Five new studies that change our understanding of permafrost

Why they matter, even if you don’t live in the Arctic.

 

On July 16, 2007, a rare bolt of lighting touched down on a remote, lake-studded expanse of tundra about 350 miles south of the Arctic Ocean. It had been a hot, dry summer, and the tundra ignited into what would eventually become its largest blaze in 5,000 years. Over the next three months, the Anaktuvuk River Fire scorched an area the size of Cape Cod. Its scar was visible from space. 

In its wake, scientists flocked to the burned tundra to find out how plants, wildlife and soils respond to an ecological regime that’s likely to become the new normal: a hotter, drier and more fire-prone Arctic.

Now, the results from those studies (and numerous others) are beginning to trickle in. And while some are of limited interest to those of us below the Arctic Circle, discoveries about thawing permafrost have the potential to impact people and environments the world over. That’s because permafrost — the frozen soil that can stretch as much as 650 meters below the tundra’s surface — contains a third of the planet’s land-based carbon.

Until recently, relatively little was known about the repercussions of thawing permafrost. Today, as its role in global carbon cycles grows increasingly apparent, a slew of studies are transforming our understanding of the north’s frozen soil. Here are five of the most notable: 

Naturally occurring polygons, a sign of continuous permafrost, in Alaska's Arctic.
Western Arctic National Parklands.

The study: “Recent Arctic tundra fire initiates widespread thermokarst development,” Nature, Oct. 2015. 

Takeaway: Tundra fires, which are becoming increasingly common, strip away protective vegetation and contribute to substantial thawing.

More: Researchers led by the United States Geological Survey used LIDAR (aerial laser mapping technology) to study thermokarst — the slumped, irregular topography that follows permafrost thaw — after the Anaktuvuk River Fire. They detected permafrost thaw in 34 percent of land affected by the fire, compared to 1 percent elsewhere.


The study: “Distribution of near-surface permafrost in Alaska: Estimates of present and future conditions,” Remote Sensing of Environment, Oct. 2015. 

Takeaway: Between 16 and 24 percent of Alaska’s permafrost will disappear by the end of the century.  

More: USGS researchers used data from 17,000 locations to create an unprecedented map of permafrost in Alaska, and quantify for the first time just how much of that permafrost will likely vanish. And while it considers a variety of climate scenarios, the study doesn’t take into account increased fire or other positive feedback loops, meaning it could be conservative.  


The study: “Ancient low-molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw,” The Proceedings of the National Academy of Sciences, Sept. 2015. 

Takeaway: Scientists had assumed that 35,000-year-old permafrost was already largely decomposed, but it turns out that’s not true. When it thaws, ancient frozen soil still converts some 25 percent of its organic carbon to atmospheric carbon dioxide.

More: In 2012, the U.S. Army Corps of Engineers began expanding an existing underground tunnel in the permafrost near Fairbanks. The new tunnel provided access to a certain type of ancient permafrost called yedoma that stores vast amounts of carbon in Alaska and Siberia. Scientists had believed thawing yedoma wouldn’t contribute much in the way of greenhouse gases, but this study shows that to be untrue: half of the dissolved organic carbon in yedoma decomposed within a week, and half of that turned into carbon dioxide. 


The study: “Economic impacts of carbon dioxide and methane released from thawing permafrost,” Nature Climate Change, Sept. 2015.

Takeaway: Thawing permafrost could cost the world $43 trillion by the year 2200. 

More: Researchers from the University of Cambridge and the National Snow and Ice Data Center used various models from the Intergovernmental Panel on Climate Change to measure the economic impact of the billions of tons of carbon dioxide emitted from thawing permafrost. The $43 trillion assumes increased anthropogenic emissions until 2100, and zero emissions thereafter. 


The study: “Climate change and the permafrost carbon feedback,” Nature, April 2015.

Takeaway: Instead of an explosive ‘carbon bomb’ released all at once, the carbon stored in permafrost is likely to trickle into the atmosphere gradually. 

More: Scientists with the Permafrost Carbon Network estimate that altogether, the amount of carbon predicted to escape within the next 85 years is the equivalent of 10 percent of the current emissions from fossil fuels. While that’s good news in the short term, it means future generations will have to deal with the bulk of greenhouse gases leaking from thawing permafrost. 

Krista Langlois is a correspondent at High Country News.