Ever heard of an "Interglacial Period?" We're in one. Glaciers began receding some 18,000 years ago due to an abrupt warming trend - it's called the end of the "Ice Age." The Earth has been under siege of ice for the last 160,000 years, briefly interrupted once before during the Earmian Interglacial Period. And the warming that began 18,000 years ago wasn't a result of my SUV.