"The dramatic temperature increases that thawed the last ice age followed spikes in carbon dioxide levels in the air, a new study finds. Researchers say that further strengthens the scientific case explaining current man-made global warming."
"In the new study, scientists show the atmospheric concentration of that heat-trapping greenhouse gas jumped more than 40 percent. Then global temperatures went up about 6 degrees Fahrenheit.
What is remarkable is that when the two are plotted they rise, plateau and rise again in a striking similar way with a slight lag. The warming over 6,000 years follows the greenhouse gas increase, just as scientific theory has long held."
Seth Borenstein reports for the Associated Press April 4, 2012.