of the planet.

      Further, because different forcings are (by trivial definition) different, their contribution to climate response (sensitivity) is different - and not immedaite equivalent. So, for example, a doubling of CO2 over the pre-Industrial Revolution atmospheric concentration will result in a forcing that is different if the solar irradiance had been doubled. Likewise, doubling cloud cover or halving surface albedo would have temperature effects (-> sensitivity) that are likely to be different to the sensitivity resulting from doubling pre-Industrial CO2.

      All that the Cobb paper suggests is that climate is less sensitive to natural forcings than previously estimated. Aside from any contensions that may arise from that specific claim, it does not inform much the subject of CO2 sensitivity.

      It's apples and hair brushes...

      Delete
    4. ...orbital cycles (which affect distance to...

      ...immediately...

      [Wince]

      Delete
    5. I've explained that climate sensitivity only weakly depends on the type of forcing applied, which scientists measure by defining a "climate efficacy" for each forcing. Note that Huneeus et al. 2013 finds that the climate sensitivity parameter is independent of the forcing (when measured as an effective radiative forcing).

      Delete
  2. I have to say the reply to the Chip & Pat (are they cartoon chipmunks by any chance?) was fairly devastating.

    ReplyDelete
  3. In some ways it must be nice to start every day with memory as a blank slate, and no worries about what tomorrow may bring.

    ReplyDelete

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