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Thawing permafrost:  Is it a ticking timebomb?

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Permafrost covers about a quarter of the landmass in the Northern Hemisphere.  It stores vast quantities of organic carbon in the form of dead plant matter.  As long as it stays frozen, it is no threat to the climate.  But as it thaws, microorganisms start breaking down that plant matter and large amounts of carbon are released into the atmosphere in the form of carbon dioxide and methane.

This process has often been described as a ticking timebomb for the climate.  The theory is that once global warming reaches a certain level, the process will become self-amplifying setting off a catastrophic amount of warming.  If that level was reached, it would be a tipping point in the changing climate.

An international research team from the Alfred Wegener Institute in Germany has extensively researched this hypothesis.  Their conclusion is that within the permafrost, there are multiple geological, hydrological, and physical processes that are self-amplifying and, in some cases, irreversible.  However, these processes act only locally or regionally.  There is no evidence that some particular threshold in global warming could affect all permafrost and accelerate its thawing on a global level.

This research does not mean that Arctic permafrost is nothing to worry about.  In fact, there are ways in which it is more worrisome.  Because the permafrost is very heterogenous – meaning it is very different in different places – there will be numerous small, local tipping points that will be exceeded at different times and at different levels of warming.  All of this will proceed in step with global warming, contributing to the overall worsening situation.  There is no warming level below which permafrost thawing is not a problem.

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Thawing permafrost: Not a climate tipping element, but nevertheless far-reaching impacts

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenland is greening

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Despite their names, Iceland is very green, and Greenland is very icy.  But in Greenland, that is changing.  Temperatures in the world’s largest island are rising twice as fast as they are in the rest of the world and, as a result, the icy rocky landscape is turning increasingly green.

Satellite records reveal that over the last three decades Greenland has lost 11,000 square miles of ice, which is an area about the size of Massachusetts.  As the ice melts off, tundra and shrublands takes its place.  The ice melt moves sediment and silt and eventually wetlands and fenlands are formed.

Between the late 1980s and the late 2010s, the areas of Greenland covered by vegetation have more than doubled.  The new green areas cover roughly 33,000 square miles, which is an area the size of Maine.

Greenland’s dramatic changes are the result of the warming climate, but in turn, those changes are accelerating climate change.  Land covered with dark green vegetation absorbs more energy from the sun thereby warming the air whereas ice-covered landscapes reflect much of the sun’s energy back into space.  In addition, the rapidly expanding wetlands are a significant source of methane, which traps even more heat in the atmosphere.

Greenland is a poster child for the effects of climate change.  Its glaciers and icecaps are shrinking, glacier-fed lakes are expanding, permafrost lakes are draining, and rivers are transporting vast amounts of sediment and widening.  All of this is going on as its vegetation cover and species diversity is expanding.

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In Icy Greenland, Area Covered by Vegetation Has More Than Doubled in Size

Photo, posted September 20, 2019, courtesy of Amanda via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Shrinking Glaciers And Methane | Earth Wise

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The Arctic region is warming much faster than the rest of the planet.  In fact, according to a study published last year in the journal Nature, the Arctic has been warming nearly four times faster than the rest of the globe during the last 43 years.  This rapid warming is leading to substantial reductions in sea ice, thawing of permafrost, shifts in wildlife populations, and changes in ocean circulation patterns, among other changes. 

According to new research recently published in the journal Nature Geoscience, shrinking glaciers in the warming Arctic are exposing bubbling groundwater springs, which could provide an underestimated source of methane, a potent greenhouse gas.  Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere.

The study, which was led by researchers from the University of Cambridge and the University Centre in Svalbard, Norway, found large sources of methane gas leaking from groundwater springs unveiled by melting glaciers. 

As glaciers retreat in the Norwegian archipelago of Svalbard and leave behind newly exposed land, groundwater beneath the Earth seeps upward and forms springs. In 122 out of the 123 springs studied, the research team found that the water was highly concentrated with dissolved methane.  When the spring water reaches the surface, the excess methane can escape to the atmosphere. 

Researchers are concerned that additional methane emissions released by the Arctic thaw could dramatically increase human-induced global warming.  If this phenomenon in the Svalbard archipelago is found to be more widespread across the Arctic — where temperatures are quickly rising and glaciers melting — the methane emissions could have global implications. 

