"Global warming isn't a prediction. It is happening," James Hansen wrote in a New York Times op-ed this year. Using his stature as NASA's top climate scientist, Hansen has arguably done as much as anyone to sound this alarm, forcefully and unequivocally arguing that climate change is the work of humans long before other scientists were willing to say so. A self-described "reticent Midwestern scientist," he may not look like a radical protest figure, but when it comes to the climate, Hansen is a latter-day Abbie Hoffman. After Hurricane Sandy wreaked havoc across the Eastern Seaboard in October, an American public distracted for years by the troubles of the Great Recession finally seemed to awake to the destructive potential of a changing climate -- which Hansen had been warning of for decades.
Since publishing some of the seminal studies on the effects of greenhouse gases in 1981, he has steadily ratcheted up the pressure on public officials to take his dire warnings seriously. Last year, the 71-year-old was even arrested in front of the White House after imploring President Barack Obama, via megaphone, to reject the Keystone XL pipline "for the sake of your children and grandchildren." Nor was it the first time the outspoken scientist has found himself on the wrong side of the law. He has been censored by NASA, attacked by conservatives, and denounced by other climate scientists for his advocacy. But Hansen continues to speak widely about a threat he compares to a large asteroid headed for the Earth. Just in the last few months, as Arctic sea ice shrank to its lowest level yet, he published a study finding that as much as 13 percent of the planet's surface has suffered from extreme heat in recent summers, up from less than 1 percent before 1980. We doubt Hansen is happy to see his theories confirmed.