Beneath the sub-Arctic land of Alaska lies an ancient, frozen well of carbon dioxide contained in dead organisms: permafrost. That permafrost may soon thaw, and when it does, it may exacerbate habitat loss and global warming.
Scientists predict that permafrost melt alone could raise global temperatures up to 1.7 degrees Fahrenheit over the next few centuries. Researchers at the Woods Hole Research Center in Alaska say thawing of permafrost is the most dire issue in tackling climate change in the region, according to an interactive article from The New York Times.
Permafrost can range from extending a few feet below the surface to several thousand feet. Permafrost lies under 20-25 percent of the Earth's surface and under 40-50 percent of Canada, according to Radio Canada International.
The ice thaws each summer as the temperature warms and becomes completely solid in winter. As global temperatures have risen, the area of thaw becomes deeper each year -- over time, permafrost is weakened.
While scientists agree that full thawing of all permafrost could not occur in the conceivable future, the temperature rise is already beginning to take a toll on the environment.
Some changes in permafrost depth and composition are observable to the naked eye. In the largely-treeless area about 350 miles of the Arctic Circle, where temperatures are half a degree below the freezing point, banks around lakes have began to cave in and depressions are forming.
"[This thawing] has all kinds of consequences both locally for this region, for the animals and the people who live here, as well as globally," said Max Holmes, Woods Hole senior scientist and deputy director. Holmes added that it was "sobering" to see how quickly the landscape has changed.
Towns are also seeing the effect of the melt. In Bethel, Alaska, buildings and roads have begun to sink. Some of the town's infrastructure is reinforced with liquid-filled pipes that transfer heat from the ground and prevent it from collapsing.
Up North, where permafrost is deeper, scientists are still seeing changes. Vladimir E. Romanovsky of the University of Alaska, Fairbanks claims that temperatures have risen by 5.5 degrees Fahrenheit 65 feet below the ground.
Romanovsky contends that permafrost surface temperatures at some Northern locations could rise above freezing by the middle of the 21st century.
The most common greenhouse gases released by permafrost melt are carbon dioxide and methane. Scientists must take ice cores to analyze the carbon content and chemical makeup of the ice, which helps them determine what kinds of greenhouse gases will be released.
Although estimates of the total amount of carbon that will be released by permafrost melt vary, one calculation places is at 1.5 billion tons per year, roughly the amount that is released annually by fossil-fuel burning in the U.S.
A separate, federal report released in early August concluded that Alaska and the Arctic have warmed at more than double the rate of annual global warming, KTUU reports.
"It is virtually certain that human activities have contributed to Arctic surface temperature warming, sea ice loss since 1979, glacier mass loss, and northern hemisphere snow extent decline observed across the Arctic," the report notes.
According to a 2017 study reported by Radio Canada International, scientists estimate that more than 770,000 square miles of permafrost could be saved if the world’s temperature remains under 1.5 degrees Celsius (2.7 degrees Fahrenheit) rather than 2 degrees Celsius (3.6 degrees Fahrenheit), the goal of the Paris Climate Agreement, according to the European Commission.