McIntyre also demonstrates why the currently-favored excuse for the 'pause' of "the oceans ate my global warming" is unsupportable.
Two Minutes to Midnight
Excerpts:
There is much in the news about how IPCC will handle the growing discrepancy between models and observations – long an issue at skeptic blogs. According to BBC News, a Dutch participant says that “governments are demanding a clear explanation” of the discrepancy. On the other hand, Der Spiegel reports:
German ministries insist that it is important not to detract from the effectiveness of climate change warnings by discussing the past 15 years’ lack of global warming. Doing so, they say, would result in a loss of the support necessary for pursuing rigorous climate policies.
According to Der Spiegal (h/t Judy Curry), Joachim Marotzke, has promised that the IPCC will “address this subject head-on”. Troublingly, Marotzke felt it necessary to add that “climate researchers have an obligation not to environmental policy but to the truth”.
Unfortunately, as Judy Curry recently observed, it is now two minutes to midnight in the IPCC timetable. It is now far too late to attempt to craft an assessment of a complicated issue.
Efforts to craft an assessment on the run are further complicated by past failures and neglect both by IPCC and the wider climate science community. In its two Draft Reports sent to external scientific review, while IPCC mostly evaded the problem, its perfunctory assessment of the developing discrepancy between models and observations, such as it was, included major errors and misrepresentations, all tending in the direction of minimizing the issue.
IPCC has a further dilemma in coopering up an assessment on the run. Although the topic is obviously an important one, it received negligible coverage in academic literature, especially prior to the IPCC publication cutoff date, and the few relevant peer-reviewed articles (e.g. Easterling and Wehner 2009; Knight et al 2009) are unconvincing.
The IPCC assessment has also been compromised by gatekeeping by fellow-traveler journal editors, who have routinely rejected skeptic articles on the discrepancy between models and observations or pointing out the weaknesses of articles now relied upon by IPCC. Despite exposure of these practices in Climategate, little has changed. Had the skeptic articles been published (as they ought to have been), the resulting debate would have been more robust and IPCC would have had more to draw on its present assessment dilemma. As it is, IPCC is surely in a well-earned quandary.
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The [temperature] observations through 2010 fall within the upper range of the TAR projections (IPCC, 2001) and roughly in the middle of the AR4 model results.
This assertion was flat-out untrue. Their Figure 1.4 (see below), which purported to support this claim, was not derived from peer reviewed literature and was botched. They misplaced observations relative to AR4 model projections (presumably due to an error in transposing reference periods).
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In a recent article in National Post, Ross
McKitrick pointed out the inconsistency between IPCC’s language and its graphic, acidly observing:
The IPCC must take everybody for fools. Its own graph shows that observed temperatures are not within the uncertainty range of projections; they have fallen below the bottom of the entire span.
Reiner Grundmann at Klimazweibel also recently drew attention to the discrepancy in this graphic (citing McKitrick).
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The criticisms in both the Liljegren comment and the Michaels et al submission were valid at the time and remain valid today. Many of their criticisms surfaced recently in Fyfe et al 2013, though this did not rebut Easterling and Wehner 2009 or Knight et al 2009 as directly. Fyfe et al 2013 was not published until after the IPCC deadline and, thus, Easterling and Wehner 2009 and Knight et al 2009 remained unrebutted in academic journals and were essentially all that was in the cupboard for the IPCC assessment.
Ross and I had experienced something similar in our comment on Santer et al 2008, which was likewise rejected by the original journal (International Journal of Climatology.) A couple of years later, Ross managed to get much of this material into print as McKitrick et al 2010. However, in the meantime, Santer et al 2008 continued to be cited in assessment reports. As an ironic footnote to our earlier controversy, AR5 now cites McKitrick et al 2010 and concedes that the discrepancy between models and observations in the tropical troposphere is unresolved.
The Problem Re-stated
IPCC’s Government Draft attempt to frame the discrepancy between models and observations as due to “natural variability” is ultimately a statistical problem – never a strong point of IPCC authors. Further, as noted above, the statistical analysis in the Government Draft purporting to support “natural variability” is not drawn from previously published literature, but was developed within the chapter (despite frequent protestations that IPCC does not itself do research.)
