16. This diagram sows the highly variable nature of earth temperature over 16,000 years, with detail for the last 2000 years. Depending on the period of the earth’s history that is chosen, the climate will either be warming or cooling. Choosing whether earth is warming or cooling is simply a matter of picking end points.
Davis, John C., and Geoffrey Bohling, 2001, The Search for Patterns in Ice-Core Temperature Curves: in Gerhard, Lee C., William E. Harrison, and Bernold M. Hanson, eds.,2001, Geological Perspectives of Global Climate Change: American Association of Petroleum Geologists Studies in Geology #47, Tulsa, OK, p. 213-230.