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The Arctic has warmed nearly four times faster than the globe since 1979

Shrinking Arctic glaciers are unearthing a new source of methane

Photo, posted October 22, 2022, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Vanishing Arctic Lakes | Earth Wise

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In recent decades, the warming in the Arctic has been much faster than in the rest of the world.  The phenomenon is known as Arctic amplification.  A study by the Finnish Meteorological Institute published in August in Communications Earth & Environment determined that during the past 43 years, the Arctic has been warming nearly four times faster than the rest of the globe.  The result of this amplified warming has been that glaciers are collapsing, wildlife is struggling, and habitats continue to disappear at a record pace.

Research published by the University of Florida has identified a new threat associated with Arctic amplification: lakes in the Arctic are drying up.

Over the past 20 years, many Arctic lakes have shrunk or dried up completely across the entire pan-Arctic region, which spans the northern parts of Canada, Russia, Greenland, Scandinavia, and Alaska.

Arctic lakes are essential elements of the Arctic ecosystem and for the indigenous communities that live in the region.  They provide a critical source of fresh water for those communities and local industries. 

The rapid decline of Arctic lakes is unexpected.  Earlier predictions were that climate change would first actually expand lakes in the region as ground ice melted.  Lakes drying out was not expected until much later in this century or even in the 22nd century.  Instead, it appears that thawing permafrost may drain lakes and overwhelm the expansion effect caused by melting ice.  The theory is that thawing permafrost decreases lake area by creating drainage channels and increasing soil erosion.

The finding suggest that permafrost thawing is occurring faster than anticipated, which presents many additional problems.

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As the climate crisis intensifies, lakes across the Arctic are vanishing

Photo, posted June 20, 2014, courtesy of Bob Wick / Bureau of Land Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Methane From Thawing Permafrost | Earth Wise

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The Arctic permafrost contains a massive amount of carbon in the form of frozen soil, which contains remnants of plants and animals that died millennia ago.  Estimates are that there is 2 ½ times as much carbon trapped in this Arctic soil than there is in total in the atmosphere today.

As the Arctic warms, the permafrost is starting to thaw.  Once that happens, microbes begin to consume the previously frozen organic matter trapped in the soil.  As part of this process, the microbes produce large amounts of methane, which is an extremely potent greenhouse gas.   Thus, there continues to be great concern that wide-scale thawing of the permafrost would result in massive amounts of methane being released into the atmosphere.

A recent study in northern Sweden revealed a glimmer of hope.  The study gauged methane emissions from a swath of permafrost that thawed in the 1980s and another that thawed 10 or 15 years later. 

In the first area, as ice melted underground, water on the surface sank down into the soil.  As the surface dried out, new plants emerged that helped to keep methane emissions buried underground.

Grasses found in wet areas have straw-like structures that convey oxygen to their roots.  The straws also allow methane in the soil to escape into the atmosphere.  As the areas dry out, other plants lacking the straws can sometimes replace the grasses.  When methane can’t escape, soil bacteria break it down into carbon dioxide.

The result is that the permafrost releases only a tenth of the methane as expected.  The hope is that changes in plant cover driven by climate change may limit methane emissions from thawing permafrost.

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Thawing Permafrost In Sweden Releases Less Methane Than Feared, Study Finds

Photo, posted July 7, 2014, courtesy of NPS Climate Change Response via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dangers Of Thawing Permafrost | Earth Wise

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The thawing of the permafrost in the Arctic is a major concern from the standpoint of the potential release of enormous amounts of carbon dioxide trapped in it.  There are nearly 2,000 billion tons of carbon there, which is as much as humanity releases into the atmosphere in 50 years.  But greenhouse gases are not the only danger posed by permafrost thawing.  There are also microbes, unknown viruses, and chemicals that could be very dangerous.

More than 100 diverse microorganisms in Siberia’s deep permafrost have been found to be antibiotic resistant.  The deep permafrost is one of the few environments on Earth that have not been exposed to modern antibiotics.  As the permafrost thaws, its bacteria could mix with meltwater and create new antibiotic-resistant strains.

By-products of fossil fuels – introduced into permafrost environments since the beginning of the industrial revolution – are present.  Metal deposits including arsenic, mercury, and nickel, have been mined for decades and have contaminated large areas.

