Science Forums 2

[Turtle]

Originally Posted by Turtle

Actually it is more like 200,000 years they have ice core data for from Greenland. I hear figures as high as 600,000, but here's from the horses mouth as it were:

Originally Posted by sciamc.om

November 28, 2005 Researchers have recovered a nearly two-mile-long cylinder of ice from eastern Antarctica that contains a record of atmospheric concentrations of carbon dioxide (CO2) and methane--two potent and ubiquitous greenhouse gases--spanning the last two glacial periods. Analysis of this core shows that current atmospheric concentrations of CO2--380 parts per million (ppm)--are 27 percent higher than the highest levels found in the last 650,000 years.

http://www.sciam.com/article.cfm?art...3883414B7F0000