It's no secret that our warming climate is causing ice everywhere to melt, but now new research shows that this thaw may release a massive storehouse of carbon in long-frozen Arctic soils. This could potentially have a catastrophic effect on climate change, which is already wreaking havoc on the environment and wildlife around the world.
While climatologists have been closely monitoring carbon dioxide (CO2) levels in the atmosphere, it seems they should be focusing just as much on what's under their feet as what's in the air. The Arctic contains a massive amount of carbon locked within its frozen soil - the remnants of plants and animals that died more than 20,000 years ago.
Until recently, this permafrost had not been a threat to our climate. That's because it was frozen year-round, and didn't undergo decomposition by bacteria the way organic material does in a warmer climate. Just like food in a home freezer, it had been safe from the bacteria that would otherwise cause it to decay and be converted to CO2.
"However, if you allow your food to defrost, eventually bacteria will eat away at it, causing it to decompose and release carbon dioxide," researcher Aron Stubbins, from the University of Georgia Skidaway Institute of Oceanography, said in a statement. "The same thing happens to permafrost when it thaws."
Scientists have long feared that as the world gets warmer, thawing permafrost may lead to a significant effect on global warming. That's because according to estimates, there is more than 10 times the amount of carbon in Arctic soil than has been put into the atmosphere by burning fossil fuels since the start of the Industrial Revolution.
In other words, there is two and a half times more carbon locked away in the Arctic than there is in the atmosphere today.
And now, climate change is not only melting Arctic sea ice, but also the Arctic's deep freezer, threatening to release massive amounts of long-frozen carbon into the environment.
"The study we did was to look at what happens to that organic carbon when it is released," Stubbins said. "Does it get converted to carbon dioxide or is it still going to be preserved in some other form?"
To find out, Stubbins and his colleagues studied thawed permafrost near the Kolyma River at Duvanni Yar in Siberia. The researchers measured the carbon concentration, how old the carbon was, and what forms of carbon were present in the water. After adding local microbes to water samples, two weeks later they measured the changes in the carbon concentration and composition, as well as the amount of CO2 that had been produced. (Scroll to read on...)
"We found that decomposition converted 60 percent of the carbon in the thawed permafrost to carbon dioxide in two weeks," Stubbins said. "This shows the permafrost carbon is definitely in a form that can be used by the microbes."
"Interestingly, we also found that the unique composition of thawed permafrost carbon is what makes the material so attractive to microbes," added lead author Robert Spencer, from Florida State University.
These results confirm what scientists had feared. What's worse is that the carbon being broken down by the bacteria is at least 20,000 years old. That means this carbon has not been a part of the global carbon cycle for thousands of years, and releasing it now could have devastating consequences.
"If you cut down a tree and burn it, you are simply returning the carbon in that tree to the atmosphere where the tree originally got it," Stubbins explained. "However, this is carbon that has been locked away in a deep-freeze storage for a long time. This is carbon that has been out of the active, natural system for tens of thousands of years. To reintroduce it into the contemporary system will have an effect."
In addition, this massive release of carbon will only perpetuate climate change due to what scientists call a positive feedback loop. As the world continues to warm and Arctic permafrost thaws, more carbon will be released into the atmosphere, increasing climate warming. That, in turn, would cause more permafrost to thaw and release more carbon, causing the cycle to continue.
"Currently, this is not a process that shows up in future (Intergovernmental Panel on Climate Change) climate projections; in fact, permafrost is not even accounted for," Spencer pointed out. "Moving forward, we need to find out how consistent our findings are and to work with a broader range of scientists to better predict how fast this process will happen."
While these findings, described in the journal Geophysical Research Letters, sound like a recipe for imminent disaster, there may be one small glimmer of hope. Nature World News previously reported how Arctic permafrost may actually help us adapt to climate change.
This may seem to contradict this latest study's findings; however, scientists explain that permafrost soils may release greenhouse gases like CO2 gradually over time, and not all at once as previously believed. This prolonged release may in turn buy humanity some time to figure out how to deal with climate changes.
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