When Tundra Turns Boreal

NASA researchers have found that Alaska's North Slope tundra ecosystem is transforming into something that more closely resembles the boreal forests of the south.

During Arctic summer, warmer temperatures thaw the uppermost layers of permafrost, allowing microbes to break down previously frozen organic matter.This process releases carbon dioxide into the atmosphere. Plant growth also increases during this period - and plants remove carbon dioxide from the atmosphere through photosynthesis. But as temperatures increase, the amount of time carbon is stored in the Arctic soil decreases. 

"The balance between these two dynamics will determine whether Arctic ecosystems will ultimately remove or add atmospheric carbon dioxide in the future climate. Our study finds that the latter is more likely," said lead author and former JPL postdoctoral researcher Sujong Jeong of Seoul National University. "We anticipate that residence time of Arctic carbon will lead to faster and more pronounced seasonal and long-term changes in global atmospheric carbon dioxide."