Arctic permafrost is melting rapidly. It affects us all


Four years ago, Morris J. Alexie had to move out of the house his father built in Alaska in 1969 because it was sinking into the ground and water was starting to seep into his house.

“Bogs are appearing between houses, all over our community. There are currently seven houses that are occupied but very tilted and sinking into the ground as we speak,” Alexie said by phone from Nunapitchuk, a village of about 600 people. “Everywhere is bogged down. »

What was once grassy tundra is now riddled with water, he said. Their grounds are criss-crossed by 8-foot-wide boardwalks that the community uses to get from place to place. And even some of the walks started to sink.

“It’s like the peas of the tundra. We used to have regular weed throughout our community. Now it has turned into a swamp with constant water.

Thawing permafrost — the long-frozen layer of ground that has underpinned the arctic tundra and boreal forests of Alaska, Canada and Russia for millennia — is upending the lives of people like Alexie. It also dramatically transforms the polar landscape, which is now dotted with massive sinkholes, newly formed or drained lakes, collapsing seashores and fire damage.

It’s not just the 3.6 million people who live in polar regions and who have to worry about thawing permafrost.

Everyone does it – especially the leaders and the climate policy makers from nearly 200 countries now meeting in Egypt for COP 27, the annual UN climate summit.

The vast amount of carbon stored in the northernmost regions of our planet is an overlooked and underestimated factor in the climate crisis. The frozen ground contains about 1.7 trillion metric tons of carbon, or about 51 times the amount of carbon the world released as fossil fuel emissions in 2019, according to NASA. It may already emit as much greenhouse gas as Japan.

Thawing permafrost gets less attention than shrinking glaciers and ice caps, but scientists says that has to change – and fast.

“Permafrost is like the dirty cousin of ice caps. It is a buried phenomenon. Do not you see it. It is covered with vegetation and earth. said Merritt Turetsky, director of the Institute of Arctic and Alpine Research at the University of Colorado at Boulder. “But it’s over there. We know it’s there. And it has an equally important impact on the global climate.

This is particularly urgent because Russia’s invasion of Ukraine has ended much scientific cooperation, meaning a potential loss of access to key data and knowledge about the region.

Warmer summers – the Arctic is warming four times faster than the global average – have weakened and deepened the upper or active layer of permafrost, which thaws in summer and freezes in winter.

This thaw awakens soil microbes that feed on organic matter, allowing methane and carbon dioxide to escape from the soil and into the atmosphere. This can also open pathways for methane to rise from reservoirs deep within the earth.

“Permafrost essentially served as an earth freezer for ancient biomass,” Turetsky said. “When these creatures and organisms died, their biomass became incorporated into these frozen layers of soil and then was preserved over time.”

As the permafrost thaws, often in complex and poorly understood ways, the lid of the freezer opens and scientists like Turetsky work harder to figure out how these changes will unfold.

w 1280

Permafrost is a particularly unpredictable wildcard in the climate crisis because it’s not yet clear whether carbon emissions from permafrost will be a relative drop in the bucket or a devastating addition. The latest estimates suggest that the magnitude of carbon emissions from permafrost by the end of this century could be equal equal to or greater than the current emissions of the main fossil fuel emitting countries.

“There is some scientific uncertainty about the size of this country. However, if we adopt a high emissions scenario, it could be as big or bigger than the United States,” said Brendan Rogers, associate scientist at the Woodwell Climate Research Center in Massachusetts.

He described the permafrost as a sleeping giant whose impact was not yet clear.

“We’re just talking about a huge amount of carbon. We don’t expect the whole thing to thaw…because part of it is very deep and would take hundreds or thousands of years,” Rogers said. “But even if a small fraction of that is admitted into the atmosphere, that’s a big deal.”

Projections of cumulative permafrost carbon emissions from 2022 to 2100 range from 99 gigatonnes to 550 gigatonnes. By comparison, the United States currently emits 368 gigatons of carbon, according to an article published in September in the journal Environmental Research Letters.

