• This field is for validation purposes and should be left unchanged.
  • Earth.Org Newsletters

    Get focused newsletters especially designed to be concise and easy to digest

  • This field is for validation purposes and should be left unchanged.
SHOP Support

Permafrost is a ground layer under the Earth’s surface that has been frozen for a minimum of two years and as many as hundreds of thousands of years. However, warming temperatures under climate change is causing this permafrost to melt. Unfortunately, this is leading to an acceleration of climate change as the thawing soil releases greenhouse gases (GHGs), particularly methane, a gas with more potency than carbon dioxide. 

Permafrost is predominantly found in the northern hemisphere, constituting 25% of the ground type found there. Key areas for permafrost are the Arctic regions of Siberia, Canada, Greenland and Alaska. In the southern hemisphere, there is far less permafrost extent, however, some is found in the mountainous areas of the Andes, New Zealand’s Southern Alps and Antarctica. 


Modelled permafrost extent (2000-2016) from Obu et al. (2019)

As global temperatures rise due to global warming, there are a range of temperature predictions for future global average temperature increase depending on our emission pathway scenarios. However, as this is a global average, it doesn’t accurately represent how some areas will warm more than others. The Arctic is predicted to warm more drastically than any other area on the planet. This is evidenced not only by climate models predicting the future, but by observations over the last 30 years: the Arctic has warmed at roughly twice the rate of the rest of the globe, in a process known as Arctic amplification. This phenomena is caused by the retreat of sea ice as open water reflects less incoming radiation than the white sea ice, and by atmospheric heat transport from the equator.

While this phenomena presents a myriad of environmental issues, such as sea ice retreat and sea level rise, increasing temperatures are also resulting in a rapid thawing of permafrost. Permafrost contains a high content of frozen organic material. If this material thaws, it will begin to decompose, which releases GHGs, such as carbon dioxide and methane. Permafrost is one of the planet’s carbon sinks, storing around 1 400 Gt of carbon dioxide. Since 2018 humans have been pumping about 30-35Gt of carbon dioxide into the atmosphere per year, (down from 36.15Gt in 2017), and the planet is experiencing unprecedented warming. It is predicted that 3°C of warming by the end of the century will put about 280Gt of carbon dioxide and 3Gt of methane into the atmosphere from melting permafrost, with the warming effect of methane being 10-20 times greater than carbon dioxide. The additional GHGs in the atmosphere are accelerating climate change and the warming of the planet, which accelerates permafrost thaw further. This is known as a positive feedback mechanism. 


Infographic from NOAA Climate.gov and permafrost map by National Snow and Ice Data Centre, showing how permafrost works as a positive feedback mechanism

Permafrost thaw is an international issue that is accelerating each year. However, the urgency of the issue is prompting some solutions. For example, engineering-based solutions in the form of methane capture and transformation into energy is one idea, but due to the economic and logistical challenges, it is an idea in its infancy. 

However, there are some nature-based solutions that may be able to have local impact. For example, through habitat restoration. Sergey Zimov, a geophysicist and specialist in subarctic ecology, began working on Pleistocene Park, a scientific research station and nature reserve, assessing the benefits of ecosystem restoration on permafrost preservation, carbon sequestration and the albedo effect. Founded in 1996, Zimov ceded the project to his son and fellow scientist, Nikita Zimov, who focuses more on climate change prevention than Pleistocene ecology, saying that “there is only one theoretical chance to prevent that [permafrost thaw] from happening. We must restore the Ice Age ecosystem.” The pair believe returning grazing animals, similar to those found in the Pleistocene era to replace herds of bison, musk ox, reindeer, moose and woolly mammoths, would compact the snow during winter months. In theory, the increase in grazing animals in arctic regions would increase the compaction of the thin layer of snow, increasing the layer’s density, allowing for deeper freezing of the soil underneath, essentially protecting and strengthening the permafrost layer. However, this type of project proposes a multitude of unknown risks that accompany species reintroductions and rewilding projects

Similarly, researchers at the University of Edinburgh have investigated the novel approach of using plants to control the temperature of soils. By planting communities of trees, shrubs and mosses over permafrost layers, the plants can shade soil, lowering temperatures, and also extract water through their roots, which dries the soil allowing it to act as a better insulator. However, the research is in very early stages and requires a deeper understanding of how these different plant types interact with permafrost.