IPCC conceded in the Government Draft that there has been a 15-year “hiatus” (their term) in temperature increase, but assert that “individual decades” of hiatus are also “exhibited” in climate models, during which time the “energy budget is balanced” by energy uptake in the deep ocean:
However, climate models exhibit individual decades of GMST trend hiatus even during a prolonged phase of energy uptake of the climate system (e. g., Figure 9.8, (Easterling and Wehner, 2009; Knight et al., 2009)), in which case the energy budget would be balanced by increasing subsurface-ocean heat uptake (Meehl et al., 2011; Guemas et al., 2013; Meehl et al., 2013a).
However, pointing to the deep ocean doesn’t actually resolve the discrepancy between models and observations, since, as Hans von Storch recently observed, climate models did not include this effect.
Among other things, there is evidence that the oceans have absorbed more heat than we initially calculated. Temperatures at depths greater than 700 meters (2,300 feet) appear to have increased more than ever before. The only unfortunate thing is that our simulations failed to predict this effect.
IPCC also asserted that similar hiatuses are “common” in the instrumental record:
15-year-long hiatus periods are common in both the observed and CMIP5 historical GMST time series (see [Figure 9.8] and also Section 2.4.3, Figure 2.20; Easterling and Wehner, 2009, Liebmann et al., 2010).
As shown below, there is indeed a lengthy “hiatus” in the 20th century record, stretching almost 40 years from the 1940s until 1980. However, IPCC is surely being a bit sly in saying that 15-year-long hiatus periods were “common” in the 20th century. It is far more reasonable to say that there was a steady temperature increase from the 19th century to the 1940s, followed by a 30-40 year hiatus, then a 30-year period of increase to the end of the century.
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The suddenly-fashionable attribution of the present hiatus to unmodeled energy accumulation in the deep ocean also invites questions about the earlier hiatus, which the climate “community” conventionally attributes to aerosols. There is no independent record of historical aerosol levels, which (e.g. the prominent GISS series by Hansen’s group) have primarily been developed by climate modelers seeking to explain the long hiatus. Skeptics have long argued that aerosol histories have been used as a sort of deus ex machina to paper over excessively sensitive climate models.
Once again, IPCC invoked both “volcanic” and “aerosol” forcing as possible contributors for the present hiatus, but one feels that these efforts were somewhat half-hearted, though they did make their way to the SPM. The failure of IPCC scientists to draw attention in real time to the supposedly responsible volcanic events inevitably compromises any attempts to do so after the fact.
Thus, the sudden interest in positing energy accumulation in the deep ocean.
However, if the present hiatus is attributed to an unmodeled accumulation of energy in the deep ocean, how do we know that something similar didn’t happen during the long earlier hiatus? Could some portion of the earlier hiatus be due to deep ocean accumulation as opposed to aerosols? It’s a big door that’s being opened.
Opening the door also opens up questions about the potential length of the present hiatus. If unmodeled deep ocean processes are involved, how can we say with any certainty that the present hiatus won’t extend for 30-40 years?
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Conclusion
No credence should be given to IPCC’s last-minute attribution of the discrepancy to “natural variability”. IPCC’s ad hoc analysis purporting to support this claim does not stand up to the light of day.
Gavin Schmidt excused IPCC’s failure to squarely address the discrepancy between models and observations saying that it was “just ridiculous” that IPCC be “up to date”:
The idea that IPCC needs to be up to date on what was written last week is just ridiculous.”
But the problem not arise “last week”. While the issue has only recently become acute, it has become acute because of accumulating failure during the AR5 assessment process, including errors and misrepresentations by IPCC in the assessments sent out for external review; the almost total failure of the academic climate community to address the discrepancy; gatekeeping by fellow-traveling journal editors that suppressed criticism of the defects in the limited academic literature on the topic.
Whatever the ultimate scientific explanation for the pause and its implications for the apparent discrepancy between models and observations, policy-makers must be feeling very letdown by the failure of IPCC and its contributing academic community to adequately address an issue that is critical to them and to the public.
That academics (e.g. Fyfe et al here; von Storch here) have finally begun to touch on the problem, but only after the IPCC deadline must surely add to their frustration. Von Storch neatly summarized the problem and calmly (as he does well) set it out as an important topic of ongoing research, but any investor in the climate research process must surely wonder why this wasn’t brought up six years ago in the scoping of the AR5 report.
One cannot help but wonder whether WG1 Chair Thomas Stocker might not have served the policy community better by spending more time ensuring that the discrepancy between models and observations was properly addressed in the IPCC draft reports, perhaps even highlighting research problems while there was time in the process, than figuring out how IPCC could evade FOI requests.
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