The Anthropogenic Era Began Thousands of Years Ago

William F. Ruddiman
Department of Environmental Sciences, University of Virginia


Professor Ruddiman will discuss the onset of anthropogenic trends in greenhouse gases (GHG). He will provide evidence that the anthropogenic CH4 signal took over from natural trends at 5000 BP (rice irrigation) and that the anthropogenic CO2 signal took over from natural trends at 8000 BP (forest clearance). These early GHG signals stopped a glaciation that should have developed by 5K-4KBP


Bill Ruddiman is a marine geologist. He received his PhD from Columbia University, and is currently a professor in the Department of Environmental Sciences at the University of Virginia. He was the Chair of this department from 1993 -1996. Prior to this, he was a senior research scientist at the Lamont-Doherty Observatory in New York, a program associate with the National Science Foundation, and a Senior Scientist/Oceanographer with the U.S. Naval Oceanographic Office in Maryland.