Overall, a simple way to reduce global warming is to reduce global GHG emissions in order to reduce the greenhouse effect. However, there are many political, social, economic and technological barriers that are preventing us from moving to a carbon neutral society. The challenge is not impossible and is the most feasible way to limit the loss of permafrost, and therefore, acceleration of climate change. 

A crater at least 50 meters deep and 20 meters wide has been spotted in the tundra region in Siberia. Scientists are not sure how the hole- at least the ninth spotted in the region since 2013, and so far one of the largest- formed, however they believe it is linked to a buildup of methane that exploded, a frightening result of warming temperatures in the region. 

The crater was discovered accidentally by a Russian film crew earlier this year as they were flying over the Yamal peninsula in Siberia on an unrelated assignment. 

Evgeny Chuvilin, lead research scientist at the Skolkovo Institute of Science and Technology’s Center for Hydrocarbon Recovery, who visited the site of the newest crater to study it, says, “Right now, there is no single accepted theory on how these complex phenomena are formed. It is possible they have been forming for years, but it is hard to estimate the numbers. Since craters usually appear in uninhabited and largely pristine areas of the Arctic, there is often no one to see and report them. Even now, craters are mostly found by accident during routine, non-scientific helicopter flights or by reindeer herders and hunters.” 

You might also like: Alarm as Siberia Experiences Heatwave, With Temperatures 10℃ Above Average

siberia crater
An aerial view of the newest crater that has appeared this year in Siberia. It is one of the largest that has appeared so far. Image by: Evgeny Chuvilin.

How Do These Craters Form?

Permafrost, making up two-thirds of Siberia, is a huge natural reservoir of methane. Recent hot summers in the region, including in 2020, may have contributed to the creation of these craters. 

Methane- and other gases- can accumulate in the upper layers of this permafrost, which can create pressure that is strong enough to burst through the upper layers of frozen ground, scattering earth and rocks and creating craters, in a process called “cryovolcanism.” These craters turn into lakes within two years of being formed. 

Researchers studied the newest crater and older ones, and found that mounds in the Earth formed just before the explosions. The craters were also all located on gentle slopes and had a lower portion that was cylindrical before opening into a funnel, with the opening around 20 to 25 meters wide. 

They believe that extremely hot summers in the region in 2012 and 2016, and again in 2020, may have contributed to the growth and blowout of these mounds, which appear and explode within as little as three to five years. 

Methane accumulates in a process called “cryopeg”- a layer of unfrozen ground that never freezes because of its salt content below a table of ground ice- and acts as a trap. The gas escapes, forming a mound. When warm summers occur, the mound blows, creating the craters. Scientists say that as temperatures rise around the world and the climate continues to warm, melting permafrost is becoming more common and is therefore leading to more crater formations.

None of these features have been discovered or reported in the Alaskan or Canadian arctic. Researchers believe that the crater formations are unique to the Arctic region in Siberia because few other areas share the features believed to be necessary for them to form- a combination of table-like ground ice close to the surface, continuous permafrost with methane and unfrozen ground with saline deposits below the ice. 

How Are They Linked to the Climate Crisis?

This year, Siberia experienced a prolonged heatwave, with unusually high temperatures linked to wildfires and a huge oil spill. Climate scientists called it “alarming” and believed that it would push the planet towards its hottest year on record. Towns in the area recorded extraordinarily high temperatures, with Nizhnyaya Pesha hitting 30℃ on June 9 and Khatanga, which usually has temperatures of around 0℃ that time of year, hitting 25℃ on May 22. The highest temperature recorded previously was 12℃.

If linked to the climate crisis, these conditions would have certainly contributed to the blowout of the mounds. 

Some experts, however, aren’t convinced that the progressing climate crisis is causing these craters. Anecdotal evidence suggests that explosions creating craters in the tundra have been happening for generations. They instead suggest the cause of the craters to be gas trying to move to the surface from deep layers of the Earth. Others believe that the climate crisis plays a role, but that more data is needed to say definitively. 

Chuvilin has promised that his team will publish more detailed information on this phenomenon in an upcoming scientific journal. 

