Humans First Altered Climate Thousands (Not Hundreds) of Years Ago
Tuesday, December 5, 2006
Humans First Altered Climate Thousands (Not Hundreds) of Years Ago
Stern Center, Great Room, 7:00 p.m.

Issue in Context
The earth’s climate naturally goes through periods of warming and cooling. Currently, the average temperature of the planet is increasing at an alarming rate. The most common conjecture of environmental scientists is that human actions are accelerating the natural warming of the planet. The amount of greenhouse gases, like carbon dioxide (CO 2 ) and methane (CH 4 ), present in the atmosphere has increased, due in part to human consumption of fossil fuels such as oil, coal and natural gas. Most scientists attribute this increase to the population growth and the industrialization of the past few hundred years in human history. However, William F. Ruddiman, a professor emeritus from the Department of Environmental Sciences at the University of Virginia suggests that significant human intervention in the natural operation in the climate system actually began 5,000 to 8,000 years ago. Even while the world population was relatively small, heavy deforestation and rice irrigation in Eurasia , compounded by additional emissions from an unusually warm ocean caused a shift in global climate. Ruddiman suggests that by the start Read more
















Issue in Context