James Hansen: Why I Must Speak Out about Climate Change

TED has just made available a recent talk (filmed in February 2012) by noted climatologist, Dr. James Hansen. An Iowa native, Hansen studied mathematics, physics, and astronomy at the University of Iowa, where Dr. James Van Allen headed up the Department of Physics and Astronomy. Hansen's 1967 doctoral dissertation was entitled, The Atmosphere of Venus: A Dust Insulation Model, and he has since had a long scientific career investigating the basis of global climate change and advocating for the reduction of greenhouse gas emissions into the Earth's atmosphere.