IPCC to Once Again Illustrate Climate Model Failings in AR5 Summary for Policymakers

The IPCC appears to be ready to make the same presentation of climate model failures as they have in past reports.  Figure SPM.5 from the leaked draft of the Summary for Policymakers for the IPCC’s 5th Assessment Report shows the same fatally flawed tactic of presenting model simulations based on only natural (solar and volcanic aerosol) forcings versus those based on anthropogenic and natural forcings.  It looks as though the IPCC is content with highlighting the models’ failures to properly simulate natural coupled ocean-atmosphere processes that can cause surface temperatures to warm — or to stop that warming without notice.

Small Fig. SPM.5

Figure SPM.5 from the leaked draft of the Summary for Policymakers for the IPCC’s 5th Assessment Report

Larger copy is here.

Additionally, note the (blue) ocean heat content graphs. They’re showing ocean heat content data for the Southern Ocean as far back as the 1970s, yet there are only a handful of temperature and salinity samples at depth there before the start of the ARGO era in 2003.  Consider this too: there are only a few sea surface temperature measurements in the Southern Ocean before the satellite era of sea surface temperature data, which started in 1982.  Altogether, there is little observations-based ocean temperature data before those benchmarks in the Southern Hemisphere, south of about 30S.

And I’m sure you can find other flaws in that bogus illustration.

Once again, the IPCC is presenting misleading illustrations.  No surprise there.

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About Bob Tisdale

Research interest: the long-term aftereffects of El Niño and La Nina events on global sea surface temperature and ocean heat content. Author of the ebook Who Turned on the Heat? and regular contributor at WattsUpWithThat.
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10 Responses to IPCC to Once Again Illustrate Climate Model Failings in AR5 Summary for Policymakers

  1. Gary says:

    97% guesswork? 😉

    The same illustration showing actual data coverage would have greater impact than words.

  2. MJFriesen says:

    re: “misleading illustrations” – points taken eg around ocean heat data being lacking going back decades due to lack of operational ARGO system…

    But, how about what I would consider the “main” graph. That would be the Global Average, Land and Ocean Surface Temperature at the bottom.

    There we have models without anthro forcing, being blue. Models with forcing, that being pink/red. And actuals, being black.

    1) I am assuming that if I had the HADCRUT or GISS anomalies I could do decadal averaging and reproduce the BLACK line.
    2) Based on your previous posts about how to download CMIP5 data (still need to work through it, but by the way it is an excellent step by step because I’ve had the same questions about the model vs observations as others in the last few weeks and have wanted to get my hands dirty with some data), I am assuming one can get the CMIP5 average ensemble output for:
    a) the models without anthro forcing (and take decadal averages and do similar graphs
    b) the models with anthro forcing (and take decadal averages and do similar graphs)

    So if we can do 1, 2a and 2b we could reproduce that “main” graph. Can we then still consider that main graph “misleading” and if so, why?

  3. Bob Tisdale says:

    MJFriesen says: “….I am assuming one can get the CMIP5 average ensemble output for:
    a) the models without anthro forcing (and take decadal averages and do similar graphs
    b) the models with anthro forcing (and take decadal averages and do similar graphs)…”

    Sorry, MJFriesen, the only model outputs available through the KNMI Climate Explorer are the full simulations with natural + anthropogenic forcings. The models outputs from the runs without manmade greenhouse forcings are not available.

    Regards

  4. MJFriesen says:

    OK, thank you Bob.

    So one could do (were one so inclined) the full simulation (natural + anthro) vs observations and check the replicability of the graph, purely from KNMI information.

    Probably to do more drill down, one would have to get into the actual data/results coordinated by the CMIP5 groups, for example, at: http://cmip.llnl.gov/cmip5/data_faq.html ? I haven’t been very far down that rabbit hole and am just trying to become with the acronyms of how the various model runs are named & numbered. For your research, have you looked into getting CMIP5 results other than from KNMI?

