The sudden death in July of Stanford University climatologist Stephen Schneider silenced an influential voice in the global discussion on climate change, Schneider's fellow scientists agreed Sunday.
In a combined "scientific symposium" and memorial event, more than 400 of Schneider's colleagues and friends -- including White House Science and Technology Policy Director John Holdren -- recalled Schneider's gift for explaining complex scientific findings in terms the public could understand.
They also speculated on why, in the face of "overwhelming" scientific evidence accumulated since the 1930s on human-caused global warming, climate change contrarians have gained political traction in Washington.
The 65-year-old Schneider died July 19 after suffering a pulmonary embolism on a flight from Sweden, where he was attending a science meeting, to London.
A biology professor at Stanford, he was a lead scientist on the United Nations' Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize with former Vice President Al Gore.
Holdren said Schneider was "tireless in explaining to the less-informed and skeptical that our understanding of how global climate works rests not on speculation or untested computer models but on a veritable mountain of evidence ... and incontrovertible data.
"There is equally unambiguous evidence tying a large part of the (greenhouse gas) increases to human activity," he said.
Asserting that the scientific "core conclusions" on climate change are all but irrefutable, Holdren said, "It seems the height of irresponsibility for policymakers who assert the science is wrong to bet the public's welfare against" overwhelming evidence.
Schneider's many publications included the 2009 book, "Science as a Contact Sport," laying out his perspective on global-warming science and politics; as well as "The Patient from Hell," a 2007 account of how he obtained "the best of modern medicine" after being diagnosed in 2001 with a rare form of non-Hodgkin's lymphoma.
Holdren lauded the "unfailing courtesy, respect and patience with which (Schneider) treated everyone, even climate change contrarians, some of whose shenanigans have caused others of us to lose our patience.
"Although he was the best there is at demolishing the positions of the deniers and the delayers, he always did it politely," Holdren said.
Scientifically acknowledged truths about climate change have become "the victims of political ideology" in the hands of individuals, including some scientists, who have exploited some of the uncertainties surrounding global warming, said University of California, San Diego, science historian Naomi Oreskes.
"My recent work is aimed at explaining how we came to this place of rejecting scientific evidence, of having opinions about the natural world aligning to political party," said Oreskes, author of "Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming," published this year.
A key player in sowing public doubt has been the Virginia-based George C. Marshall Institute, founded by three scientists in 1984 to defend President Ronald Reagan's Strategic Defense Initiative (dubbed Star Wars) against a widespread scientific boycott, Oreskes said.
The group or its founders since have worked to cast doubt on the harms of tobacco, the reality of acid rain and the severity of the ozone hole as well as human causes of global warming, she said.
Stanford social scientist and pollster Jon Krosnick disputed oft-repeated conclusions that the Democratic rout in November's elections was a rebuke to climate science.
A careful reading of public opinion polls suggests "a large majority of Americans agree with natural scientists on the basics, and has for a number of years," Krosnick said.
Stanford President John Hennessy mourned Schneider "first and foremost as a scientist," who was also a "great collaborator and great colleague."
As the university has moved to build "multidisciplinary teaching and research efforts" on a variety of world problems, Schneider's depth of knowledge and commitment "really helped convince a lot of people about the critical challenge we face on our planet," Hennessy said.