St. Louis Public Radio News
7:56 am
Thu March 5, 2009

Amazon drought could increase rates of climate change

St. Louis, MO –

A St. Louis researcher says global warming could happen at a quicker rate if more trees in the Amazon Rainforest die from drought.

The Missouri Botanical Garden's David Neill co-authored a study published in this week's Science Magazine. He says a 2005 drought killed thousands of trees that once absorbed carbon dioxide from fossil fuels.

Neill says losing more trees to future droughts could exacerbate the problem.

"So they contribute both by not absorbing the excess carbon dioxide and when the tree decomposes, it releases that CO2 into the air. And that could accelerate global warming."

Neill says researchers can't accurately predict when another drought could affect the rainforest.

"If these kinds of droughts happen more frequently, then large areas of forests could become reduced. And these are areas that are not disturbed by deforestation. These are natural forests that are responding to severe climatic events."

Neill says the tree mortality rate in 2005 was several times greater than in other years.