Paleoclimatologists seem to have been at this debate for awhile:


In Ancient Fossils, Seeds of a New Debate on Warming :

http://www.nytimes.com/2006/11/07/sc...SlpKXwMAB7v2DQ


Here is the blog in which I found this article, Lounge of the Lab Lemming

http://lablemminglounge.blogspot.com...imatology.html