Now-banned pollutants and chemicals – including DDT – came to the Arctic through the atmosphere and over time have become trapped in the permafrost.

There is now ongoing research further characterizing the microbes frozen in permafrost and providing more precise measurement of emissions hotspots in permafrost regions.  Scientists are increasingly turning to integrated Earth observations from the ground, the air, and space.

There are models that predict the gradual release of emissions from permafrost over the next century.  Other models say it could happen within just a few years.  The worst-case scenario would be utterly catastrophic but none of the scenarios portend anything good.

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Thawing Permafrost Could Leach Microbes, Chemicals Into Environment

Photo, posted February 9, 2017, courtesy of Benjamin Jones/USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Permafrost Thaw | Earth Wise

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We’ve talked about permafrost before.  It is the frozen soil, rock, or sediment piled up in the Arctic that has been there at least for two years but, for the most part, for millennia or even over a million years.  Permafrost holds the carbon-filled remains of vegetation and animals that froze before they could start decomposing.   Estimates are that there are nearly 2,000 billion tons of carbon trapped in Arctic permafrost.  To put that in perspective, annual global carbon emissions are less than 40 billion tons.

Keeping all that carbon frozen plays a critical role in preventing the planet from rapidly heating. The ongoing warming of the Arctic is causing the subsurface ground to thaw and release long-held carbon to the atmosphere.

Scientists from Europe and the US are working together to better track permafrost carbon dynamics.  They are trying to understand the mechanisms that lead to abrupt thaws in the permafrost that have taken place in some locations.  These rapid thawing events are not well understood.  Researchers are also studying the effects of the increasingly frequent wildfires in the Arctic on the permafrost.

Researchers are using satellites to better understand the effects climate change is having on the Arctic environment and how these changes, in turn, are adding to the climate crisis.  Permafrost cannot be directly observed from space, so that its presence has to be inferred from measurements like land-surface temperature and soil moisture readings.  Terrestrial observations are also necessary for understanding how greenhouse gases – both CO2 and methane – are being emitted from the Arctic.

Thawing permafrost is a ticking timebomb for the environment that demands the growing attention of the scientific community.

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Permafrost thaw: it’s complicated

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Beavers Are Flooding The Warming Arctic | Earth Wise

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The accelerating warming in the Arctic has transformed the region into a warmer, wetter, and more diverse environment.  Warming temperatures have encouraged the increasing growth of vegetation, particularly shrubs that provide beavers with bark to eat and branches to build with.  Warming temperatures also mean that lakes and streams freeze solid for shorter periods of time or not at all, allowing beavers to pursue their construction projects for longer periods during the year.

Prior to the mid-1970s, residents of the Alaskan Arctic encountered few beaver ponds.  In 2018, researchers using satellite imagery mapped 12,000 beaver ponds in Alaskan tundra.

Beavers are causing major changes in the streams and floodplains that many small Alaskan villages depend upon for food, water, and navigation.  As the rodents transform lowland tundra ecosystems, they are eliminating food sources, deteriorating water quality, and making it difficult to navigate waterways.

The migration of beavers across the Arctic landscape is largely a result of climate change.  But it is also becoming one of the factors amplifying climate change.  Scientists are trying to figure out the degree of permafrost thawing that beaver dam-and-den building is causing and how fast these defrosted organic soils will degrade and release trapped carbon and methane.

Beaver dams alter the hydrology of streams by slowing the flow, storing and spreading water to create wetlands, raising the water table, and lowering the oxygen content of the water. 

Climate-driven changes in species distributions affect human well-being as entire ecosystems continue to change.  Shifts in animal habitat stimulated by climate change could have profound consequences across the globe.

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Beavers Are Flooding the Warming Alaskan Arctic, Threatening Fish, Water and Indigenous Traditions

Photo, posted June 12, 2018, courtesy of Peter Pearsall/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Arctic Communities And Permafrost Thaw | Earth Wise

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Permafrost is frozen soil, rock or sediment that can be as much as a few thousand feet thick.  To qualify as permafrost , the material has to have been at or below the freezing point of water for two or more years.  Most of it is located in high latitudes in the Arctic and Antarctic regions.   Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost contains enormous amounts of carbon in the form of frozen soil that includes remnants of plants and animals, in some cases that have been there for more than 20,000 years.

