Assessment of future climatic changes would be more secure if we fully understood the large or rapid climatic changes associated with the ice ages of the past 2(1/2) million years. Because records of past climates become more sparse further back in time, the most closely studied period has been the last glacial period, which commenced about 115,000 years ago, oscillated, reached its climax of 20,000 years ago and ended7,000-10,000 years ago.
展开▼
