Nature & Environment
Drying Amazon Caused Vegetation Declines and Carbon Release Over 13 Years
Catherine Griffin
First Posted: Dec 11, 2014 10:33 AM EST
Climate change may be having a major impact on Amazon vegetation. NASA satellites have shown that a 13-year decline in vegetation in the eastern and southeastern Amazon can be linked to a decade-long rainfall decline in the region.
In this case, the researchers used a new technique to measure the "greenness" of plants 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 other satellite instruments measured a .8 percent decline in greenness over the Amazon.
This decline in greenness may seem like it's small. Yet the area it covers is significant. In fact, the researchers found that the affected area included 2.1 million square miles, which is equivalent to over half the area of the continental United States.
This, unfortunately, has serious consequences for the world's load of carbon. Plants absorb carbon dioxide as part of photosynthesis and the healthier the plants are, the greener the forest.
"In other words, if greenness declines, this is an indication that less carbon will be removed from the atmosphere," said Thomas Hilker, the lead author of the new study, in a news release. "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."
The Amazon basin actually stores an estimated 120 billion tons of Earth's carbon. That's about three times more carbon than humans release into the atmosphere each year. If vegetation becomes less green, this means less carbon dioxide is taken up over time. This, in turn, means that emissions will remain in the atmosphere and that global warming may be exacerbated.
"Our observations are too short to link drying to human causes," said Hilker. "But if, as our global circulation models suggest, drying continues, our results provide evidence that this could degrade the Amazonian forest canopies, which would have cascading effects on global carbon and climate dynamics."
The findings reveal that as conditions dry out, our climate could be impacted. This, in turn, could have major implications for future climate change.
The findings are published in the journal Proceedings of the National Academy of Sciences.
For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).
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First Posted: Dec 11, 2014 10:33 AM EST
Climate change may be having a major impact on Amazon vegetation. NASA satellites have shown that a 13-year decline in vegetation in the eastern and southeastern Amazon can be linked to a decade-long rainfall decline in the region.
In this case, the researchers used a new technique to measure the "greenness" of plants 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 other satellite instruments measured a .8 percent decline in greenness over the Amazon.
This decline in greenness may seem like it's small. Yet the area it covers is significant. In fact, the researchers found that the affected area included 2.1 million square miles, which is equivalent to over half the area of the continental United States.
This, unfortunately, has serious consequences for the world's load of carbon. Plants absorb carbon dioxide as part of photosynthesis and the healthier the plants are, the greener the forest.
"In other words, if greenness declines, this is an indication that less carbon will be removed from the atmosphere," said Thomas Hilker, the lead author of the new study, in a news release. "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."
The Amazon basin actually stores an estimated 120 billion tons of Earth's carbon. That's about three times more carbon than humans release into the atmosphere each year. If vegetation becomes less green, this means less carbon dioxide is taken up over time. This, in turn, means that emissions will remain in the atmosphere and that global warming may be exacerbated.
"Our observations are too short to link drying to human causes," said Hilker. "But if, as our global circulation models suggest, drying continues, our results provide evidence that this could degrade the Amazonian forest canopies, which would have cascading effects on global carbon and climate dynamics."
The findings reveal that as conditions dry out, our climate could be impacted. This, in turn, could have major implications for future climate change.
The findings are published in the journal Proceedings of the National Academy of Sciences.
For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).
See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone