I read about this in the paper.
Is the issue global warming, or the natural cycle of the earth?
http://www.clearlight.com/~mhieb/WVFossils/ice_ages.html
Approximately every 100,000 years Earth's climate warms up temporarily. These warm periods, called interglacial periods, appear to last approximately 15,000 to 20,000 years before regressing back to a cold ice age climate. At year 18,000 and counting our current interglacial vacation from the Ice Age is much nearer its end than its beginning.