Hansen On McIntyre

James Hansen is the man who, arguably, sounded the alarm on AGW way back in the 1980s. This makes him Public Enemy #2 in the Climate Change Denialist community, Al Gore currently holding the #1 spot. He has been the target of much blogosphere venom after S. McIntyre uncovered a minor error in the GISSTEMP temperatures for the U.S.A., the care and upkeep of GISSTEMP being one of Hansen's responsibilities. Here is his response to the latest controversy. My favorite bit is the conclusion:

The flaw did have a noticeable effect on mean U.S. temperature anomalies, as much as
0.15°C, as shown in Figure 1 below (for years 2001 and later, and 5 year mean for 1999 and
later). The effect on global temperature (Figure 2) was of order one-thousandth of a degree, so
the corrected and uncorrected curves are indistinguishable.

Contrary to some of the statements flying around the Internet, there is no effect on the
rankings of global temperature. Also our prior analysis had 1934 as the warmest year in the U.S.
(see the 2001 paper above), and it continues to be the warmest year, both before and after the
correction to post 2000 temperatures. However, as we note in that paper, the 1934 and 1998
temperature are practically the same, the difference being much smaller than the uncertainty.

Somehow the flaw in 2001-2007 U.S. data was advertised on the Internet and for two
days I have been besieged by rants that I have wronged the President, that I must “step down”, or
that I must “vanish”. Hmm, I am not very good at magic tricks.

Other responses to the GISSTEMP glitch can be found here, here, and here, where McIntyre tries to cool the rhetoric and again invokes some of the weird, rural good/urban evil (Red State vs. Blue State?) political symbolism that has been creeping into Denialist rhetoric over the past several months.