Thawing Arctic peatlands risk unlocking huge amounts of carbon
The Artic landscape is changing at an unprecedented pace: in Sweden, Alaska and elsewhere entire towns and villages, houses half sunken into the ground, risk being moved to more stable ground, as the permafrost they had been built on shifts and melts. In the Canadian north, suitable houses have become so rare that apartment prices have skyrocketed, triggering a housing crisis. All around the Arctic, homes lay abandoned, the damage too severe. Roads and other vital infrastructure are at risk, too.
Scientists have been warning us for quite some time now that a warmer planet could lead to the thawing of permafrost and the vegetable matter—peat—locked up inside it. Sinking homes are only the visible consequence of this phenomenon. Large-scale melting is expected to release huge amounts of CO2, which will in turn lead to more heating, with devastating consequences on the climate… and our everyday lives.
A recent study predicts that there’s a one in 20 chance of a 2-metre sea level rise if we do nothing.
“To avoid such a destructive scenario, it is critical that the world’s permafrost and its peatlands stay frozen and retain their carbon deposits,” says UN Environment peatlands expert Dianna Kopansky.
It’s estimated that the northern hemisphere’s frozen soils and peatlands hold about 1,700 billion tonnes of carbon—four times more than humans have emitted since the industrial revolution, and twice as much as is currently in the atmosphere. “Globally, permafrost temperatures have continued to rise in recent decades,” says UN Environment’s Frontiers report.
A recent expedition to the Canadian Arctic found that permafrost in outposts there is thawing 70 years earlier than predicted—a sign that the global climate crisis is accelerating faster than scientists had feared. The way in which permafrost peatlands respond to a warming climate and their collective role in global climate heating are not straightforward, as the interaction of permafrost, ecosystems and climate is extremely complex.
The northern circumpolar region holds almost half of the world’s soil organic carbon, largely in the form of permanently frozen peat. Arctic and subarctic peatlands exist within the permafrost zones of Canada, Denmark’s Greenland, Finland, Norway, Russia, Sweden and the United States.
Peatlands are characterized by a thick layer of dead plant remains, or peat. The water-saturated, oxygen-free and permafrost conditions prevent peat from full decay and allow it to accumulate over thousands of years. The intricate relationships between peat, vegetation, water and ice maintain the delicate balance of permafrost peatlands.
Indigenous peoples who have been living in Arctic regions for thousands of years have a deep physical and spiritual relationship with nature and know the importance of permafrost peatlands.
“If peatlands become sick and stop doing their job of storing huge amounts of carbon and regulating local climates, there are deep repercussions for my people,” says Candice Pedersen, an Inuk from Iaqluit, the capital of the Canadian territory of Nunavut. “We depend on them for our health and well-being.”
Hans Joosten, of the Greifswald Mire Centre and Secretary-General of the International Mire Conservation Group, who has studied peatlands around the world, explains the critical role of permafrost peatlands. “In summer, they prevent the heat from reaching the frozen permafrost underneath and during winter, they allow the cold to infiltrate the soil. More action to keep them functioning is critical if we are ever to keep the global temperature rise below 2°C,” he says.
Human activity
Climate breakdown is not the only factor directly influencing the changes in permafrost peatlands. Any disturbance to the surface soil can lead to permafrost degradation, including natural processes such as forest or tundra fires, and human activity, such as industrial and urban infrastructure development as well as mining, tourism and agriculture.
The removal of trees and shrubs leads to more solar heat input, permafrost collapse and wetter conditions. Open water accumulates summer heat and acts as a heat source in winter, affecting the distribution of permafrost.
In Russia, 15 per cent of the tundra has been destroyed by transport activities, resulting in permafrost thawing, erosion, subsidence and thermokarst development (marshy hollows and small hummocks formed as ice-rich permafrost thaws). About 45 per cent of the oil and natural gas production fields in the Russian Arctic are in the most ecologically sensitive areas, often in peatlands, including the Pechora region, Polar Urals and north-west and central Siberia.
“The near inevitability of accelerating impacts reinforces the urgent need for local and regional adaptation strategies targeting these carbon-dense northern ecosystems,” says Kopansky.
“Keeping peatlands healthy and doing their job will require good decision-making and the prudent management of permafrost peatlands. These will be key aspects to limiting greenhouse-gas emissions, reducing human and ecological vulnerabilities, and to building longer-term climate resilience to those most vulnerable.”
A Global Peatlands Initiative side event, “Permafrost and Peatlands—An Emerging Frontier in the defence against Climate Change”, was held on 22 June at the Global Landscapes Forum in Bonn, Germany. To read more about it click here.
For further information, please contact Dianna Kopansky.