Deforestation Causes Cooling in Northern U.S., Canada, Study Finds
ScienceDaily (Nov. 16, 2011) — The impact of deforestation on global warming varies with latitude...Paw U and his colleagues found that deforestation in the boreal region, north of 45 degrees latitude, results in a net cooling effect. While cutting down trees releases carbon into the atmosphere, it also increases an area's albedo, or reflection of sunlight. Surface temperatures in open, nonforested, high-latitude areas were cooler because these surfaces reflected the sun's rays, while nearby forested areas absorbed the sun's heat. At night, without the albedo effect, open land continued to cool faster than forests, which force warm turbulent air from aloft to the ground.
"People are debating whether afforestation is a good idea in high latitudes," said Xuhui Lee, the study's principal investigator and professor of meteorology at the Yale School of Forestry & Environmental Studies. "If you plant trees you sequester carbon, which is a benefit to the climate system. At the same time, if you plant trees you warm the landscape because trees are darker compared to other vegetation types. So they absorb solar radiation."
http://www.sciencedaily.com/releases/2011/11/111116132910.htm
