Recent Climate Observations: Disagreement With Projections 35


Appearing in Energy and Environment (ee-20-4_7-stockwell2) is a note by myself on a paper by IPCC lead authors Rahmstorf, S., Cazenave A., Church J.A., Hansen J.E., Keeling R.F., Parker D.E., and R.C.J. Somerville, Recent climate observations compared to projections published in Science in 2007.

As shown by 102 citations in Google Scholar already, Rahmstorf et al 2007 has been one of the main references for alarmist calls to action because the “climate system is responding more quickly than the climate models indicate”. Taking the first one off Google:

The strong trends in climate change already evident, the likelihood of further changes occurring, and the increasing scale of potential climate impacts give urgency to addressing agricultural adaptation more coherently. There are …

Adapting agriculture to climate change – pnas.org, SM Howden, JF Soussana, FN Tubiello, N Chhetri, M … Proceedings of the National Academy of Sciences, 2007 – National Acad Sciences.

Respected on-line authors like Peter Gallagher, Mark Lawson and Lucia were concerned with the paper. Lucia attacked the ‘slide and eyeball’ approach. I engaged with Rahmstorf at RealClimate and wrote a number of articles on the uncertainty, until he told me in effect to ‘sod off and publish’. But rather than try to diagnose a sloppy methodology and be ignored, time and evidence has done the job instead. Here is my abstract.

Abstract: The non-linear trend in Rahmstorf et al. [2007] is updated with recent global temperature data. The evidence does not support the basis for their claim that the sensitivity of the climate system has been underestimated.

Its gratifying to read that the authors of the Copenhagen Synthesis Report do not seem to agree with Rahmstorf et al 2007 either, in reference to analysis in a figure that ostensibly used the same method as Rahmstorf et al 2007.

Figure 3 … shows the long-term trend of increasing temperature is clear and the trajectory of atmospheric temperature at the Earth’s surface is proceeding within the range of IPCC projections.

synthesis3

However, five days ago JeanS, a talented data analyst, pointed out an inconsistency in Figure 3 of the synthesis report at Lucia’s in a post, Fishy odors surrounding Figure 3 from “The (Copenhagen) Synthesis Report”, which he illustrated with replications of Figure 3 with different variations on a smoothing parameter. I did some replicating too. It turns out that the global temperature trend had a higher slope than it should have had if it was produced with an 11 year embedding period, as was reported in the caption.

rahm11-141

JeanS queried Stefan about the inconsistency at RealClimate. Five days later his comment was released from moderation and Stefan admitted:

Did you change the filter length from M=11 to M=14 in the temperature graph (Figure 3)?

[Response: Almost correct: we chose M=15.

The reason he gave was essentially to address the same concerns the bloggers had raised about Rahmstorf et al. 2007 in the first place, that Stefan had refused to acknowledge, and are the subject of my paper:

In hindsight, the averaging period of 11 years that we used in the 2007 Science paper was too short to determine a robust climate trend. The 2-sigma error of an 11-year trend is about +/- 0.2 ºC, i.e. as large as the trend itself. Therefore, an 11-year trend is still strongly affected by interannual variability (i.e. weather).

Obviously, I am glad he finally appears to have agreed. But as a later poster pointed out, the misrepresentation of the embedding period in the legend raises questions about the motivation:

Stefan’s inline comment implies that he changed the smoothing method only after he realized that m=11 showed a flattening of the trendline, while m=14 did not. Changing things on the fly like this and leaving the erroneous caption just gives skeptics more ammunition.

Indeed. Of course, Stefan claims it was an innocent error in the figure caption:

[Response: I hadn’t noticed the error in the caption of our graph yet, thanks for drawing my attention to it. I have notified the editors of the report of this mistake. Not sure why a small technical error in the caption would give ammunition to anyone except conspiracy theorists:

This error was not noticed despite the warrant concerning the extensive peer review of the Synthesis Report made in the preface.

This report has been critically reviewed by representatives of the Earth System Science Partnership (ESSP), by the parallel session chairs and co-chairs, and by up to four independent researchers from each IARU university. This extensive review process has been implemented to ensure that the messages contained in the report are solidly and accurately based on the new research produced since the last IPCC Report, and that they faithfully reflect the most recent work of the international climate change research community.