Professor Vasily Bogoyavlensky, Doctor of Engineering Sciences from the Russian Academy of Sciences, says that there are more than 7 100 heave mounds on the Yamal and Gydan peninsula and that 5-6% of these are “really dangerous.” He adds that researchers are currently working to understand which heave mounds will explode and which will not. They are also considering ways of neutralising those with the potential to explode. 

Featured image by: Dmitry Semenov

The first active leak of methane from the sea floor in Antarctica has been discovered by scientists. Worryingly, the scientists also found that the microbes that normally consume the gas before it reaches the atmosphere had only congregated in small numbers after five years, allowing the methane to escape. What does this mean for the planet in its mission to mitigate the climate crisis?

The Antarctica Methane Release

The research, published in the journal Proceedings of the Royal Society B, reports the discovery of the methane seep at a site called Cinder Cones in McMurdo Sound. The site is 10 metres deep with a 70 metre long patch of white microbial mats. This seep was first spotted by divers in 2011 and scientists returned to the site in 2016 to study it in detail, before beginning laboratory work.

The researchers are unsure of the reason for the emergence of this new seep, but believe that it is ‘probably not global heating’ as the Ross Sea where it was found has yet to warm significantly. They are most concerned, however, about the delay of the microbes in consuming the methane, which current climate models do not take into account. Andrew Thurber, from Oregon State University, who led the research, says, “The delay in methane consumption is the most important finding. It is not good news. It took more than five years for the microbes to begin to show up and even then there was still methane rapidly escaping from the sea floor.” 

You might also like: Antarctica Heatwave: When, Why and What it Means

However, Thurber says that while very little is known about the Antarctic methane cycle, the new seep provides a natural laboratory for further research.

The source of the methane, which was found to be dissolved in the water instead of bubbling, is probably decaying algae deposits buried under sediments and is likely to be thousands of years old. The slow growth of microbes at the site means that methane is certainly leaking into the atmosphere. Thurber believes that it may be ‘five to 10 years’ before a community of microbes becomes fully adapted and starts consuming methane. 

Antarctica is known as the ‘black hole’ of research in understanding the Earth’s methane cycle, as it is generally a difficult place to work, according to scientists. Vast amounts of methane are thought to be stored under the sea floor around Antarctica which is released from frozen underwater stores or permafrost regions. This process is one of the key tipping points of the climate crisis as methane is a greenhouse gas that is far more potent than carbon and could have catastrophic impacts on the planet and the environment.

The team says that this discovery may not be an anomaly, and they wonder if these features are more common than we think around Antarctica, but are rarely stumbled upon. 

A recent study found that the South Pole has warmed at a rate three times the global average over the past 30 years, prompting fears that methane could be released in larger quantities as the oceans in the region warms. 

The continent also experienced unprecedented heat last summer and in February, recorded a temperature of 20.75°C, Antarctica’s highest temperature in recorded history. This has exacerbated the rapid melting of the Thwaites Glacier, an unusually large and vast ice sheet in Antarctica that is nicknamed the “Doomsday Glacier” for the devastating consequences it could have on global sea level rise. 

While this methane discovery may be a natural phenomenon and not necessarily caused by human activity, the effects of it will surely be worse than if humanity mitigated its greenhouse gas emissions. As natural feedback loops are initiated, this has never been more important. 

With global temperatures on the rise, scientists are concerned that the thawing of the Arctic permafrost will release alarming levels of methane into the atmosphere. However, new research has found a bacteria that ‘eats’ methane, preventing much of the gas from entering the atmosphere.

Methane is a greenhouse gas that is more potent than carbon dioxide, as it is much more efficient at trapping radiation. Despite its lifetime in the atmosphere being comparatively shorter, pound for pound, the impact of methane on global warming over a 100 year period is 25 times greater than carbon dioxide. Globally, it has been found that 50-65% of total methane emissions originate from human activity, namely through the use of fossil fuels, landfills and agricultural practices.

