Selfish trees

The world is getting warmer.
The only question that remains is how much of that warmth is caused by human beings, their machines and their flatulent domesticated cows?
One silent ally in this battle to keep their earth cool is trees -- sucking in carbon dioxide and giving us oxygen.
Well, there's one in every crowd, and it turns out that some trees in northern latitudes are actually sucking in heat that would normally be reflected back into space.
Research reported in this week's online edition of Proceedings of the National Academy of Sciences says that tropical forests do their jobs at sucking up carbon and helping make clouds that help us keep cool.
It's the woods up north, the ones we go through to get to grandma's house at Christmas time, that are adding to our problem by absorbing solar energy that would otherwise be reflected back out into space.
If you can't trust the trees, who can you trust?
For more info on the treacherous trees go to http://www.msnbc.msn.com/id/18027048/