From the Dot Earth blog at the New York Times online:

Michael Schlesinger, a climatologist at the University of Illinois, explains why he sees the disclosed e-mails as a complete distraction from the body of evidence pointing to a human hand on the planet’s thermostat:

I would like to make the following contribution to your blog regarding the recent desperate, the-end-justifies-the-means act of stealing e-mails from the Climate Research Unit (CRU) of the University of East Anglia, U.K.

1. CRU is not the only group in the world that is tracking the change in global-average near-surface temperature. There are at least three other groups, two in the U.S. (the National Oceanic and Atmospheric Administration, NOAA; and the National Aeronautics and Space Administration, NASA), and one in Japan (Japan Meteorological Agency, JMA).

2. As presented below, the temperature record of each of these groups (available at the URLs given at the bottom of this message) shows the same features: (i) a warming of about 0.9 °C (1.6 °F) over the past 150 years and (ii) natural variability with both short and long periods.

Michael Schlesinger / University of Illinois Trends in global temperature estimated by four different research groups are very similar, both in charting pronounced warming and a lot of short-term variability. The groups are the National Oceanic and Atmospheric Administration, NASA, Britain’s Hadley Center and Climatic Research Unit (Univ. of East Anglia) and Japan’s meteorological agency.

3. In our year-2000 published analysis of these data through 1997 ( Causes of Global Temperature Changes During the 19th and 20th Centuries, Geophysical Research Letters, 27:14, 2137-2140; Natalia Andronova & Michael Schlesinger), we showed that this warming was predominantly due to people. An update of that analysis, which includes the observations since 1997, shows that the observed warming is overwhelmingly due to people.

4. Each of the four records above shows cooling in recent years. But, as is shown in these records, this recent cooling is nothing new. It was because of the likelihood of such a cooling that we concluded in our year-2000 paper referenced above that:

“… it is prudent not to expect continued year-after-year warming in the near future and, in so doing, diminish concern about global warming should global cooling instead manifest itself again.”
The absolute worst thing that humanity could do is mistake a short-term natural cooling for the absence of human-caused global warming and, in so doing, not transition as soon as economically possible from the fossil fuel age to the post-fossil fuel age.

To make this mistake would leave a legacy of global warming for our children, grandchildren and multiple generations thereafter which they likely could not reverse, and for which they would likely not forgive us.

This we must not do.

Data Sources:  NOAA,  NASA,  HADCRU (Hadley Centre/Climatic Research Unit), JMA (Japan Meteorological Agency), English pages  here and here, Japanese page translated into English.