don’t plant trees!

A new study, however, published in Proceedings of the National Academy of Sciences reports that forests’ other climatic effects can cancel out their carbon cleaning advantage in some parts of the world.

Using a three-dimensional climate model, the research team mimicked full global deforestation and also studied the effects of clear-cutting in different regions of latitude, such as the tropics and boreal zones.

Apparently, these natural carbon sinks only do their job effectively in tropical regions; in other areas, they have either no impact or actually contribute to warming the planet. In fact, according to this model, by the year 2100, if all the forests were cut and left to rot, the annual global mean temperature would decrease by more than 0.5 degree Fahrenheit.

“I’m not sure the slight amount of cooling is necessarily significant, but that removing all the forest produced little change” on temperature is, says study co-author Ken Caldeira, an ecologist at the Carnegie Institution of Washington’s Department of Global Ecology in Stanford, Calif.

“I think what’s interesting is this global cancellation was a product of very different responses at different latitudes.”

Scientific American, 10 Apr 2007

see also – having it both ways