James Hansen From Wikipedia

James Edward Hansen (born March 29, 1941) is an American adjunct professor directing the Program on Climate Science, Awareness and Solutions[4] of the Earth Institute at Columbia University. He is best known for his research in climatology, his 1988 Congressional testimony on climate change that helped raise broad awareness of global warming, and his advocacy of action to avoid dangerous climate change.[5][6][7] In recent years he has become a climate activist to mitigate the effects of global warming, on a few occasions leading to his arrest.[8]

Hansen was born in Denison, Iowa, to James Ivan Hansen and Gladys Ray Hansen.[9] He was trained in physics and astronomy in the space science program of James Van Allen at the University of Iowa. He obtained a B.A. in Physics and Mathematics with highest distinction in 1963, an M.S. in Astronomy in 1965 and a Ph.D. in Physics in 1967, all three degrees from the University of Iowa. He participated in the NASA graduate traineeship from 1962 to 1966 and, at the same time, between 1965 and 1966, he was a visiting student at the Institute of Astrophysics at the University of Kyoto and in the Department of Astronomy at the University of Tokyo. He then began work at the Goddard Institute for Space Studies in 1967.[10]