Tropical Deforestation Alters Climate, Puts Agriculture at Risk.

Tropical Deforestation Alters Climate, Puts Agriculture at Risk.

Tropical Deforestation Alters Climate, Puts Agriculture at Risk.

Tower, ground-based and satellite observations indicate that tropical deforestation results in warmer, drier conditions at the local scale. Understanding the regional or global impacts of deforestation on climate and ultimately, on agriculture, requires models. General circulation models show that completely deforesting the tropics could result in global warming equivalent to warming experienced since 1850, with more warming and considerable drying in the tropics. More realistic scenarios yield less warming and less drying and suggest critical thresholds beyond which rainfall is substantially reduced. In models that capture topography and vegetation-based discontinuities, small clearings can actually enhance rainfall, but only up to a point.Tropical agricultural output is at risk from a deforestation-induced increase in mean temperature, associated heat extremes, and a decline in mean rainfall or rainfall frequency. Through teleconnections, negative impacts on agriculture could extend well beyond the tropics.

In December 2014 Professor Deborah Lawrence and Karen Vandecar (PhD 2010) published a review in Nature Climate Change  analyzing the impact of tropical deforestation on local, regional and global climate. They assessed over 150 studies that focused on modeling, field and satellite observations. Ultimately, Lawrence and Vandecar synthesized disparate results to yield  a coherent understanding of changes in temperature and rainfall as a function of the spatial scale of deforestation, the timing and total extent of deforestation, and the land use for which tropical forests are cleared.

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