Scientists are working in Alaska to ascertain the potential impact of greenhouse gases being released into the atmosphere from the arctic's permafrost.

The New York Times reported Friday scientists now estimate the frozen north contains twice as much carbon as the entire atmosphere. With temperatures rising in the region, the researchers are trying to determine how much of the trapped carbon is being released and what the impact will be on global warming, particularly if it enters the atmosphere as methane gas rather than carbon dioxide.

The Times said initial computer projections that indicated the arctic and subarctic regions could eventually release 15 percent of the amount of emissions human activities produce could be low. A recent survey of 41 permafrost scientists suggests if the burning of fossil fuels remains high and the planet warms sharply, the gases from permafrost could eventually equal 35 percent of today's annual human emissions, the newspaper said.

The scientists also said the releases from permafrost could be kept to 10 percent of today's man-made emissions, if those emissions are brought under control soon.

The breakdown of permafrost carbons is projected to be a century or more away. However, the fear is that once decomposition starts, there will be no way to slow it down, the Times said.

"Even if it's 5 or 10 percent of today's emissions, it's exceptionally worrying, and 30 percent is humongous," Australian greenhouse gas researcher Josep G. Canadell said. "It will be a chronic source of emissions that will last hundreds of years."