As the insightful Wall St. Journal editorial linked to below shows, true debate is not encouraged within acedemia when it comes to global warming. The author of the article, Dr. Richard Lindzen, is an endowed chair professor at MIT. I think that all would agree he could be described as objective. Unfortunately, when it comes to those government grants paying for study of global climate change, if you aren't supporting the thesis that global warming is occuring, and caused by human intervention, you tend to get cut off and banished...
http://www.opinionjournal.com/extra/?id=110008220