Did Humans Begin Causing Major Climate Change 8,000 Years Ago?
How Did Humans First Alter Global Climate?
Scientific American, March 2005 issue
A bold new hypothesis suggests that our ancestors' farming practices kicked off global warming thousands of years before we started burning coal and driving cars By William F. Ruddiman
Read the rest in the March 2005 issue of Scientific American at your library or newsstand.
My guess is that the author is mistaken, but he is no dope. My reason for this opinion is that 8,000 years ago, there just were not enough humans to make a significant difference in climate.