James E. Hansen of NASA, who retired in 2013 to fight global warming with activists, reflected in a window at his farm in Pennsylvania. Photo: Michael Nagle / The New York Times

By JUSTIN GILLIS
1 April 2013 (The New York Times) – James E. Hansen, the climate scientist who issued the clearest warning of the 20th century about the dangers of global warming, will retire from NASA this week, giving himself more freedom to pursue political and legal efforts to limit greenhouse gases. His departure, after a 46-year career at the space agency’s Goddard Institute for Space Studies in Manhattan, will deprive federally sponsored climate research of its best-known public figure. At the same time, retirement will allow Dr. Hansen to press his cause in court. He plans to take a more active role in lawsuits challenging the federal and state governments over their failure to limit emissions, for instance, as well as in fighting the development in Canada of a particularly dirty form of oil extracted from tar sands. “As a government employee, you can’t testify against the government,” he said in an interview. Dr. Hansen had already become an activist in recent years, taking vacation time from NASA to appear at climate protests and allowing himself to be arrested or cited a half-dozen times. But those activities, going well beyond the usual role of government scientists, had raised eyebrows at NASA headquarters in Washington. “It was becoming clear that there were people in NASA who would be much happier if the ‘sideshow’ would exit,” Dr. Hansen said in an e-mail. At 72, he said, he feels a moral obligation to step up his activism in his remaining years. “If we burn even a substantial fraction of the fossil fuels, we guarantee there’s going to be unstoppable changes” in the climate of the earth, he said. “We’re going to leave a situation for young people and future generations that they may have no way to deal with.” His departure, on Wednesday, will end a career of nearly half a century working not just for a single agency but also in a single building, on the edge of the Columbia University campus. From that perch, seven floors above the diner made famous by “Seinfeld,” Dr. Hansen battled the White House, testified dozens of times in Congress, commanded some of the world’s most powerful computers and pleaded with ordinary citizens to grasp the basics of a complex science. Around the time Dr. Hansen switched his research focus, in the 1970s, a sharp rise in global temperatures began. He labored in obscurity over the next decade, but on a blistering June day in 1988 he was called before a Congressional committee and testified that human-induced global warming had begun. Speaking to reporters afterward in his flat Midwestern accent, he uttered a sentence that would appear in news reports across the land: “It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here.” Given the natural variability of climate, it was a bold claim to make after only a decade of rising temperatures, and to this day some of his colleagues do not think he had the evidence. Yet subsequent events bore him out. Since the day he spoke, not a single month’s temperatures have fallen below the 20th-century average for that month. Half the world’s population is now too young to have lived through the last colder-than-average month, February 1985. In worldwide temperature records going back to 1880, the 19 hottest years have all occurred since his testimony. Again and again, Dr. Hansen made predictions that were ahead of the rest of the scientific community and, arguably, a bit ahead of the evidence. “Jim has a real track record of being right before you can actually prove he’s right with statistics,” said Raymond T. Pierrehumbert, a planetary scientist at the University of Chicago. […] Perhaps the biggest fight of Dr. Hansen’s career broke out in late 2005, when a young political appointee in the administration of George W. Bush began exercising control over Dr. Hansen’s statements and his access to journalists. Dr. Hansen took the fight public and the administration backed down. [more]

Climate Maverick to Retire From NASA