On the relevance, Stefan apparently finds no problem with arbitrarily changing the parameters of the smoothing, and regards the error in the caption as not important:

None of this has anything to do with the smooth trend line or is affected by whether one happens to choose 11-year or 15-year smoothing.

Apparently it does affect the message communicated by the figure enough to want to increase the smoothing from 11 years to 15 years.

So this raises a number of issues:

1. What is to be done with the many sources that already reference Rahmstorf et al 2007, and will in the future, to justify faster actions on controlling emissions, including Australia’s Garnaut Report?

2. Why were the obvious shortcomings of the original article, by a number of lead chapter authors of the IPCC, not pointed out (and defended even) by other members of the climate science community (with a comment in Science say), and only skeptical bloggers noticed or were concerned by it?

3. As Jan Pompe remarks, if temperatures continue to stay flat, is it justified to keep increasing the smoothing period of the trend lines to ensure the appearance of an increasing trend, as Stefan appears to think?

Call me a conspiracy theorist, but when a short smoothing gave a high warming, Rahmstorf and his coauthors were quick to cry ‘the sky is falling’. But when the trend turned down due to random fluctuations, he changed the parameters to stay on message. As Marcellus said, “Something is rotten in the State of Denmark” (Hamlet).

Update: Lucia does a fine job of explaining the history and issues in Source of fishy odor confirmed:
Rahmstorf did change smoothing.

  • Ian Castles

    David,

    In addition to your own contributions and those of Lucia and Peter Gallagher to the discussion of Rahmstorf et al, it’s worth mentioning Mark Lawson’s article in Online Opinion (“Sceptics will have their day”, 17 April 2008, http://www.onlineopinion.com.au/view.asp?article=7244 ), which included the following:

    “Another group, headed by Professor Stefan Rahmstorf of Potsdam University in Germany claimed that the warming is actually at the top end of the range predicted by the Intergovernmental Panel on Climate Change in 2001…

    “It says a lot about the state of debate in this country, that the last claim was picked up and repeated by government policy advisor Professor Ross Garnaut in recent public comments on his efforts to hammer out policy approaches to climate change, and went virtually unquestioned. I later queried Professor Rahmstorf by email: he referred me to material on climate cycles and his paper, which I found to be puzzling. The figures must have been adjusted by a substantial amount for the conclusions to make any sense but the paper barely bothers to mention this. There is a laconic note deep in the paper, which is not otherwise explained or footnoted, that all trend lines are “computed with an embedding period of 11 years”. Given the still patchy knowledge of climate cycles, and that the paper’s conclusions are vastly different from observations, this point should have been discussed in far greater detail.”

    In the light of his correspondence with you and Lawson on this matter, his casual extension of the embedding period from 11 to 15 years (without changing the caption in the Copenhagen Synthesis Report Figure 3) is quite extraordinary.

    • Anonymous

      Ian,
      Is is extraordinary. As JeanS said to me, surely he didn’t think nobody would notice. Thanks for the reference to the fine article that I had forgotten about.
      Cheers

  • Ian Castles

    David,In addition to your own contributions and those of Lucia and Peter Gallagher to the discussion of Rahmstorf et al, it’s worth mentioning Mark Lawson’s article in Online Opinion (“Sceptics will have their day”, 17 April 2008, http://www.onlineopinion.com.au/view.asp?articl… ), which included the following:“Another group, headed by Professor Stefan Rahmstorf of Potsdam University in Germany claimed that the warming is actually at the top end of the range predicted by the Intergovernmental Panel on Climate Change in 2001…“It says a lot about the state of debate in this country, that the last claim was picked up and repeated by government policy advisor Professor Ross Garnaut in recent public comments on his efforts to hammer out policy approaches to climate change, and went virtually unquestioned. I later queried Professor Rahmstorf by email: he referred me to material on climate cycles and his paper, which I found to be puzzling. The figures must have been adjusted by a substantial amount for the conclusions to make any sense but the paper barely bothers to mention this. There is a laconic note deep in the paper, which is not otherwise explained or footnoted, that all trend lines are “computed with an embedding period of 11 years”. Given the still patchy knowledge of climate cycles, and that the paper’s conclusions are vastly different from observations, this point should have been discussed in far greater detail.”In the light of his correspondence with you and Lawson on this matter, his casual extension of the embedding period from 11 to 15 years (without changing the caption in the Copenhagen Synthesis Report Figure 3) is quite extraordinary.