The Arctic region has been warming faster than any place else on earth and thawing permafrost is already unleashing methane and carbon dioxide to the atmosphere, adding to the global temperature rise.

Apart from the impact on the global climate, thawing permafrost is making the ground unstable and is causing serious problems for local communities.

Recent research using satellite observations provides an overview of the Arctic to identify communities and infrastructure that will be at risk over the next 30 years.

Using high-resolution data from the Copernicus Sentinel satellite missions along with ground-based data going back to 1997, researchers modeled the permafrost ground temperature trends and extrapolated them out to 2050.  The results were that 55% of the infrastructure currently located on permafrost and within 60 miles of the Arctic coastline – infrastructure on which many communities rely – is likely to be affected.

Most human activity in the Arctic takes place along permafrost coasts.  Permafrost thaw is exposing these coasts to rapid change that threatens biodiversity and puts pressure on communities.

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Satellites pinpoint communities at risk of permafrost thaw

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alaska Is Getting Wetter | Earth Wise

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Siberia has been in the news for record-setting heat waves and wildfires, but it is not the only northern region experiencing unusual weather.   Alaska, apart from setting its own warm weather records, is experiencing the rainiest five years in its century-long meteorological record.

Extreme weather in the Arctic is being driven by an aspect of climate change called Arctic amplification, which leads to temperatures rising faster than the global average.  The physical basis of Arctic amplification is well understood, but its effects over time are much less predictable.

The past five years included two summers with average precipitation, one that was a little drier than usual, and two of the wettest summers on record.    Researchers have taken measurements of how far below the surface permafrost has thawed by the end of summer over a wide range of Alaskan environments.

About 85% of Alaska sits upon permafrost and the increasing rainfall over the past five years is leading to a deeper thaw of permafrost across the state.  The wettest summer on record was 2014 and permafrost didn’t freeze back to previous levels even when the next couple of summers were relatively drier.

The study demonstrated how different types of land cover govern relationships between summer rainfall and permafrost thaw.  As Alaska becomes warmer and wetter, the vegetation cover is projected to change, and the increasing occurrence of wildfires will disturb larger areas of the landscape.  These conditions are likely to lead to a feedback loop driving more and more permafrost thawing.

Fundamental changes to Alaskan ecosystems are occurring on an unprecedented timescale – not gradually over decades or lifetimes, but over mere months or years.

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Alaska is getting wetter. That’s bad news for permafrost and the climate.

Photo, posted June 10, 2011, courtesy of Peter Rintels via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Beavers And The Warming Arctic | Earth Wise

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Beavers have a remarkable ability to transform landscapes.  Using their sharp teeth, they fell trees and shrubs and build dams, which cause small valleys to fill with water and form new lakes.  Some of these lakes measure five or ten acres in size, or even more.  And beavers are very efficient builders; they often build their dams at precisely those points where can they have the greatest effect with the least effort.

Scientists studying beaver activity in the Arctic regions of Alaska have found that the changing climate is leading to a substantial increase in beaver populations and their effect on the landscape.

In 2018, researchers found that the beavers living in a 7,000 square-mile area in northwest Alaska had created 56 new lakes in just five years.  Thanks to rising temperatures, more and more habitats offer the shrubs that beavers need for food and building material.  In addition, the lakes, which used to freeze solid, now offer beaver-friendlier conditions.  Also, beavers are not hunted as intensively as in the past.

The scientists were surprised that beavers have seized the opportunity so intensively.  There is basically an exponential growth in beaver dams.  This is actually a worrisome situation.  Forming all these new lakes degrades ice-rich permafrost in the area.  In the Kotzebue region of Alaska, the overall water area has increased by more than 8% over the past 17 years, and roughly two-thirds of that is due to beavers.

The degradation of the Arctic’s permafrost is a dangerous situation and it appears that anyone who wants to predict its future has to keep the activity of beavers in mind.

