October 30, 2012
Permafrost Study Shows That Not All Soils Are Alike
Brett Smith for redOrbit.com - Your Universe Online
As global warming extends its balmy fingers further into the Arctic regions, defrosting permafrost could release up to 44 billion tons of nitrogen and 850 tons of carbon into the atmosphere, according to a new study from the U.S. Geological Survey (USGS).
The doubling of atmospheric carbon that would result from such an unprecedented thaw figures to impact ecosystems, the atmosphere, the Earth´s lakes and rivers, the researchers said in their report that was published in the journal Geophysical Research Letters.
"This study quantifies the impact on Earth's two most important chemical cycles, carbon and nitrogen, from thawing of permafrost under future climate warming scenarios," said USGS Director Marcia McNutt. "While the permafrost of the polar latitudes may seem distant and disconnected from the daily activities of most of us, its potential to alter the planet´s habitability when destabilized is very real."
To understand how a thawing of permafrost could unfold, the scientists examined Arctic soils known as gelisols and found a wide range of gelisol composition. Some peaty soils with a high amount of decaying matter would burn very easily if they are not submerged and that combustion would release high amounts of nitrogen into the atmosphere and ecosystem upon defrosting.
Other gelisols were found to be nutrient rich and scientists said these materials would impart nitrogen directly into the ecosystem.
"What this paper was trying to say is that, 'Look, not all of these soils are alike, and when they thaw, their vulnerabilities to different kinds of climate forcings will be different," lead USGS Research Soil Scientist Jennifer Harden told the Associated Press.
According to the researchers, all gelisols would impart greenhouse gases like carbon and some methane into the atmosphere if an Arctic thaw were to allow their organic material to decompose.
"The scientific community researching this phenomena has made these international data available for the upcoming Intergovernmental Panel on Climate Change,” said Harden in a statement. “As permafrost receives more attention, we are sharing our data and our insights to guide those models as they portray how the land, atmosphere, and ocean interact."
Harden added that an increase in the amount of nitrogen by 44 billion tons in the ecosystem would also have a massive nutrient effect on the world´s plants and this aspect of the permafrost begs for further study.
"We were able to say, 'Is this a small number we can ignore or is that a big enough number that we need to do a lot more science on it?'" she said. "The latter is clear. We need to do a lot more science on it."
The new USGS study was conducted in coordination with the Vulnerability of Permafrost Carbon Research Coordination Network (RCN), which is a National Science Foundation-funded project.
“The main objectives of this RCN are to synthesize and link existing research about permafrost carbon and climate in a format that can be assimilated by biospheric and climate models, and that will contribute to future assessments of the Intergovernmental Panel on Climate Change (IPCC),” according to an official statement on the network´s website.