Methane-consuming Bacteria

Recently, a study published in Natural Climate Change has discovered high-affinity methanotrophs (HAMs, otherwise known as methane-oxidising bacteria), in Arctic mineral soils. More specifically, methanotrophs are a unique type of bacteria capable of using methane as their only source of energy. They are often found in environments like peatlands, rice paddies, hot springs and mud pots. As they are key players in the Earth’s natural methane cycle, where methane produced in soils remains trapped between soil particles, methanotrophs can thus consume the gas, preventing the release of methane into the atmosphere. In wetland environments, it has been estimated that around 40-60% of the methane produced is consumed by these microbes before escaping into the atmosphere. Therefore, these bacteria are of great interest to researchers studying global warming. It has been suggested that methanotrophs could potentially decrease overall net methane emissions, due to the increased productivity of the high-affinity methanotrophs. As such, net greenhouse gas emissions coming from the Arctic might end up being much smaller than previously modelled estimates. 

You might also like: How Singapore Aims to Secure its Food Supply With its ’30 by 30′ Plan

These findings are led by scientists QianLai Zhuang and Youmi Oh from Purdue University in Indiana. According to their research, whilst permafrost thaw increases methane production in Arctic wetlands as a result of methanogens, these organic-rich soils only comprise 13% of the total land area. The remaining 87% of the region is dominated by the mineral-rich soils that support HAMs.

Thus, researchers have argued this might explain why observed methane emissions have averaged 5 to 10 gigatons less per year than previous models have predicted. 

As Youmi Oh states, “We do believe that Arctic methane emissions will increase by the end of this century as other studies have shown, but the net increase to the atmosphere will be much smaller once upland methanotrophs are taken into consideration.” She also adds, “It was even possible in our simulation that net emissions decrease because high-affinity methanotrophs survive better than methanogens in response to warming.” More specifically, methanogens are microorganisms that produce methane as a result of energy metabolism. They are generally found in places where oxygen is lacking, such as underground, wetlands, oceans and even in intestines of all kinds of animals. 

Although smaller net methane emissions are a good thing, Zhuang and Oh both warn that this would depend on higher global temperatures. As Zhuang says, “it’s important to remember that this is only one part of the planet. It doesn’t account for greenhouse gases produced in other regions.” 

As of now, the researchers’ new model includes the role of HAMs as well as other variables such as microbial responses to a warmer Arctic. Zhuang and Oh will continue to monitor Arctic methane emissions in order to better improve their current model to provide more accurate projections. 

Other studies have also observed a huge spike in methane emissions in places like the East Siberian Arctic Shelf (ESAS), which were nine times greater than the average global atmospheric concentration. There have been concerns about the effect of the release of even a small fraction of methane which could trigger positive feedback loops, where methane coming from melting permafrost could trap more heat in the environment, furthering this thawing of thawing. 

In Professor Igor Semiletov’s own words, “This goes beyond geo-political considerations… We need to think about how to combine our efforts to study this, because it affects everyone.” 

Featured image by: Alaska Region U.S. Fish & Wildlife Service

Siberia is experiencing a prolonged heatwave, with unusually high temperatures linked to wildfires, a huge oil spill and a plague of tree-eating moths. Climate scientists have said this heatwave is ‘undoubtedly alarming’ and will push the world towards its hottest year on record. 

Russian towns in the Arctic circle have recorded extraordinarily high temperatures, with Nizhnyaya Pesha hitting 30℃ on June 9 and Khatanga, which usually has temperatures of around 0℃ this time of year, hitting 25℃ on May 22. The highest temperature recorded previously was 12℃. 

Throughout May, temperatures in parts of Siberia were up to 10C above average, according to the EU’s Copernicus Climate Change Service (C3S). The Danish Meteorological Institute said that these abnormal temperatures seen in north-west Siberia would be likely to happen once in 100 000 years without anthropogenic climate change.

You might also like: Climate Models Underestimate Carbon Emissions From Permafrost by 14%- Study

Freja Vamborg, a senior scientist at C3S, says, “Although the planet as a whole is warming, this isn’t happening evenly. Western Siberia stands out as a region that shows more of a warming trend with higher variations in temperature. So to some extent large temperature anomalies are not unexpected. However, what is unusual is how long the warmer-than-average anomalies have persisted for.”

Temperatures in the polar regions are increasing fastest because ocean currents carry heat towards the poles, melting reflective ice and snow rapidly.

From January to May, Russia experienced record high temperatures in 2020, with the average temperature 5.3℃ above the 1951-1980 average. 

