- William Ruddiman
William F. Ruddiman is a palaeoclimatologist and Professor Emeritus at the
University of Virginia . He is known principally for his "early anthropocene " hypothesis, the idea that Human-induced changes ingreenhouse gas es did not begin in the eighteenth century with advent of coal-burning factories and power plants of the industrial era, but date back to 8,000 years ago, triggered by intense farming activities of our early agrarian ancestors. It was at that time that atmospheric greenhouse gas concentrations stopped following the periodic pattern of rises and falls that had accurately characterized their past long-term behavior, a pattern which is well explained by natural variations in the Earth’s orbit known asMilankovitch cycles . In hisoverdue-glaciation hypothesis Ruddiman claims that an incipient ice age would probably have begun several thousand years ago, but the arrival of that scheduled ice age was forestalled by the activities of early farmers.The
overdue-glaciation hypothesis has been challenged on the grounds that alternative explanations are sufficient to account for the current warm anomaly without recourse to human activity, but Ruddiman challenges the methodology of his critics. (see external links)William Ruddiman is also known for his hypothesis in the 1980s that the
tectonic uplift ofTibet created the highly seasonalmonsoon al circulation that dominates Asia today.He has also proposed that the uplift of the Tibetan and
Colorado plateau s caused a reduction in atmospheric CO2 and was therefore a major causal factor in the Cenozoic Cooling trend that eventually lead to our currentIce Age [Ruddiman, W.F. and J.E. Kutzbach. 1991. Plateau Uplift and Climate Change. Scientific American 264:66-74]He has written a number of books including "".
References
External links
* [http://www.evsc.virginia.edu/faculty/people/ruddiman.shtml Home page]
* [http://www.sciam.com/article.cfm?articleID=000ED75C-D366-1212-8F3983414B7F0000 How Did Humans First Alter Global Climate?]
* [http://courses.eas.ualberta.ca/eas457/Ruddiman2003.pdf The anthropogenic greenhouse era began thousands of years ago; Climatic Change 61: 261–293, 2003]
* [http://www.realclimate.org/index.php/archives/2005/12/early-anthropocene-hyppothesis/ Debate over the Early Anthropogenic Hypothesis]
* Hazel Muir. [http://environment.newscientist.com/channel/earth/mg19926721.600-the-ice-age-that-never-was.html "The ice age that never was".] New Scientist Print Edition. 03 September 2008
Wikimedia Foundation. 2010.