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Beavers gnawing away at the permafrost

Photo, posted June 23, 2018, courtesy of Becky Matsubara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Carbon Dioxide From Thawing Permafrost | Earth Wise

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The Arctic is warming much faster than the rest of the planet.  Stories about the loss of polar ice and hundred-degree temperatures in Siberia have become commonplace.  One of the most troubling aspects of the warming Arctic is the thawing of permafrost.  Permafrost is ground that remains frozen for at least two years; some of it has been frozen for tens or hundreds or even thousands of years.  Found under a layer of soil, permafrost is composed of rock, soil, sediments, and varying amounts of ice.  It stores the carbon-based remains of plants and animals that froze before they could decompose.  Permafrost covers almost a quarter of North America, but it is starting to thaw.

Scientists estimate that there are more than 16,000 billion tons of carbon locked away in Arctic permafrost, which is almost double the amount of carbon that is currently in the atmosphere.  Climate models predict that the warming of the Arctic could lead to 5 to 15% of that carbon to be emitted as carbon dioxide by the year 2,100, which would be enough to raise global temperatures by 0.3 to 0.4 degrees Celsius.

New research has increased this estimate because it includes a key pathway for CO2 to enter the atmosphere that earlier models ignored.   When carbon from thawing permafrost escapes into Arctic lakes and rivers, it is oxidized by ultraviolet and visible light and it then escapes into the atmosphere as CO2.  This process is known as photomineralization and is estimated to raise permafrost-related CO2 emissions by 14%.

Recent studies project that with every 1-degree Celsius increase in temperature, 1.5 million square miles of permafrost could be lost through thawing.

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Climate Models Underestimate CO2 Emissions from Permafrost by 14 Percent, Study Finds

Photo, posted July 7, 2014, courtesy of NPS Climate Change via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Record Siberian Heat | Earth Wise

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Siberia has been experiencing unprecedented high temperatures in recent months.  May was the hottest May on record and temperatures in Siberia have stayed well above average for the past year.

On June 20, temperatures in the small Siberian town of Verkhoyansk hit 100.4 degrees Fahrenheit, which is a record-high temperature in one of the fastest-warming places in the world.  Average high temperatures in June reach 68 degrees.  Verkhoyansk sits on the Yana River in the Arctic Circle and, during the winter, is one of the world’s coldest towns.  In 1892, its temperature dropped to -90 degrees Fahrenheit.  And now there is hundred-degree heat above the Arctic Circle.

Siberia tends to experience large temperature swings month-to-month and year-to year.  But it is very unusual for temperatures to stay well over average over an extended period of time as they have for the past year.  According to climate scientists, the kind of temperature swings seen recently would only happen once in 100,000 years if it were not for climate change.

Siberia has seen raging wildfires and structural damage from thawing permafrost as its temperatures have stayed warmer than normal.  The prolonged Siberian heatwave is an alarming situation.

The Arctic is warming twice as fast as the rest of the Earth because of a process known as Arctic amplification.  The acceleration of the Arctic ice melt leads to a seasonal snow cover that isn’t as white.  It therefore absorbs more sunlight, which then leads to more warming.

The amplified warming of the Arctic with its increased melting of ice leads to higher sea levels, and not just in the Arctic Ocean.  With less Arctic ice to reflect sunlight, the world’s oceans continue to warm. 

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Temperatures in an Arctic Siberian town hit 100 degrees, a new high

Photo, posted December 7, 2014, courtesy of Olga Dudenko via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Hidden Source Of Arctic Carbon | Earth Wise

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Researchers from the University of Texas at Austin, the U.S. Fish and Wildlife Service, and Florida State University have published a paper presenting evidence of significant and previously undetected concentrations and fluxes of dissolved organic matter entering Arctic coastal waters.  The source of the organic matter is groundwater flow atop the frozen permafrost.  The groundwater moves from land to sea unseen, but the new research reveals that it carries significant concentrations of carbon and other nutrients to Arctic coastal food webs.

Globally, groundwater is important for delivering carbon and other nutrients to oceans, but in the Arctic, where much water is trapped in the permafrost, its role was thought to be minimal.  But the new research reveals that groundwater may be contributing an amount of dissolved organic matter to the Alaskan Beaufort Sea that is comparable to what comes from neighboring rivers during the summer.

