Thawing permafrost will release carbon

BOULDER, Colo., Feb. 16 (UPI) -- Up to two-thirds of the Earth's permafrost could thaw by 2200 because of warming temperatures, releasing carbon into the atmosphere, U.S. scientists said.

The study by the University of Colorado Boulder's Cooperative Institute for Research in Environmental Sciences indicated the higher levels of carbon would impact not only the climate but also global strategies to reduce fossil fuel emissions, lead author Kevin Schaefer said Wednesday in a release.

"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," said Schaefer a research associate at CU-Boulder's National Snow and Ice Data Center. "Otherwise we will end up with a warmer Earth than we want."

The escaping carbon is from plant material trapped and frozen in soil during the last glacial period that ended about 12,000 years ago, said Schaefer, comparing the process to storing broccoli in a 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."

Schaefer said his team ran simulations with different rates of temperature increases to calculate how much carbon may be released from thawing permafrost in the next two centuries. The team estimated about 190 billion tons of carbon would be released, most of it in the next 100 years.

"The amount we expect to be released by permafrost is equivalent to half of the amount of carbon released since the dawn of the Industrial Age," he said.

The study was published online Monday in the scientific journal Tellus.