Russian president, Vladimir Putin, commented on the heat, saying that some cities in Russia were built north of the Arctic circle on permafrost.

Causes of the Siberia Heatwave

Thawing permafrost is partly to blame for an oil spill in Siberia this month that prompted a national emergency being declared by the government. According to its operators, the supports of the storage tank suddenly sank, while green groups have also blamed poorly maintained infrastructure.

Wildfires have also torn through Siberia’s forests, ravaging hundreds of thousands of hectares. Fires are often started in the spring to clear vegetation, however high temperatures and strong winds associated with the heatwave in Siberia caused some fires to burn out of control.

Additionally, swarms of the Siberian silk moth, whose larvae eat conifer trees, have grown rapidly in warming temperatures. These larvae strip the trees of their needles and make them more susceptible to fires.

The planet is set to record its hottest year on record in 2020, despite a temporary dip in carbon emissions due to lockdown measures from the COVID-19 pandemic. 

Featured image by: Gael Varoquaux

A new study has found that climate change models have underestimated the amount of carbon emissions from thawing permafrost by as much as 14%. Current models do not take into account organic carbon released from thawing permafrost that is flushed into waterways and then converted into carbon dioxide by sunlight. 

How much carbon is stored in permafrost?

There are about 100 billion metric tons of carbon stored in Arctic permafrost. Scientists believe that 5-15% of this could be emitted as carbon dioxide by 2100. This, spurred by microbial action, could be enough to raise global temperatures by 0.3 to 0.4 degrees Celsius. However, these estimates do not include the carbon dioxide that forms when organic carbon escaping from permafrost soil is flushed into Arctic lakes and rivers and is oxidised by sunlight- a process called photomineralisation. 

Published in the journal Geophysical Research Letters, researchers at the University of Michigan studied organic carbon from six Arctic locations and found that a significant amount of carbon dioxide emissions could be released through photomineralistion, enough to raise permafrost-related carbon dioxide emissions by 14%. 

You might also like: Mangrove Trees Could Disappear by 2050 if Emissions Aren’t Cut

Rose Cory, an environmental scientist at the university who helped to lead the research, says, “Only recently have global climate models included greenhouse gases from thawing permafrost soils. But none of them contain this feedback pathway.”

This pathway has been debated because it can be difficult to measure exactly how sunlight interacts with soil carbon; each wavelength of light has a different effect on soil organic carbon. Cory and her team developed a tool that uses LED lights to measure the impacts of different wavelengths of light on organic carbon, which allowed them to determine how light exposure affects the amount of soil carbon converted to carbon dioxide emissions.

The team also used carbon dating to age the soil organic carbon and the carbon dioxide emitted from it to demonstrate this oxidation was happening to ancient permafrost, not just that which thaws annually. Soil that thaws annually would release a much smaller amount of carbon dioxide than what’s available in these ancient soils. The researchers determined that it was between 4000 and 6300 years old, showing that permafrost carbon is susceptible to oxidation to carbon dioxide.

Including these findings into climate change models means that there could be a release of 6% of the 100 billion metric tons of carbon currently stored in Arctic permafrost, the carbon equivalent of 29 million cars evaporating into the atmosphere. 

Featured image by: UBC Micrometeorology

The cracked, buckling road between Fairbanks and Fox, Alaska, wends its way past snowy forests where slender birches and black spruce trees protrude out of the ground at impossible angles, slanting and swaying as if the very earth were alive. Scientists call these ‘drunken forests’. The ground here consists of permafrost — soil, sediment, rock and ice that often remains at or below 0 degrees Celsius year-round. Permafrost covers approximately 22.8 million square kilometres in the Arctic, sub-Arctic and alpine regions — comprising nearly a quarter of the exposed land surface in the northern hemisphere.

In Alaska, 85% of the state lies within the permafrost zone, though discontinuous permafrost — areas with patchy permafrost presence — underlies much of the Fairbanks area. In Arctic regions, permafrost temperatures often dip down to -8 degrees C. But in Fairbanks, which lies roughly 321 kilometres south of the Arctic Circle, temperatures hover much closer to the freezing point, causing the permafrost to sporadically thaw out. This freeze-thaw action has long posed challenges for natural and human systems, intoxicating forests, breaking pavement, sinking houses, and even sometimes draining lakes sitting atop it.