The researchers found that shallow groundwater flows beneath the surface and picks up new, young organic carbon and nitrogen, but it also mixes with layers of deeper soils and thawing permafrost, picking up and transporting century-to-millennia old organic carbon and nitrogen.  This material is unique because it is directly transported to the ocean without seeing or being photodegraded by sunlight and may be valuable as a food source to bacteria and higher organisms that live in Arctic coastal waters.

The study concluded that the supply of leachable organic carbon from groundwater amounts to as much as 70% of the dissolved organic matter that enters the Beaufort Sea from rivers during the summer.  The role that groundwater inputs play in Arctic coastal ecosystems will be an area of active research for years to come.

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Hidden Source of Carbon Found at the Arctic Coast

Photo, posted June 14, 2015, courtesy of Eugen Marculesco via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving The Arctic Permafrost | Earth Wise

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Permafrost is frozen ground – a combination of soil, rock, sand, and ice – that remains at or below freezing for at least two consecutive years.  Approximately 25% of the land in the Northern Hemisphere meets this criterion, the majority of which can be found in northern Russia, Canada, Alaska, Iceland, and Scandinavia.

But as a result of the changing climate, these permafrost soils in the Arctic are beginning to thaw.  As they thaw, large quantities of greenhouse gases could be released, further accelerating climate change.  

A new study recently published in the journal Scientific Reports explores an unconventional countermeasure: resettling massive herds of large herbivores.  According to researchers from the University of Hamburg in Germany, herds of horses, bison, and reindeer could be used to significantly slow the loss of permafrost soils. 

During Arctic winters, the air temperature is often much colder than the permafrost.  Thick layers of snow can insulate the ground from the frigid air, keeping the permafrost warm (relatively speaking). But when the snow cover is scattered and compressed by the hooves of grazing animals, the insulating effect is reduced, which intensifies the freezing of the permafrost.

If climate change continues unchecked, the research team expects permafrost temperatures to rise 3.8-degrees Celsius.  This would result in half of the world’s permafrost thawing by the year 2100.  But in contrast, researchers found that the permafrost would only warm by 2.1 degrees Celsius with the resettled animals.  This 44% reduction in permafrost temperature would preserve 80% of the existing permafrost by 2100.

Natural manipulations of ecosystems could have tremendous results. 

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How horses can save the permafrost

Photo, posted July 17, 2012, courtesy of Kitty Terwolbeck via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Melting Permafrost | Earth Wise

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The Arctic is warming faster than any region on Earth and mostly we’ve been hearing about the rapid disappearance of Arctic sea ice.  But the land in the Arctic is also undergoing major changes, especially to the permafrost that has been there for millennia.

Permafrost occurs in areas where the temperature of the ground remains below freezing for two years or more.  About a quarter of the Northern Hemisphere’s landscape meets this criterion.  Most of the world’s permafrost is found in northern Russia, Canada, Alaska, Iceland, and Scandinavia.

Permafrost regions previously carpeted in cranberries, blueberries, shrubs, sedges, and lichen are now being transformed into nothing but mud, silt, and peat.  So-called regressive thaw slumps – essentially landslides – are creating large craters in the landscape.  (The Batagaika Crater in the Yana River Basin of Siberia is a kilometer long and 100 meters deep).

Apart from the violence being done to the Arctic landscape, the greatest concern is that the permafrost has locked in huge stores of greenhouse gases, including methane, carbon dioxide, and nitrous oxide.  It is estimated that the permafrost contains twice as much carbon as is currently contained in the atmosphere.  As the permafrost thaws, these gases will be released.  With them will be pathogens from bygone millennia whose impact cannot be predicted.  Climatologists estimate that 40% of the permafrost could be gone by the end of the century.

As the permafrost thaws, the region’s ecosystems are changing, making it increasingly difficult for subsistence indigenous people and Arctic animals to find food.  Landslides are causing stream flows to change, lakes to suddenly drain, seashores to collapse, and water chemistry to be altered.

The warming Arctic is about much more than disappearing sea ice.

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How Thawing Permafrost Is Beginning to Transform the Arctic

Photo, posted February 9, 2017, courtesy of the U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Arctic As A Carbon Source

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According to a new NASA-funded study, the Arctic may now be a source for carbon in the atmosphere rather than being the sink for it that is has been for tens of thousands of years.

