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.

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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.