Permafrost thawing in the Arctic could produce much higher levels of carbon emissions than previously estimated due to abrupt thawing in the region, according to a new study published in Nature.
Most of the Artic's permafrost — ground that remains frozen for at least two years straight — thaws gradually, and it's been projected to release 200 billion metric tons of carbon into the atmosphere by the year 2300.
However, around 20% of the permafrost in the Arctic is susceptible to rapid thawing, especially permafrost predominantly made up of ice. These sections of permafrost could emit an additional 60 to 100 billion metric tons of carbon into the atmosphere by 2300, according to the study.
Abrupt thawing of permafrost can cause rapid landscape changes that accelerate carbon emissions. For example, as the ice in the ground melts, the land can sink or “subside” and then flood, turning into a lake or wetland. These wetlands, in turn, might produce large amounts of methane, a more potent greenhouse gas than carbon dioxide.
“With abrupt thaw, you're exposing deeper layers to much warmer temperatures, and deep layers in permafrost can contain very high amounts of carbon,” Northern Arizona University biogeochemist and plant ecophysiologist Christina Schaedel, told Wired.
It's the perfect morning for a permafrost twitter-tour!— Dr. Merritt Turetsky (@queenofpeat) May 1, 2019
So what is permafrost? Permafrost is frozen ground that remains in a frozen state for multiple years. But it's way more complicated than that. You can be walking on permafrost & not even know it. Image: C.Buddle, McGill pic.twitter.com/r1YdwDxykS
Permafrost thawing is a dangerous climate feedback loop. As permafrost thaws, it releases greenhouse gas emissions into the atmosphere, which in turn accelerates global warming, leading to more permafrost thawing.
In addition to greenhouse gas emissions, these dramatic landscape changes can harm the communities living in the Arctic, the study said.
Sinking land can cause roads to buckle and homes to sink, and for families who traditionally hunt for food, it makes traversing the land more difficult. Landslides and rapid erosions of hills can also occur following abrupt permafrost thawing.