Smoke from a wildfire is visible behind a permafrost watchtower at the Scotty Creek Research Station in Canada's Northwest Territories in September.  The tower burned down in October due to unusual wildfire activity.

Not all of the climate change models that policymakers use to make their already bleak forecasts include projected emissions from permafrost. thaw, and those who do assume it will be gradual, Rogers said.

He and other scientists are concerned about the prevalence of abrupt or rapid thaw in permafrost regions, which has the power to shock the landscape by releasing much more carbon than with gradual downward warming alone.

The traditional view of permafrost thawing is that it is a process that slowly exposes layers, but “sudden thawing” exposes deeper layers of permafrost faster in several ways.

For example, Big Trail Lake in Alaska, a newly formed lake, spews bubbles of methane, a potent greenhouse gas, which comes from melting permafrost beneath the lake’s water. Methane can prevent these lakes from refreezing in winter, exposing deeper permafrost to warmer temperatures and degradation.

Bubbles of methane, a potent greenhouse gas, appear on the surface of Big Trail Lake in Alaska.

Rapid thawing of permafrost is also occurring following intense wildfires that swept through parts of Siberia in in recent years, Rogers said. Sometimes these flames smolder underground for months, long after the flames above ground have been extinguished, earning them the nickname zombie fires.

“The fires themselves will burn off some of the active layer (permafrost) by burning the ground and releasing greenhouse gases like carbon dioxide,” Rogers said. “But this ground that was burned was also insulating, keeping the permafrost cool in the summer. Once you get rid of it, you get much deeper active layers very quickly, which can lead to higher emissions in subsequent decades.

The sudden appearance of about 20 perfectly cylindrical craters in far northern Siberia over the past 10 years is also of great concern. Dozens of meters in diameter, they are thought to be caused by a buildup and explosion of methane – a previously unknown geological phenomenon that has surprised many permafrost scientists and may represent a new pathway for methane previously contained deep in the earth can escape.

“The Arctic is warming up so fast,” Rogers said, “and crazy things are happening.”

w 1280

A lack of monitoring and data on the behavior of permafrost, which covers 15% of the northern hemisphere’s exposed land surface, means scientists still have only a patchy and localized understanding of rapid thaw, how it contributes to global warming and affects people living in permafrost regions.

Rogers at the Woodwell Climate Research Center is part of a new $41 million initiative, funded by a group of billionaires and called the Audacious Project, to understand permafrost thaw. It aims to coordinate a pan-Arctic carbon monitoring network to fill some of the data gaps that have made it difficult to incorporate permafrost thaw emissions into climate goals.

The project’s first carbon flux tower, which tracks the flow of methane and carbon dioxide from the ground to the atmosphere, was installed this summer in Churchill, Manitoba. However, plans to install similar monitoring stations in Siberia are in disarray following Russia’s invasion of Ukraine.

“It’s always been more difficult to work in Russia than in other countries…Canada, for example,” Rogers said. “But this (the invasion), of course, made it exponentially more difficult.

Sebastian Dotterl, professor and a soil scientist at ETH Zurich, a Swiss university, who studies how warmer air and soil temperatures alter plant growth in the Arctic, was able to travel this summer to the Norwegian archipelago of Svalbard in the Arctic to collect soil and plant samples.

However, the field trip cost twice as much as originally planned because the group was prohibited from using any Russian-owned infrastructure, forcing the team to rent a tourist boat and reorganize. his route. But Dötterl said the more pressing problem is that he can no longer interact with his counterparts in Russian institutions.

“We are now dividing a fairly small community of scholars around the world into disconnected political groups, where our issues are global and should be connected,” he said.

Turetsky agreed, saying the war in Ukraine had been a “disaster for our scientific enterprise”.

“Russia and Siberia are huge, huge players. … Many projects funded by the European Union and the United States to work in Siberia to do any type of lateral knowledge sharing, they have all been cancelled.

“Are we going to stop trying? No of course not. And we can do a lot with existing data and with global remote sensing products. But it was a real setback for the community.

cnn en2fr2en

Back to top button