Woodsman, Woodsman, Spare That Tree...

... if it happens to be in a tropical rainforest. Otherwise, ummm, maybe nevermind.

The Economist, in this subscription required story reports that a new model shows that trees aren't unequivocally beneficial as a prophylactic against global warming. Dr. Govindasamy Bala and colleagues, of the Lawrence Livermore National Laboratory have reported results of a new model which purportedly shows a double-edged role for trees in global climate.

On the positive side, they absorb CO2 and tuck it away in their roots, branches, and trunks for a few decades or centuries. On the negative side, they tend to decrease the planetary albedo, especially in the far North, where they absorb more radiation than the snow lying mostly under them. The model apparently shows a net negative effect for trees in the far North and indicates that planting trees in New York City is not so useful as planting them in the tropics.

There are a lot of questions I would like to see answered before I take this very seriously. In particular, one key role of forests is to produce and protect topsoil, which in Northern climes is a much bigger carbon sink than the trees themselves. Preserving tropical forests is a very good idea for lots of reasons, however, so it would be worthwhile to suggest that some of the "tree planting" environmental protection money that Gore and others pay go to that cause.