I did so knowingly, aware that people who deny the reality of climate change had singled him out for vilification, largely because of allegations of misbehavior revealed by the "climate-gate" hacked emails.
Two things have happened since then.
First, China has gone ahead with its cleaner-coal projects, while many on the US side have been delayed, scaled down, or zeroed-out because the federal support for the research is already being pared back. Great.
Second, Michael Mann has been cleared, of all charges of misconduct, yet again.
You can read about it in a Bloomberg report on a National Science Foundation investigation of Mann. If you want, you can get the full NSF findings in PDF form. The NSF goes through the assorted "climate-gate" charges and concludes, laconically if with sub-optimal grammar:
>>Finding no research misconduct or other matter raised by the various regulations and laws discussed above, this case is closed.<<
Mann had previously been cleared in an investigation by Pennsylvania State, and in a related study by NOAA.
I go out of my way to mention this for several reasons. First, because a serious scientist has been vilified, without basis, mainly because his work bears on current politics. "Oh, never mind" clearance from charges rarely gets as much publicity as the original charges themselves. The fact that every scientific body examining Mann's behavior has exonerated him deserves publicity and emphasis. For the record, I have interviewed Mann but don't have any connection to him beyond that.
Also, after my article came out I was inundated with mail by people who said, How can you quote this fraud? (Almost as much mail as I got from people on the left, saying, How can you say we're going to keep using coal?) Well, Mann is not a fraud. As a human being and as a scientist he deserves to have that stated again and again.
Finally, I raise this episode as a guide. If you hear people talking in environmental debates about "climate-gate" and "Mann's misconduct," recognize that what you're hearing is just like "Obama was born in Kenya." These people are either passively uninformed or knowingly beyond the reach of fact. And if they can't be convinced by the National Science Foundation, NOAA, Penn State, and various European counterparts, then they are in the realm of being anti-science.
(Updates: also see this critique by Michael Ham of "balanced" he-said/she-said coverage of the issue by the WaPo. Also, consider for a moment the incredible, "can this really be 2011?" implications of the headline on Ron Brownstein's very good article on our site: "Evolution, Climate Change Could Divide the Republican Party." A major, "modern" political movement is being torn apart by the theory of evolution??? Also: for another comparison of "climate-gate" thinking with birtherism, see Climate Crocks.)
One of Mann's principal critics has been Sen. James Inhofe of Oklahoma. It would be overkill to do more than mention the inelegance of Inhofe's role as a vengeful judge of others' careful observance of rules.