Climate scientist James Hansen: 'I don't think I'm an alarmist'

James Hansen has crossed the classic divide between research and activism. In an interview with Yale Environment 360, he responds to critics and explains why he believes the reality of climate change requires him to speak out

Climate scientist James Hansen has been a prominent figure in the global climate conversation for more than 40 years. His 1988 congressional testimony on climate change helped introduce the problem of rising greenhouse gas emissions to the American public, and he has led study after study examining exactly how our world will change as a result of global warming.
Eight years ago, however, Hansen made the rare decision to begin engaging in climate activism, and he has since protested mountaintop removal in West Virginia and gotten arrested outside the White House in a rally against the Keystone XL pipeline.

His actions have earned him both praise and criticism from the media and scientific community. Recent scientific endeavors of his - including a study last month that was publicized prior to being peer-reviewed - have also generated controversy.