NEW HAVEN, CONN.—It’s been exactly a year since “Climategate” broke, putting Penn State University researcher Michael Mann and climate scientists on both sides of the Atlantic in the hot seat after hackers released private e-mails from the Climatic Research Unit at the U.K.’s University of East Anglia.

While Mann and colleagues now face new political and legal challenges from a Republican-dominated U.S. House of Representatives and an investigation by Virginia’s attorney general, the researcher is unbowed in his personal efforts to combat climate skeptics and draw attention to the overwhelming evidence supporting human-caused climate change.

“We have to make it clear that the ice sheets are not Republican or Democrat. They don’t have a political agenda as they disappear,” warned a pugnacious Mann, in a man-the-torpedoes appearance before a crowd of journalists attending ScienceWriters2010 and the annual New Horizons in Science briefings, held this year at Yale University.

“I have no doubt we are in for a period over the next months where climate science is subject to a politically motivated inquisition,” he said, “that we haven’t seen in this country since the 1950s.”

In Mann’s case, he and others face the prospect of being called to testify at Republican-led House hearings on their climate research, as well as the Virginia attorney general’s attempt to get e-mail correspondence written while he was at the University of Virginia. Scientists, of course, are not exempt from Freedom of Information and Congressional subpoena requirements—nor should they be. But these hearings may well present an opportunity for Mann and others to reaffirm the integrity of climate science.

“They can threaten whatever they want,” Mann told MSNBC science editor Alan Boyle after his talk. “I’m quite confident to fight those sorts of witch-hunt attempts.” Boyle observed that “although Mann didn’t exactly say ‘Bring it on,” he did note that ‘those on the other side of the aisle will see this as an opportunity…. We should look at this as an opportunity for offense,’ he said.”

Mann has undoubtedly grown a tougher skin following last year’s brouhaha over leaked e-mails about climate data that critics used to fuel the so-called “Climategate” scandal. The onslaught of attention raised public uncertainty about climate change and the need for tough international controls, just as world leaders were about to gather for the UN conference in Copenhagen in what turned out to be a largely failed attempt to prompt new international action.

In his talk, Mann condemned the timing of the e-mail release as an “intentional effort to distort” the science and “manufacture uncertainty and doubt.” He compared “the well-funded campaign to distract the public” to early industry efforts to undermine scientific evidence showing that smoking caused lung cancer and other health effects.

“The fringe media pounced on this,” said Mann. “This distracted the public at a critical juncture.” But he held the mainstream media liable as well. “I’d like to say the mainstream media recognized it for what it was (but) many journalists were fairly uncritical in their reporting of the controversy.” Going forward, he said, climate scientists are “reliant on the willingness of the mainstream media to serve as critical and independent arbiters.” Scientists won’t be successful in explaining their findings, he said, “unless the media is serving its role.”

Against a photo backdrop of his young daughter in front of a polar bear swimming in the waters of a local zoo, Mann ended with an emotional appeal: “I can’t imagine having to tell her when she’s grown up that the polar bear became extinct because of loss of arctic ice (and) we didn’t act soon enough to combat a problem that we knew was real but that we couldn’t convince the public of.”

He described the climate scientist’s role as not only doing research but calling out disinformation, as he has done in public statements and testimony, and as a founder of the scientists’ blog RealClimate. He also took on The Washington Post editorial decision last December to let former GOP vice presidential candidate Sarah Palin write what he called “an entirely bogus op-ed” condemning human-caused climate change that “presented a very distorted view to the public” (Palin charged that “so-called climate change experts” were part of a “highly politicized scientific circle”). He got the paper to publish his own op-ed rebuttal nine days later.

In his scientific presentation at Yale, Mann reviewed the evidence bolstering human-caused climate change, including his own work on the “hockey stick” graph reconstructing global climate temperatures over the ages (it resembles a hockey stick with a long steady handle and a curved upswing in modern times reflecting human-caused temperature rises). Several lines of science have produced so much evidence of the human role in accelerating climate change that Mann joked that there’s enough now for “a hockey league.” He noted that global temperature was now “running the highest ever.”

There are, of course, still “legitimate uncertainties” in the science, including understanding and modeling the dynamics of other meteorological phenomena, such as El Nino and La Nina, and their impact on regional climate change, said Mann. But, he added, the “public discourse is still so far from the scientific discourse.” Some time ago, “I gave up on the notion that facts alone would carry the day,” he said. “We live in a world where you are now entitled to your own facts.”

A Science News blog by science writer Alexandra Witze offered a personal reflection on the frustrated Penn State scientist: “I’ve seen Mann in this frame of mind before; several years ago he testified in front of some of his staunchest critics at a National Academy of Sciences panel set up to review the hockey stick work. The jaw I saw clenched back then seemed not to have loosened, even when the audience was a group of friendly journalists rather than the aggressive panel questioners. (The final NAS report reaffirmed the basic science underlying the hockey stick reconstruction.)”

Ironically, Mann said that the partisan divide increased following former Vice President Al Gore’s embrace of climate change, his “Inconvenient Truth” documentary and his Nobel Prize, which increased public awareness but also “polarized the issue politically,” given Gore’s Democratic credentials and close run for the presidency against George W. Bush.

In contrast to Mann’s mix of science and politics, National Academy of Sciences president Ralph J. Cicerone’s talk to science writers here was a careful review of the science and impact of climate change in the low-key, even-handed style for which he is known. As one of the early leaders in climate research, Cicerone worked in the 1980s at the government’s National Center for Atmospheric Research in Boulder with the late, great science communicator Dr. Stephen Schneider, who died unexpectedly last July.

Asked in an interview about what he thought of media coverage over the past year, Cicerone was characteristically circumspect: “I don’t have any fault with the media coverage. The media was covering the news. That was no surprise.”

Looking ahead, given the politicized environment in Washington, Cicerone said he was counting on science media coverage of new evidence documenting the impact of climate change around the globe “to help clear the air.” He noted that ongoing measurements of surface temperature, ice, and sea level provide “consistent signals that the planet is warming…. We need to keep watching the data. We’re confronted with a long-term issue that isn’t going to go away. We need to keep the focus on this issue.”

Ed. Note: Russell is president of the Council for the Advancement of Science Writing, which organizes the New Horizons in Science briefings and a member of the National Academies’ Communication Awards judging committee.

Cristine Russell is a CJR contributing editor and the president of the Council for the Advancement of Science Writing and a senior fellow at Harvard's Belfer Center for Science and International Affairs. She is a former Shorenstein Center fellow and Washington Post reporter.