  • davids99us

    Ian,Is is extraordinary. As JeanS said to me, surely he didn't think nobodywould notice. Thanks for the reference to the fine article that I hadforgotten about.Cheers

  • DennisA

    Global Warming has been very kind to Stefan: “German Environmental Aid 2007 media award goes to Stefan Rahmstorf Berlin, 10 December 2007. The 2007 German Environmental Aid environmental award (special award category) will be given today to WBGU member Stefan Rahmstorf.

    The DUH award is an acknowledgement of the climate researcher’s huge commitment to scientifically accurate reporting about human induced climate change and its impacts. (Oh dear!)

    “Since 2000 Stefan Rahmstorf has been Professor of Oceanic Physics in Potsdam and head of the Earth System Analysis research domain at the Potsdam Institute for Climate Impact Research. Prior to this he was a researcher at the New Zealand Oceanographic Institute and at the Institute of Marine Sciences in Kiel (1991-1996).

    In 1999 he received a research award from the American McDonnell Foundation valued at one million dollars.

    He is one of the lead authors of the new UN climate report from the IPCC.”

    He has lots of comments about those who disagree with him here: Taking on Climate Change Myths and Sceptics,
    http://knowledge.allianz.com/en/globalissues/climate_change/global_warming_basics/rahmstorf_climate_sceptics.html

    This is the research section he jointly heads at Potsdam: http://www.pik-potsdam.de/research/research-domains/earth-system-analysis/members

    Two from that list are Greenpeace activists, see here: http://forum.junkscience.com/index.php?topic=288.0

  • DennisA

    Global Warming has been very kind to Stefan: “German Environmental Aid 2007 media award goes to Stefan Rahmstorf Berlin, 10 December 2007. The 2007 German Environmental Aid environmental award (special award category) will be given today to WBGU member Stefan Rahmstorf. The DUH award is an acknowledgement of the climate researcher’s huge commitment to scientifically accurate reporting about human induced climate change and its impacts. (Oh dear!)”Since 2000 Stefan Rahmstorf has been Professor of Oceanic Physics in Potsdam and head of the Earth System Analysis research domain at the Potsdam Institute for Climate Impact Research. Prior to this he was a researcher at the New Zealand Oceanographic Institute and at the Institute of Marine Sciences in Kiel (1991-1996). In 1999 he received a research award from the American McDonnell Foundation valued at one million dollars. He is one of the lead authors of the new UN climate report from the IPCC.” He has lots of comments about those who disagree with him here: Taking on Climate Change Myths and Sceptics,http://knowledge.allianz.com/en/globalissues/cl…This is the research section he jointly heads at Potsdam: http://www.pik-potsdam.de/research/research-dom…Two from that list are Greenpeace activists, see here: http://forum.junkscience.com/index.php?topic=288.0

  • TCO

    Why did you publish in EnE? Why not at least Climate of the Past Discussions?

    • Jean S

      What difference does it make to you? Do you judge also your presents based on the wrappings they come with?

    • TCO

      David: Just read your paper. It is very short and sweet. No big problem with the EnE posting in this case. In other cases, I have often seen a sort of laziness and slackness and poor editing/reviewing (e.g. Loehle) for EnE papers. Also, for more substantive papers, they deserve to be in the abstracted literature. But this one seems fine.

      • Anonymous

        TCO: The compliment is greatly appreciated, particularly as it comes from you. Ideally I would have tried for a comment in Science, but there is a 6 month cut-off on comments on papers.

        • TCO

          Makes sense.

  • TCO

    Why did you publish in EnE? Why not at least Climate of the Past Discussions?

  • Jean S

    What difference does it make to you? Do you judge also your presents based on the wrappings they come with?