The study, published in Nature Climate Change, warns that carbon dioxide loss from the world’s permafrost regions could increase by more than 40% over the next century if human-caused greenhouse gas emissions continue at their current pace.  Worse yet, carbon emitted from thawing permafrost has not even been included in most climate models.

Permafrost is the carbon-rich frozen soil and organic matter that covers nearly a quarter of Northern Hemisphere land area, mostly in Alaska, Canada, Siberia, and Greenland.  Permafrost holds more carbon than has ever been released by humans from fossil fuel burning, but it has been safely locked away by ice for tens of thousands of years.

As global temperatures rise, the permafrost is starting to thaw and release greenhouse gases into the atmosphere.

The recent findings indicate that the loss of carbon dioxide during the winter in the Arctic may already be offsetting carbon uptake during the growing season.  The researchers compiled on-the-ground observations of carbon dioxide emissions across many sites and combined these with remote sensing data and modeling.  They estimate that the permafrost region is now losing 1.7 billion metric tons of carbon during the winter season but taking up only 1 billion during the growing season.

The major concern is that as the Arctic continues to warm, more carbon will be released into the atmosphere from the permafrost region, which will further the warming.  Climate modeling teams across the globe are trying to incorporate these findings into their projections.

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Arctic Shifts to a Carbon Source due to Winter Soil Emissions

Photo, posted July 27, 2015, courtesy of Gary Bembridge via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Degraded Permafrost In The Arctic

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Permafrost is defined as rock or soil that has been at or below the freezing point of water for two or more years.  Most of it is located in high latitudes in and around the Arctic and Antarctic regions.   Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost can contain many different materials including bedrock, sediment, organic matter, water and ice.  Because of the presence of organic matter, permafrost is potentially the source of significant methane emissions if it thaws and the trapped biomass begins to rot.

A recent study looked at the results of 30 years of aerial surveys and extensive ground mapping of an area of Canada’s high Arctic polar desert known as the Eureka Sound Lowlands.  This area has an extremely cold climate and the permafrost there is over 1/3 of a mile thick.  It has long been assumed that this landscape was stable.

Research led by McGill University in Montreal has found that this is not the case.  The increases in summer air temperatures seen in recent years are initiating widespread changes in the landscape.

A particular landform known as a retrogressive thaw slump that forms when ice within permafrost melts and the land slips down is widely occurring in the area.  The absence of vegetation and layers of organic soil in these polar deserts make permafrost in the area particularly vulnerable to increases in summer air temperatures.

The research indicates that despite the cold polar desert conditions that characterize much of the high Arctic, the interaction between ice-rich permafrost systems and climate factors is complex and the links between global warming and permafrost degradation are not well understood.

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Widespread permafrost degradation seen in high Arctic terrain

Photo, posted August 11, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Defusing The Methane Time Bomb

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Permafrost is defined as soil that remains frozen for two or more consecutive years.  It is generally composed of rock, soil, sediments, and varying amounts of ice that binds it all together.  The permafrost of the Arctic represents one of the largest reservoirs of organic carbon in the world.  It covers vast regions of Siberia, northern Canada, Alaska and Greenland.

When permafrost thaws, microbes in the previously-frozen soil go to work digesting organic materials and release carbon dioxide and methane, both of which are greenhouse gases.  Methane is 25 times more effective in trapping heat in the atmosphere than carbon dioxide, so it represents the greater threat.  The massive amounts of methane that could be released by thawing permafrost have been described as a ticking time bomb threatening the world’s climate.  Unfortunately, the permafrost in the Arctic is already starting to thaw as a result of climate change.

A new study by researchers at the International Institute for Applied Systems Analysis looked into the prospects for neutralizing the threat posed by the release of methane from thawing permafrost.  They analyzed the relative contributions of potential methane emissions from the permafrost and existing ones from human activities.  Human-caused methane emissions from fossil fuel activities, waste dumps, and livestock constitute a major source of the gas.  

Their conclusion is that if we can greatly reduce human-generated methane release, the effects of uncontrolled Arctic methane emissions could be mitigated.   It is unclear whether we can do much to stave off the Arctic methane release at this point, but the release of methane from human activities is something we can do something about.  But the clock is ticking.

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Diffusing the methane bomb: We can still make a difference

Photo, posted August 14, 2011, courtesy of Flickr.

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