Careful Where You Put That Tree

New climate modeling research from the Carnegie Institution and Lawrence Livermore National Laboratory shows that northern temperate forests may contribute to global warming, while tropical forests can help keep global temperatures cool. Forget planting trees to negate your SUV's contribution to global warming -- according to Stanford University atmospheric scientist Ken Caldeira, forests in the wrong location can actually make the Earth hotter. "Planting trees definitely sequesters carbon dioxide, which tends to lower temperatures," said Eric Adams, an ecologist in Massachusetts Institute of Technology's environmental engineering department. "It's very interesting that changing land use -- whether that means growing trees or cutting them down -- can have an effect on climate," added David Erickson, director of the Climate and Carbon Research Institute at Oak Ridge National Laboratory in Tennessee.