NASA says Amazonian drought could accelerate global climate change

Washington, D.C., United States (AHN) – A NASA-funded study says droughts in the Amazon rainforest have reduced its “greenness,” and is seen as an effect of negative climate change in the region. With continued deterioration, experts say the region could transition from a rainforest to a woody savanna or even simple grassland.

“Last year was the driest year on record based on 109 years of Rio Negro water level data at the Manaus harbor,” said co-author Marcos Costa from the Federal University in Vicosa, Brazil. “For comparison, the lowest level during the so-called once-in-a-century drought in 2005 was only eighth lowest.”

Experts from an international research team examined decades of data gathered from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) and Tropical Rainfall Measuring Mission (TRMM). The team fears transition to a savanna because of the carbon that will be released into the atmosphere as dying trees rot in the formerly verdant rainforest.

“The greenness levels of Amazonian vegetation – a measure of its health – decreased dramatically over an area more than three and one-half times the size of Texas,” co-lead author Liang Xu from Boston University explained. “It did not recover to normal levels, even after the drought ended in late October 2010.”

“The MODIS vegetation greenness data suggest a more widespread, severe and long-lasting impact to Amazonian vegetation than what can be inferred based solely on rainfall data,” co-lead author from Atmospheric and Environmental Research Inc. Arindam Samanta added.

According to NASA, the study can be found in an upcoming edition of ‘Geophysical Research Letters,’ a journal of the American Geophysical Union.

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