17. Although the earth appears to be warming now, recently past
were warmer than the present one. See slide 18 for example.
Bluemle, John P., Joseph Sable, and Wibjorn Karlen, 2001, Rate and
Magnitude of Past Global Climate Changes: 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. 193-212.