Up to two-thirds of Earth's permafrost likely will disappear by 2200 as a result of warming temperatures, unleashing vast quantities of carbon into the atmosphere, says a new study by the University of Colorado Boulder's Cooperative Institute for Research in Environmental Sciences.
The carbon resides in permanently frozen ground that is beginning to thaw in high latitudes from warming temperatures, which will impact not only the climate but also international strategies to reduce fossil fuel emissions, said CU-Boulder's Kevin Schaefer, lead study author. "If we want to hit a target carbon dioxide concentration, then we have to reduce fossil fuel emissions that much lower than previously thought to account for this additional carbon from the permafrost," he said. "Otherwise we will end up with a warmer Earth than we want."
The escaping carbon comes from plant material, primarily roots trapped and frozen in soil during the last glacial period that ended roughly 12,000 years ago, he said. Schaefer, a research associate at CU-Boulder's National Snow and Ice Data Center, an arm of CIRES, likened the mechanism to storing broccoli in a home freezer. "As long as it stays frozen, it stays stable for many years," he said. "But if you take it out of the freezer it will thaw out and decay."
While other studies have shown carbon has begun to leak out of permafrost in Alaska and Siberia, the study by Schaefer and his colleagues is the first to make actual estimates of future carbon release from permafrost. "This gives us a starting point, and something more solid to work from in future studies," he said. "We now have some estimated numbers and dates to work with."
The new study was published online Feb. 14 in the scientific journal Tellus. Co-authors include CIRES Fellow and Senior Research Scientist Tingjun Zhang from NSIDC, Lori Bruhwiler of the National Oceanic and Atmospheric Administration and Andrew Barrett from NSIDC.
|Contact: Kevin Schaefer|
University of Colorado at Boulder