Downed Trees Called Warming Factor

As if Hurricane Katrina’s effect on life and property along the Gulf Coast were not bad enough, researchers at Tulane University and the University of New Hampshire now say the storm may contribute to global warming.

The researchers point to the estimated 320 million large trees that were killed or severely damaged by Katrina.

Jeffrey Chambers, an assistant professor of ecology and evolutionary biology at Tulane, says young, healthy forests are important in the battle against warming because they remove carbon — in the form of carbon dioxide, a greenhouse gas — from the atmosphere by photosynthesis.

Dead trees and downed wood, on the other hand, decompose and release carbon into the atmosphere.

“The carbon that will be released as these trees decompose is enough to cancel out an entire year’s worth of net gain by all U.S. forests. And this is only from a single storm,’’ Chambers, the lead author of an article detailing the team’s findings, said.

The article, “Hurricane Katrina’s Carbon Footprint on Gulf Coast Forests,’’ is published in the most recent issue of the journal Science.

As the Earth’s climate warms, evidence is mounting that hurricanes, tornados and frontal systems will gain in energy, producing more violent storms and stronger winds, Chambers said.