But as climate change heats up the planet, with the Arctic warming at twice the rate of the rest of the globe, things are about to get a whole lot worse.

Why is permafrost melting bad?

Scientists began seriously worrying about climate change impacts on permafrost about 15 years ago, but not only because of degraded infrastructure. The world’s permafrost serves as a massive carbon reservoir, storing nearly twice the amount of carbon currently found in the atmosphere. An estimated 1 400 gigatons of carbon — made up of decomposed plants and animals which once inhabited the Earth — can be found embedded in permafrost.

By comparison, our atmosphere presently contains just 850 gigatons of carbon. As the planet warms and permafrost thaws, some of that locked-up carbon will be released into the atmosphere. The trillion-dollar question is how much and how fast?

You might also like: Scientists Underestimating Greenland Ice Sheet Melt- Study

Permafrost Gains International Scientific Attention

In 2011, Merritt Turetsky, the director of the Institute of Arctic and Alpine Research at the University of Colorado Boulder, helped found the Permafrost Carbon Network, connecting scientists studying permafrost across the globe, from Alaska to Canada to Siberia. Before that, much of the research on changes in the Arctic had centered on declining sea ice extent — not on land impacts.

“There wasn’t a lot of info out there. We had initial estimates of permafrost carbon loss that were based on back-of-envelope calculations,” says Turetsky.”

But those rough estimates were massive: “They showed that permafrost carbon release over a short order of time could be really disruptive and carried a lot of risk.” By connecting scientists and synthesising collected data, the network hoped to figure out how much carbon loss the world should expect.

Nearly a decade later, scientists have a much better handle on when, where and how thawing permafrost could impact the planet. “I think the scientific understanding is maturing and we’re seeing the evidence of that,” says Turetsky.

That’s crucial because the United Nation’s Intergovernmental Panel on Climate Change (IPCC) only recently started including permafrost thaw into its long-term projections. If we intend to limit warming to 2 degrees C, as stipulated in the 2015 Paris Climate Agreement, we’ll need to cut emissions even sooner than IPCC models currently predict to account for the carbon released by thawing permafrost.

Until recently, scientists assumed global permafrost wouldn’t lose more than 10% of its carbon, and that this would occur over a drawn-out timescale. But when they pooled observations from more than 100 Arctic field sites in the Permafrost Carbon Network, they found that the permafrost likely released an average of 1.662 trillion kilograms (1.832 billion tons)  of carbon each winter from 2003 to 2017 — double that of past estimates. On Alaska’s North Slope, permafrost temperatures have increased by 11 degrees F in just 30 years. In turn, the amount of CO2 released from the region in early winter has increased by 73% since 1975.

In a 2015 study, scientists found that for every one degree C rise in Earth’s average temperature, permafrost may release the equivalent of 4 to 6 years-worth of oil, coal and natural gas emissions. If fossil fuel use isn’t restrained, they said, permafrost could soon be as big a source of greenhouse gas emissions as China, the world’s second largest economic powerhouse.

The Risk of Abrupt Thaw

Though the IPCC is considering carbon emissions due to gradual permafrost thaw in its Sixth Assessment Report, due out in 2022, it won’t take abrupt thaw and subsequent greenhouse gas release into consideration.

Abrupt thaw, the large-scale surface subsidence of land, occurs in zones rich with subsurface ice and manifests as thermokarst, thaw slumps producing gullies, scar wetlands and thermokarst lakes. As temperatures rise, ice wedges or lenses can melt rapidly, destabilising soil and sediment above in a way akin to suddenly removing a support beam in a house, resulting in structural collapse.

Unlike gradual thaw which affects mere centimetres of permafrost and occurs over the time scale of decades, abrupt thaw can impact meters of permafrost in just months or years. This can shock the surrounding landscape into releasing even more carbon than if it had thawed at a leisurely pace.

In a paper published in February in Nature Geoscience, Turetsky and her co-authors found that, while abrupt thaw will likely occur in less than 20% of the world’s permafrost zone, it could affect half of all permafrost carbon through rapid erosion, collapsing ground and landslides. Despite influencing only a small portion of the Arctic, abrupt thaw emissions could have the same climate feedback effect as gradual thaw emissions would over the entire permafrost zone.

