Depopulation and Greenhouse Gas Drops, Professor Bill Ruddiman, UVA
The Thursday talk – first of two in Professor Bill Ruddiman’s visit to Yale – is called “Depopulation and greenhouse-gas drops”. It summarizes evidence for drops in CO2 and CH4 concentrations during historical time prior to the industrial era. Then it reviews two possible causes: natural climate changes, and depopulation events that reduced anthropogenic gas emissions. For the largest CO2 decrease (between 1525-1610), natural causes were not the major factor. The main cause was the huge depopulation of the Americas because of disease brought in by Europeans. Previously deforested regions used for agriculture reverted to forest and absorbed CO2.
Bill Ruddiman is a paleoclimatologist best known for his work demonstrating the global meteorological impact of the rise of the Tibetan Plateau, and his controversial theory that the anthropocene began thousands of years ago with the development of agriculture. Professor Ruddiman’s talk is the latest in an on-going series that represents a collaboration between Yale’s History, Anthropology and Humanities Departments and the Yale Climate and Energy Institute.