Testing the IPCC Climate Forecasts

Of late, there has been a lot of discussion about the validity of the IPCC warming forecasts because global temperatures, particularly when measured by anyone but the GISS, have been flat to declining and have in any case been well under the IPCC median projections. 

There has been a lot of debate about the use of various statistical tests, and how far and for how long temperatures need to run well below the forecast line before the forecasts can be considered to be invalid.  Beyond the statistical arguments, part of the discussion has been about the actual physical properties of the system (is there a time delay?  is heat being stored somewhere?)  Part of the discussion has been just silly  (IPCC defenders have claimed the forecasts had really, really big error bars, such that they can argue the forecasts are still valid while at the same time calling into question their utility).

Roger Pielke offers an alternative approach to validating these forecasts.  For quite a while, he has argued that measuring the changes in ocean heat content is a better way to look for a warming signal than to try to look at a global surface temperature anomaly.  He argues:

Heat, unlike temperature at a single level as used to construct a global average surface temperature trend, is a variable in physics that can be assessed at any time period (i.e. a snapshot) to diagnose the climate system heat content. Temperature  not only has a time lag, but a single level represents an insignificant amount of mass within the climate system.

What he finds is a hell of a lot of missing heat.  In fact, he finds virtually none of the heat that should have been added over the last four years if IPCC estimates of forcing due to CO2 are correct.

  • Well, if anthropogenic global warming truly doesn’t exist I think I’ve determined Gore’s and the alarmist’s fall back strategy: CO2 causes elevated acidity in the ocean harming corals and other shellfish as reported here in The Oregonian today…
    http://www.oregonlive.com/environment/index.ssf/2008/05/carbon_emissions_carbonrich_wa.html
    I posted it on it here earlier…
    http://gorelied.blogspot.com/2008/05/get-ready-heres-way-agw-alarmists-will.html

  • The alarm over ocean acidification has been greatly reduced. The original experiment did not mimic natural processes, so its results were way too high. A recent experiment which involved bubbling the gas through salt water showed little acidification.

    John M Reynolds

  • John Anderson

    When eventually it becomes clear that AGW is not coming to pass, it seems to me that Al Gore and his crowd will claim that all the “hard work” that they did is what reversed the course, and that they are the saviors of mankind.

    And, of course, the media will willing buy in to that lie and propogate it to Joe Public.

    Just my little prediction.

  • jep, Kansas USA

    It’s always been misinformation to claim the IPCC, or anybody else who generates long-term computer climate models, creates forecasts or predictions. Long-term computer climate models produce possible scenarios, based on several what if’s and various assumptions.

    Computer climate models do not output scientific facts. I’ll even posit that those models aren’t really scientific, because they can’t really be verified for decades and unforeseen natural variations, such as a a series of large volcanic eruptions, can’t be accounted for in the models. In a true scientific experiment, one variable can be changed at a time. For world-wide climate, we can only wait and compare the various model outputs with the data as it trickles in over the years. Even then, we can’t really verify if the models are correct or just appear to be correct.

  • “…I’ll even posit that those models aren’t really scientific”

    I saw someone post to that effect on realclimate – the person asked if there was any model or experiment they could do that was in theory falsifiable. The reaction? They basically said that “philosophy of science has advanced in the 60 years since Karl Popper, you know”. Dodging the entire question like a politician, but still claiming to be ‘real’ scientists.

    And yet they wonder why the ‘masses’ aren’t yet convinced by their oh-so persuasive arguments.