  • TCO

    David: Just read your paper. It is very short and sweet. No big problem with the EnE posting in this case. In other cases, I have often seen a sort of laziness and slackness and poor editing/reviewing (e.g. Loehle) for EnE papers. Also, for more substantive papers, they deserve to be in the abstracted literature. But this one seems fine.

  • davids99us

    TCO: The compliment is greatly appreciated, particularly as it comes from you. Ideally I would have tried for a comment in Science, but there is a 6 month cut-off on comments on papers.

  • TCO

    Makes sense.

  • Ian Castles

    David, Your #15514.

    Just to clarify. I wrote to Kevin Hennessy in March 2006 to point out the error in the Whetton et al (2005) CSIRO Research Paper, of which Kevin was a co-author. He replied that “I agree with you. The error will be corrected”, copying his email to eight colleagues at CMAR Aspendale (Greg Ayers, Chris Mitchell, Penny Whetton, Ian Watterson, Roger Jones, Kathleen McInnes, Paul Holper and Simon Torok).

    When the error had not been corrected after about six months, I raised the issue with another co-author of the paper, Roger Jones, with whom I was having an exchange on John Quiggin’s blog. Roger’s reply indicated that there’d been a stuff-up of some kind so I assumed that, the matter having again been brought to notice, a correction would finally be issued. But it hasn’t been.

    The IPCC didn’t come into my correspondence with CSIRO people, because it never occurred to me that a non-peer-reviewed work would be cited in an Assessment Report – but in fact Whetton et al (2005) WAS cited in WGII Chapter 11, of which Kevin Hennessy was Coordinating Lead Author. I would have thought that the fact that the report had been cited by the IPCC strengthened the case for the CSIRO issuing a correction, but I can only assume that the powers-that-be in the CSIRO thought otherwise.

  • Ian Castles

    David, Your #15514.Just to clarify. I wrote to Kevin Hennessy in March 2006 to point out the error in the Whetton et al (2005) CSIRO Research Paper, of which Kevin was a co-author. He replied that “I agree with you. The error will be corrected”, copying his email to eight colleagues at CMAR Aspendale (Greg Ayers, Chris Mitchell, Penny Whetton, Ian Watterson, Roger Jones, Kathleen McInnes, Paul Holper and Simon Torok). When the error had not been corrected after about six months, I raised the issue with another co-author of the paper, Roger Jones, with whom I was having an exchange on John Quiggin’s blog. Roger’s reply indicated that there’d been a stuff-up of some kind so I assumed that, the matter having again been brought to notice, a correction would finally be issued. But it hasn’t been. The IPCC didn’t come into my correspondence with CSIRO people, because it never occurred to me that a non-peer-reviewed work would be cited in an Assessment Report – but in fact Whetton et al (2005) WAS cited in WGII Chapter 11, of which Kevin Hennessy was Coordinating Lead Author. I would have thought that the fact that the report had been cited by the IPCC strengthened the case for the CSIRO issuing a correction, but I can only assume that the powers-that-be in the CSIRO thought otherwise.

  • Ian Castles

    Sorry David,
    I posted a comment below in error. It should have gone to the “More Fishy …” thread on Lucia’s blog.

  • Ian Castles

    Sorry David,I posted a comment below in error. It should have gone to the “More Fishy …” thread on Lucia's blog.

  • Ian Castles

    I meant I posted the comment ABOVE here in error. I’ll get this right in the end.

  • Ian Castles

    I meant I posted the comment ABOVE here in error. I'll get this right in the end.

  • Anonymous

    Ian: Its possible to edit or remove comments after you have submitted them. I’ll remove them comments if you wish.

  • davids99us

    Ian: Its possible to edit or remove comments after you have submitted them. I'll remove them comments if you wish.

  • Ian Castles

    David,

    Yes, please do (and this one too)

  • Ian Castles

    David,Yes, please do (and this one too)

  • Wayne

    Anyone silly enough to think global warming exist, please go to http://www.drroyspencer.com soon.

  • Wayne

    Anyone silly enough to think global warming exist, please go to http://www.drroyspencer.com soon.

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