Katrina Death Toll: 320M Trees

Hurricane Katrina killed 320 million trees in Mississippi and Louisiana, and the die-off is affecting the atmosphere as well as the landscape. Decaying trees will release about 367 million tons of carbon dioxide, equal to the amount released in a whole season of US forest fires, the LA Times reports. "In some areas, it was 100% damage," says one expert.

A new analysis of satellite photos reveals that most of the lost trees were 70 to 100 feet tall. Amidst swaths of decomposing trees are small new trees that will stay vulnerable for some time. "If we have significant fires, all of those young trees are going to be toast," says the head of the Mississippi Fish and Wildlife Foundation. (More Hurricane Katrina stories.)