A Fresh Squeeze story casts doubt on the common mantra to "plant more trees" to combat global warming.

Quoting from the article, which cites a study released by the Lawrence Livermore National Laboratory: “New tropical trees are very effective in mitigating climate change,” said atmospheric scientist Govindasamy Bala, who led the study. “New trees in mid-latitudes have near-zero climate-mitigation effect. Planting new trees in high latitudes will accelerate global warming.”

The article goes on to say that: "Although trees sequester carbon dioxide, the study showed that at latitudes greater than 50, this is cancelled out by the extra sunlight they absorb. Forest canopies capture more sunlight than the ice and snow which typically cover high latitudes. Less reflected light means more heat is held to the Earth’s surface, increasing the effects of global warming."

There is still debate about how much of an impact planting trees locally will have on balancing carbon emissions. We live at about 42 degrees latitude, so it is hardly tropical - yet. We also tend to have deciduous trees - meaning trees that shed their leaves in the fall. One of the things that does is allow for reflected light from ice and snow. We see very few "closed canopies" in the winter around here. Also, a lot of carbon in stored in the actual trunk, roots, and branches of the tree (about 1 ton over the life of the tree) - carbon that would go free otherwise. So, in the balance, I think planting more trees has to be a good thing.