There has been considerable recent discussion of the fact that observations have been running cooler than models – see, for example, Lucia’s discussion of IPCC AR5 SOD Figure 9.8 (see here). However, Michael Mann at AGU took an entirely different line. Mann asserted that observations were running as hot or hotter than models. Mann’s assertion […]
No single topic seems to arouse as much blog animosity as any discussion of Hansen’s projections. Although NASA employees are not permitted to do private work for their bosses off-hours (a currying favor prohibition, I suppose) – for example, secretaries are not supposed to do typing, over at realclimate, Gavin Schmidt, in his “private time”, […]
Hansen et al 1988 reported that they expected extra warming in the SE United States, a theme that was mentioned in his testimony in Washington in summer 1987. Hansen et al 1988 stated: there is a tendency in the model for greater than average warming in the southeastern and central U.S. and relatively cooler or […]
During our discussions of the differences between Hansen Scenarios A and B – during which the role of CFCs in Scenario A gradually became clearer – the absence of a graph clearly showing the allocation of radiative forcing between GHGs stood out rather starkly to me. When Gavin Schmidt re-visited the topic in May 2007, […]
This is a somewhat restated version of an earlier post seeking to understand the differences between Hansen Scenarios A and B. Rather than trying to clarify matters here, Gavin Schmidt posted over at Tim Lambert’s. In this morning’s post, I correctly identified that the difference between Scenarios A and B for periods up to the […]
I’m making some changes to this post in light of comments from Gavin Schmift.
Update (Jul 28, 2008): On Jan 18, 2008, two days after this article was posted, RSS issued a revised version of their data set. The graphics below are based on RSS versions as of Jan 16, 2008, the date of this article, and, contrary to some allegations on the internet, I did not “erroneously” use […]
Another interesting post from Willis: James Hansen of NASA has a strong defense of model reliability here In this paper, he argues that the model predictions which have been made were in fact skillful (although he doesn’t use that word.) In support of this, he shows the following figure: (Original caption)Fig. 1: Climate model calculations […]
Climate Audit 