Schaefer and his team ran multiple Arctic simulations assuming different rates of temperature increases to forecast how much carbon may be released globally from permafrost in the next two centuries. They estimate a release of roughly 190 billion tons of carbon, most of it in the next 100 years. The team used Intergovernmental Panel on Climate Change scenarios and land-surface models for the study.
"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," said Schaefer. The amount of carbon predicted for release between now and 2200 is about one-fifth of the total amount of carbon in the atmosphere today, according to the study.
While there were about 280 parts per million of CO2 in Earth's atmosphere prior to the Industrial Age beginning about 1820, there are more than 380 parts per million of carbon now in the atmosphere and the figure is rising. The increase, equivalent to about 435 billion tons of carbon, resulted primarily from human activities like the burning of fossil fuels and deforestation.
Using data from all climate simulations, the team estimated that about 30 to 60 percent of Earth's permafrost will disappear by 2200. The study took into account all of the permanently frozen ground at high latitudes around the globe.
The consensus of the vast majority of climate scientists is that the buildup of CO2 and other greenhouse gases in Earth's atmosphere is the primary reason for increasingly warm temperatures on Earth. According to NOAA, 2010 was tied for the hottest year on record. The hottest decade on record occurred from 2000 to 2010.
Greater reductions in fossil fuel emissions to account for carbon released by the permafrost will be a daunting global challenge, Schaefer said. "The problem is getting more and more difficult all th
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University of Colorado at Boulder