Environmental researcher William Ruddiman will present a free public talk called “We Altered Global Climate Long Before You Thought We Did.” Light refreshments are served prior to the talk, which is part of the Montana Institute on Ecosystems’ Distinguished Visiting Lecturer Series. Ruddiman has explored many aspects of the field of paleoclimate: the study of ancient climates). Ruddiman’s most recent research has concentrated on how farmers have impacted climate during the last several thousand years by clearing land, raising livestock and irrigating rice paddies, all of which put increasing amounts of greenhouse gases into the atmosphere. Ruddiman is a professor emeritus of the University of Virginia, and an elected fellow of the Geological Society of America and the American Geophysical Union. He is author of Earth’s Climate: Past and Future and has been featured in films on the Discovery Science Channel, NOVA and BBC.