Dr. David J. Helfand is Chair of the Department of Astronomy at Columbia University. Dr. Helfand’s science course, part of Columbia’s famed Core Curriculum, is taught to all Columbia’s first year students. He received the University’s 2001 Presidential Teaching Award and the 2002 Great Teacher Award from the Society of Columbia Graduates. Dr. Helfand spent … Continue reading "Town Hall: David Helfand – “Global Climate Change: What We Know and What We Don’t Know”"