  5. Bob Tisdale says:

    MJFriesen says: “For your research, have you looked into getting CMIP5 results other than from KNMI?”

    Nope. KNMI provides the outputs in an easy-to-use format. That way anyone can replicate my findings.

    Regards

  6. MJFriesen says:

    Yes, I can see the KNMI is a very useable tool compared to the relatively cryptic discussions on the “official” CMIP5 website.

    I think I’ll wait until the IPCC report is released, which seems like might be Sep 30 for the first part. It is possible the graph you posted from the earlier version (eg “Figure SPM.5”) may be changed in some way (who knows what the behind closed doors interaction will be between the politicians and the panel authors).

    At least from the draft, it looks like they footnote references to the details in the Supplementary Material, for any data they’ve used within their charts. Hopefully this continues with the final release. At that point, I may try to get my hands dirty with independent confirmation of the SPM graphs. I am sure I won’t be alone in that.

  7. Chris says:

    Hi Bob,

    Sorry I’m kind of new to this – what is the problem with that figure? I don’t get the “models’ failures to properly simulate natural coupled ocean-atmosphere processes that can cause surface temperatures to warm”. What is going on?

  8. Bob Tisdale says:

    Hi Chris:

    First, the illustration: The IPCC is using their tired old “good” vs “bad” models illustrations. They are attempting to show that mankind is responsible for the warming over the past few decades. And to do this, they are comparing two types of model runs: (1) models forced by natural factors (variations in the solar cycle and volcanic aerosols), the “bad” models. The bad models show no warming over the past 30 years. And (2) models forced by natural factors AND by anthropogenic factors (like manmade greenhouse gases), the good models. The “good” models show the warming.

    The ridiculous part: the models are tuned so that they will warm over the past 30 years (or so) when they are forced by the natural AND manmade factors, so the models are expected to do a reasonable job with those inputs. And because of their tuning, they won’t (can’t) show the warming without the manmade factors—thus the “bad” models. It’s a self-fulfilling fantasy. It’s also very misleading as you can tell.

    Second, coupled ocean-atmosphere processes: There are a number of well-known coupled ocean atmosphere processes that can cause long-term warming of the global oceans—and in turn land surface air temperatures. El Niño and La Niña events in the tropical Pacific are examples, but they’re quite complex…and very interesting though. We’ll put those aside for a moment.

    There is also a more long-term mode of natural variability that presents itself in the sea surface temperatures of the North Atlantic. It’s called the Atlantic Multidecadal Oscillation. Sea surface temperatures in the North Atlantic can warm at more than twice the rate of the global oceans for two to three decades, contributing extra to global warming, and one of those warming periods appears to have recently ended. (It’s tough to tell because the “cycles” aren’t always uniform in length or strength.) The sea surface temperatures of the North Atlantic can also warm more slowly than the rest of the global oceans (suppressing the warming) and actually cool for multidecadal periods.

    Climate models can’t simulate the Atlantic Multidecadal Oscillation. I showed that in a recent blog post. See the discussion just after Figure 2 in the following post:
    https://bobtisdale.wordpress.com/2013/10/03/questions-the-media-should-be-asking-the-ipcc-the-hiatus-in-warming/
    And that ties back to the illustration that’s the subject of this post.

    And if you’re feeling really adventurous, Chris, here’s a link to an illustrated essay about the natural warming of the global oceans (discussing the long-tern effects of El Niño and La Niña events on sea surface temperatures and ocean heat content). It’s a 42MB pdf file:
    https://bobtisdale.files.wordpress.com/2013/01/the-manmade-global-warming-challenge.pdf

    Stop back when you have more questions.

    Regards

    PS: I’m signing off for tonight. So I won’t be answering any more questions until tomorrow.

  9. Chris says:

    Hi Bob,

    Thanks for the reply, you’ve given me a lot to read! Just a quick question, do you have any articles, or other references, on how they tune the models?

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