The researchers from the Lawrence Livermore National Laboratory, the Carnegie Institution and Montpellier University II in France investigated, for the first time, the combined climate and carbon-cycle effects of large-scale deforestation in a fully interactive, three-dimensional climate-carbon model.
The study confirmed the notion that planting more trees in tropical rainforests might slow global warming worldwide. But the study also found global forests actually produce a net warming of the planet.
"Our study shows that tropical forests are very beneficial to the climate because they take up carbon and increase cloudiness, which in turn helps cool the planet" said Govindasamy Bala of the Lawrence Livermore National Laboratory and lead author of the research. But the study concludes that, by the year 2100, forests in mid- and high-latitudes will make some places up to 10 degrees Fahrenheit warmer than if the forests did not exist.
The study, to be presented Friday in San Francisco during the annual meeting of the American Geophysical Society, finds little or no climate benefit when trees are planted in temperate regions.