These abrupt releases could trigger a positive feedback loop whereby the permafrost’s greenhouse gas emissions would further warm the atmosphere, which would then thaw more permafrost and release more carbon. Turetsky says that without accounting for abrupt thaws, we’re underestimating the impact of permafrost carbon releases by 50 percent.

The Methane Conundrum

“The climate consequences are as high as gradual thaw because abrupt thaw is releasing a lot more of its carbon as methane,” Turetsky explains.

Though permafrost serves as a carbon sink, when that carbon is released into the atmosphere it can come out as either carbon dioxide (C02) or methane (CH4), depending on whether the carbon stores were subject to aerobic or anaerobic respiration. The danger here: methane is far more potent as a greenhouse gas than CO2, trapping up to 30 times more atmospheric solar radiation.

“If you look at just the magnitude of carbon, abrupt thaw only releases about 40 percent of the carbon relative to gradual thaw. But that carbon comes out as a lot of methane and it has bigger climate consequences,” Turetsky says.

“It’s both worrisome and reassuring at the exact time,” she adds. “What we now know is that abrupt thaw doesn’t affect a huge area of the Arctic” — that’s the good news — “but it does carry a punch. It affects the deepest and most carbon rich soils which are found in areas prone to abrupt thaw.”

In their 2019 paper, “The Polar Regions in a 2 Degree C Warmer World,” the authors lay out several emission scenarios that span releases between a modest increase of 10 teragrams of extra methane per year, to more than 50 teragrams through 2080 assuming a 2 degrees C increase in global temperature.

“Although increases in methane emissions in excess of 50 Tg represent extreme scenarios, these projections do not consider possible abrupt changes or accelerating trends. Given the potential for decomposition of large stocks of organic soil carbon, such changes could be an important factor in the future,” the authors write.

Over the next decade, researchers will be trying to model the potential methane releases from Arctic permafrost more precisely — those estimates will help policymakers determine just how short a time we have in which to act before our climate crisis morphs into a climate catastrophe.

The news isn’t all bleak: another study published in Science Advances in February used paleoclimate research to argue that though permafrost does have the potential to emit large quantities of methane, it’s “unlikely the gas released from those stores will reach the atmosphere.” Using ice cores from Antarctica, scientists examined air composition dating back 8 000 to 15 000 years, Earth’s last major deglaciation period. They found that methane emissions from ancient carbon reservoirs were small during this time, meaning the likelihood of old carbon reservoirs in the Arctic destabilising and emitting large amounts of methane in the present day is pretty low.

Winter Woes

But that doesn’t mean things are anywhere close to stable up North.

Since the late 19th Century, the Earth as a whole has warmed by about 0.8 degrees C. But the Arctic has warmed 2 to 3 degrees C. And scientists expect the region to warm an additional 2 degrees C above the 1981-2005 baseline over the next 25 to 50 years, if fossil fuel emissions aren’t curbed. That could cause big problems, not just in the Arctic summer, but in the dead of winter as well.

Last October, a study published in Nature Climate Change found that winter CO2 loss from the world’s permafrost regions could increase by 41 percent if greenhouse gas emissions aren’t reduced.

Scientists have long known that Arctic temperatures have been accelerating carbon emissions in winter time, but they were unsure of the exact winter carbon balance. Come spring and summer, the world’s permafrost continues to act as a carbon reservoir, locking up decaying organic material.  But these new results “indicate that winter CO2 loss may already be offsetting growing season carbon uptake,” says Sue Natali, director of the Arctic Program at Woods Hole Research Center and a member of the Permafrost Carbon Network.

Natali and her team synthesised field observations of CO2 emissions to estimate that the permafrost region is losing 1.7 million metric tons of carbon during the winter season that runs from October through April. By comparison, this landscape only takes up around 1 million metric tons per year. As the Arctic warms, permafrost CO2 release could increase by another 17% under a moderate global emissions reductions scenario, and would increase by 41% under a business-as-usual emissions scenario.

