Michael E. Mann (born 1965) is an American climatologist and geophysicist, currently director of the Earth System Science Center at Pennsylvania State University, who has contributed to the scientific understanding of historic climate change based on the temperature record of the past thousand years. He has pioneered techniques to find patterns in past climate change, and to isolate climate signals from "noisy data".As lead author of a paper produced in 1998 with co-authors Raymond S.