AN INCONVENIENT TREE
April 17, 2007
Govindasamy Bala of Lawrence Livermore National Laboratory and colleagues at the Carnegie Institution's Department of Global Ecology have reached some unexpected results from modeling the effects of planting and clearing forests at latitudes high and low, says physicist Russell Seitz in the Wall Street Journal.
According to the researchers:
- Planting trees where none exist in northern areas may actually hasten global warming; northern tree plantations can trap heat -- they both absorb solar energy and shade sun reflecting snow.
- This, say the scientists, can apparently overpower the cooling effects of trees soaking up carbon dioxide and storing carbon in growing biomass.
- Take away the trees in the long-running climate model, and high latitude areas become 0.8 degrees Celsius cooler by the year 2100, when compared to a standard model of North Woods forest density.
On the other hand, says Bala, tropical reforestation efforts could slow global warming -- low latitude regions that the model left treeless until 2100 increased in average temperature by 0.7 degrees. That's a warming trend as large as the planet saw in the 20th century.
But overall, the inconvenient truth -- that ill-placed "carbon offset" reforestation schemes can backfire could give rise to a legal climate of fear, says Seitz. Will environmental lawyers chasing tree surgeons' ambulances become the next big thing in torts? The climate modeling game affords few certainties, but it seems likely that carbon-offset lawsuits will sprout from this fertile new research field.
Source: Russell Seitz, "An Inconvenient Tree," Wall Street Journal, April 14-15, 2007.
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