"The UN's Intergovernmental Panel on Climate Change (IPCC) predicted in 2007 that average global temperatures would go up before 2100 by 1.1 C to 6.4 C (2.0 F to 11.5 F), depending on efforts to curb the gases that drive global warming. Any increase of more than 2.0 C, the panel said, would unleash a maelstrom of human misery, including drought, famine, disease and forced migration."
Read more at: http://phys.org/news/2009-04-forests-flip-source-co2.html