“The Arctic has been a [carbon] sink for a very, very long time,” says Natali. But, “we’re now changing how this system is functioning.” Researchers have long suspected that the Arctic could one day switch over to become a carbon source; Natali stresses that her team’s findings indicate this is already happening. “The ambition to stay below 2 degrees C of warming needs to be ramped up. And it needs to be ramped up sooner than later,” she says.

Featured image by: NPS Climate Change Response

This article was originally published on Mongabay, written by Gloria Dickie, and is republished here as part of an editorial partnership with Earth.Org.

Scientists from the Tomsk Polytechnic University in Russia recently recorded the highest-ever flares of methane emissions- up to nine times the average global atmospheric concentration- in the air over the East Siberian Arctic Shelf (ESAS).  

The average surface temperature of the earth has increased by about 0.9°C since the late 19th century, driven in part by man-made emissions of greenhouse gases, including carbon dioxide and methane. 

Why does methane trap more heat than carbon dioxide?

Although methane accounts for less than a quarter (16%) of global greenhouse gas emissions, it is roughly 30 times more potent than carbon dioxide in terms of absorbing heat and contributes 25% of man-made global warming as of 2013.

Permafrost systems are carbon-rich soils that remain completely frozen for at least two years straight. 17% of the Earth’s exposed land surface is underlain by permafrost. The thermal state of these systems is sensitive to changing climatic conditions and in particular to rising air temperatures. Studies have found that the Arctic permafrost will thaw due to rising temperatures and once thawed, soil microbes convert the organic carbon in the permafrost soil into greenhouse gases such as carbon dioxide and methane. This process could amplify global climate change. 

In October, scientists from the Tomsk Polytechnic University in Russia recorded the highest-ever amounts of methane in the air over the East Siberian Arctic Shelf (ESAS) during a 40-day research voyage led by chief scientist Igor Semiletov. 

The methane emissions they observed were up to nine times greater than the average global atmospheric concentration. “Nobody has detected these concentrations,” Semiletov said.

The scientists surveyed 60 sites across the ESAS known to have had methane emissions from underwater permafrost in the past. Each emission site varies in size, ranging from 100 square metres to a square kilometre. The water at these sites looks as though it’s boiling as methane bubbles to the surface. Researchers collected samples of the air above the bubbling columns of methane to determine the amount being released into the Arctic Ocean. 

During previous expeditions, the team had recorded methane concentrations of 3-5 parts per million at these sites. On this trip however, they recorded methane concentrations of up to 16 parts per million, well above the average global atmospheric concentration of 1.7 parts per million. 

“The methane emissions, which look like torches or flares, are all increasing,” Semiletov said.

Their discovery does not come as a surprise. In 2010, Professor Semiletov and his colleague Natalia Shakhova made waves with their paper, which showed that methane trapped beneath the underwater permafrost of the ESAS was leaking into the Arctic Ocean. 

Specifically, they found that in this area, more than 80% and 50% of bottom and surface waters respectively were supersaturated with methane, comparable to methane emissions found in the entire world’s oceans. 

The scientists attribute the sub-sea thawing to changes in thermal interactions in the ocean, which could be intensified by global warming. These interactions include the release of geothermal heat derived within the sub-surface of the earth, as well as air-sea heat fluxes, which transfer heat from the atmosphere to the ocean. 

Professor Shakhova warns that the release of only a small fraction of the methane held in the ESAS could trigger further abrupt climate warming via positive feedback mechanisms; methane released from thawing permafrost traps heat in the atmosphere, which in turn accelerates thawing. 

“The very shallow water column and weakening permafrost could lead to the doubling of methane in the atmosphere in a matter of decades,” she said in a statement.

Moving forward, Professor Semiletov calls for a consolidated effort to monitor methane emissions across the Arctic Ocean in a bid to mitigate its effects on global warming. “It’s crucially important to study the change in size of the seeps…we need to think about how to combine our efforts to study this, because it affects everyone,” he says.  

This is the first of two parts in an Earth.Org investigation of methane emissions in the polar regions. See December 23rd‘s article, ‘What Satellite Imagery Tells Us About Methane Emissions in Greenland’.  

Featured image by: Brocken Inaglory 

Subscribe to our newsletter

Hand-picked stories once a fortnight. We promise, no spam!

Instagram @earthorg Follow Us