Permafrost is any type of ground that has been frozen continuously for a minimum of two years and as many as hundreds of thousands of years. It currently covers a region of about nine million square miles in the Northern Hemisphere. This is nearly the size of the US, Canada, and China combined. It can also extend beneath our planet’s surface from a few feet to more than a mile. However, this once extremely thick frozen ground is rapidly thawing due to climate change.
A 2019 study conducted by researchers from the University of Alaska Fairbanks reported that permafrost in the Canadian Arctic is thawing 70 years earlier than predicted. They were surprised by how the permafrost that has been frozen for millennia was destabilized. “What we saw was amazing. It’s an indication that the climate is now warmer than at any time in the last 5,000 or more years,” said Vladimir Romanovsky, a professor of geophysics at the university.
Permafrost is extremely important for the Arctic region. It acts like a giant freezer, which keeps microbes, carbon, poisonous mercury, and soil locked in place. But with the rising temperatures, the long-dormant microbes are starting to wake up. At the same time, scientists fear that thawing permafrost could contribute to global warming and climate change because there’s more carbon stored in the permafrost than in the atmosphere.
The 2019 report from the UN’s Intergovernmental Panel on Climate Change also revealed that permafrost temperatures are increasing. According to Vox, a liberal-leaning American news and opinion website, around 25% of the permafrost near the surface could be lost even if the world manages to hit the IPCC target of limiting global warming to 2 degrees Celsius by 2100.
Additionally, a 2011 report by the National Oceanic and Atmospheric Administration (NOAA) and the National Snow and Ice Data Center (NSIDC) predicted that permafrost will change the Arctic from a carbon sink to a source after the mid-2020s. This will be strong enough to cancel 42% or 88% of the total global land sink. According to ThinkProgress, an American progressive news website, if this happens, the thaw and decay of permafrost carbon would be irreversible. This will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.
“If we want to hit a target carbon concentration, then we have to reduce fossil fuel emissions that much lower than previously calculated to account for this additional carbon from the permafrost,” lead author Dr. Kevin Schaefer said.
Thawing Permafrost Can Release Dangerous Gases
Permafrost has acted as a freezer for thousands of years, keeping 1,400 to 1,600 gigatons of plant matter carbon trapped in the soil. These billions of tons of carbon locked inside the permafrost are more than twice the amount of carbon currently in the atmosphere and mostly contain partially decayed remains of ancient plants and animals. As permafrost thaws rapidly, it can release vestiges of ancient life and masses of carbon that can significantly accelerate climate change.
A recent study published in Nature Geoscience showed that while abrupt permafrost thawing will happen in less than 20% of frozen land, it will increase permafrost carbon release projections by about 50%. "Under all future warming scenarios, abrupt thaw leads to net carbon losses into the atmosphere," lead author Merritt Turetsky, the head of the Institute of Arctic and Alpine Research in Boulder, Colorado, said.
According to Science Alert, a leading scientific publisher dedicated to publishing peer-reviewed significant research work, researchers estimated that abrupt permafrost thawing could release 60 to 100 billion tons of carbon by 2300. One ton of carbon is equivalent to 3.67 tons of carbon dioxide. This is equivalent to about eight years of global emissions at current rates. "This is in addition to the 200 billion tons of carbon expected to be released in other regions that will thaw gradually," Turetsky added.
Unfortunately, carbon isn’t the only gas trapped in the permafrost. A 2019 study published in Geophysical Research Letters revealed that the Arctic permafrost is the largest repository of mercury on Earth. Researchers believe that there are around 15 million gallons of frozen mercury in permafrost soils, which is almost twice the amount found in all other soil, the ocean, and the atmosphere combined.
“The release of heavy metals, particularly mercury, and other legacy contaminants currently stored in glaciers and permafrost is projected to reduce water quality for freshwater biota, household use, and irrigation,” the report said.
Thawing Permafrost Can Transform the Arctic
A 2019 study published in Nature Communications reported that the thawing permafrost will cause about 5% amplification of global warming, adding up to about $70 trillion to the world’s climate bill. According to The Guardian, an online British site, researchers analyzed known stocks of frozen organic matter in the ground up to three meters deep at multiple points across the Arctic. After that, they used the world’s most advanced simulation software in the US and at the UK Met Office to predict how much gas will be released at different levels of warming.
The costs of the global climate-driven impacts are projected to add to global inequality because most of the economic burden is likely to be carried by countries in warmer but poorer regions such as India and Africa. “Even at 1.5 degrees C to 2 degrees C, there are impacts and costs due to thawing permafrost. But they are considerably lower for these scenarios compared to business as usual. We have the technology and policy instruments to limit the warming but we are not moving fast enough,” author Dmitry Yumashev of Lancaster University said.
Aside from that, studies showed that the rapid melting of permafrost can dramatically reshape the Arctic landscape in just a few months. According to Yale Environment 360, an online magazine offering an opinion, analysis, reporting, and debate on global environmental issues, as permafrost thaws and slumping expands, parts of that landscape are being transformed into nothing but mud, silt, and peat. This can swallow up dozens of buildings that can result in an environmental disaster.
Additionally, scientists stated that 40% of the world’s permafrost could disappear if the Arctic continues to warm as quickly as climatologists are predicting. This will result in landscape changes that can alter ecosystems, making it increasingly difficult for indigenous people to find food and shelter. Currently, the thawing permafrost is triggering landslides and slumping at alarming rates, resulting in stream flows changing, seashores collapsing, and lakes suddenly draining.
“We’re seeing slumping along shorelines that can drain most of the water in a lake in just days and even hours. It’s not surprising when you consider that as much as 80% of the ground here consists of frozen water. When that ice melts, the frozen ground literally falls apart,” said Canadian scientist Philip Marsh.
Thus, scientists urge governments to better understand how a warming climate is impacting water resources and permafrost ecosystems.