A recent study demonstrated that ancient permafrost transforms into carbon dioxide extremely quickly when thawed.
There are giant stores of carbon trapped in the permafrost that has been accumulating in the coldest regions of the world for thousands of years, the University of Colorado at Boulder reported. These carbon stores have remained relatively isolated from today's carbon cycle, but if they were to melt, the greenhouse gas they would release could have a major impact on the environment.
"Many scientists worldwide are now investigating the complicated potential end results of thawing permafrost," said Rob Striegl, USGS scientist and study co-author. "There are critical questions to consider, such as: How much of the stored permafrost carbon might thaw in a future climate? Where will it go? And, what are the consequences for our climate and our aquatic ecosystems?"
To answer some of these questions, a team of researchers looked at how quickly dissolved organic carbon from35,000-year-old permafrost decomposed and how much carbon dioxide it produced. The team studied a specific type of permafrost called Yedoma that is found in Alaska and Siberia and makes up a large amount of the permafrost soil carbon pool.
"It had previously been assumed that permafrost soil carbon this old was already degraded and not susceptible to rapid decomposition upon thaw," said Kim Wickland, the USGS scientist who led the team.
The study showed more than half of the dissolved organic carbon in yedoma permafrost decomposed within only a week of thawing, and about 50 percent of the present carbon was converted into carbon dioxide. These findings represent some of the fastest carbon conversion rates to ever be seen by science
"What this study adds is that we show what makes permafrost so biodegradable," said Travis Drake, the lead author of the research. "Immediately upon thaw, microbes start using the carbon and then it is sent back into the atmosphere."
The findings were published in a recent edition of the journal Proceedings of the National Academy of Sciences.
