Scientists have recently discovered that deforestation in the Amazon is leading to greater changes in the Amazon’s climate and hydrological cycles than initially predicted.

• Chagnon, F.J.F. and R.L. Bras. "Contemporary Climate Change in the Amazon." Geophysical Research Letters 32(L13703). 9 July 2005 at www.agu.org/journals/gl/

Chagnon and Bras conclude that rainfall is actually increasing over deforested areas as a result of shallow cloud levels. Deforestation thus becomes another determining factor of the region's hydrologic cycle.

Implications: Scientists have already concluded that deforestation releases significant levels of greenhouse gases, which are stored in the forest's carbon sinks. According to many scientists, increased levels of greenhouse gases are altering global precipitation levels and variance. This study implies that deforestation by itself can also dramatically change hydrological cycles, compounding climate change effects. Given its size and role in distributing freshwater through the ecosystem, the Amazon hydrological cycle is key to global climate patterns. The study's findings suggest that the shifting patterns of rainfall and shallow clouds could have dramatic implications for the global climate.