FAIRBANKS, Alaska — In parts of Alaska, the ground is sinking so much that trees are growing almost horizontally. It's an area scientists refer to as a "drunken forest."

Researchers at NASA's Jet Propulsion Laboratory are only beginning to understand the severity of the situation. They're awaiting the results from their second yearly flight over the boreal forests of northern Alaska to look for changes in the layer of frozen soil at the root of the problem: melting permafrost.

A change in the depth of the permafrost could have frightening consequences for the climate.

Massive stores of carbon — in the form of ancient flora and fauna — are frozen in the Arctic ground. As the ice in the permafrost melts, microbes in the soil consume that carbon and convert it into carbon dioxide and methane, two major greenhouse gases, which rise into the atmosphere.

“There's approximately 1,000 billion metric tons of organic carbon in the top three meters of soil in the permafrost,” said Charles Miller, the lead NASA climate scientist with the Arctic Boreal Vulnerability Experiment. “To put that in context, there's approximately 350 billion tons of carbon that's been released into the atmosphere from all of the human activity since the beginning of the industrial revolution. So about 3 times that amount is in those top 3 meters of permafrost.”

Recent studies, including last week's alarming United Nations climate report, have suggested the amount of green house gases released into the atmosphere from permafrost thaw has been rising as the planet warms.

"We've seen over the last 30 or 40 years, long-term records, that the temperature of the permafrost is rising dramatically," Miller said. "That can signal that we’re seeing the onset of what could be widespread permafrost thaw across the Arctic."