NASA Study Shows 13-year Record of Drying Amazon Caused Vegetation Declines
http://www.nasa.gov/content/goddard/13-year-record-of-drying-amazon-caused-vegetation-declines/[font face=Serif][font size=5]NASA Study Shows 13-year Record of Drying Amazon Caused Vegetation Declines[/font]
December 10, 2014
[font size=4]A 13-year decline in vegetation in the eastern and southeastern Amazon has been linked to a decade-long rainfall decline in the region, a new NASA-funded study finds.[/font]
[font size=3]With global climate models projecting further drying over the Amazon in the future, the potential loss of vegetation and the associated loss of carbon storage may speed up global climate change.
The study was based on a new way to measure the greenness of plants and trees using satellites. While one NASA satellite measured up to 25 percent decline in rainfall across two thirds of the Amazon from 2000 to 2012, a set of different satellite instruments observed a 0.8 percent decline in greenness over the Amazon. The study was published on Nov. 11 in Proceedings of the National Academy of Sciences.
While the decline of green vegetation was small, the area affected was not: 2.1 million square miles (5.4 million square kilometers), equivalent to over half the area of the continental United States. The Amazon's tropical forests are one of the largest sinks for atmospheric carbon dioxide on the planet.
"In other words, if greenness declines, this is an indication that less carbon will be removed from the atmosphere. The carbon storage of the Amazon basin is huge, and losing the ability to take up as much carbon could have global implications for climate change," said lead author Thomas Hilker, remote sensing specialist at Oregon State University in Corvallis, Oregon.
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http://www.pnas.org/content/111/45/16041.abstract
http://dx.doi.org/10.1073/pnas.1404870111