Permafrost thaw due to climate change to entail huge cost on Arctic infrastructure, studies warn

Thawing of the permafrost amid rising temperatures, much of it caused by human activity, will have a serious impact on infrastructure in the Arctic region and will cost billions of dollars to rectify, according to newly-released scientific papers.

In research published by the online journal Nature Reviews Earth and Environment on Jan 11, scientists warned that anthropogenic warming, or environmental change caused by man, will impact 69 percent of the residential, transportation and industrial infrastructure in permafrost regions by the middle of this century.

Scientists from around the world collaborated to produce six research papers examining the physical, biogeochemical and ecosystem changes related to permafrost thaw and the associated impacts.

Jan Hjort, a professor of physical geography at the University of Oulu, Finland, and one of the scientists who worked on the project, said the cost from permafrost degradation could amount to tens of billions of dollars.

Much of the Northern Hemisphere is covered by permafrost. It is estimated that 85 percent of Alaska is permafrost, or land that remains frozen for two or more years in a row, while 55 percent of Russia and Canada is also permafrost.

In one research paper titled "Impacts of permafrost degradation on infrastructure", scientists said in Russia the total cost of support and maintenance of road infrastructure owing to permafrost degradation from 2020 to 2050 is expected to reach approximately $7 billion for the existing network, with no additional development.

The authors note that there are some techniques to alleviate these impacts, such as air convection embankments (which use a porous stone layer to generate convection within embankments and improve heat extraction).

However, a better understanding of the regions at high risk is needed for mitigation methods to be effective, they said.

Hjort told China Daily in an email that anthropogenic warming is the key driver of "observed and projected climate change".

He said permafrost regions will see shorter snow periods and less cover.

"Permafrost will be warmer, and thaws will cover extensive areas. Biota (distribution of plants and animals) will change while the amount and distribution of Arctic species will decrease," he said.

Hjort said tree lines will slowly advance north while "shrubification" (expansion of shrubs) will spread across the Arctic, from the North Slope of Alaska to the isolated expanse of Siberian tundra.

He said some regions will get wetter while other areas become dryer.

"These are the impacts we know but (there) may well be others we don't even know about yet," he said.

Arctic permafrost regions store nearly 1.7 trillion metric tons of frozen and thawing carbon. Anthropogenic warming threatens to release an unknown quantity of this carbon into the atmosphere, influencing the climate in process.

The scientists warn that methane and carbon dioxide escaping from long-frozen soil could accelerate warming and overwhelm global efforts to cap the rise in Earth's temperature at liveable levels.

They say exposure of highly combustible organic matter no longer locked away by ice is also fuelling unprecedented wildfires, making permafrost a triple threat.

Blanketing a quarter of the Northern Hemisphere's land mass, permafrost contains twice the carbon currently in the atmosphere, and triple the amount emitted by human activity since 1850.

In another paper titled "The changing thermal state of permafrost", scientists noted that increases in permafrost temperature vary spatially owing to interactions between climate, vegetation, snow cover, organic-layer thickness and ground ice content. 

In warmer permafrost (temperatures close to 0 C), rates of warming are typically less than 0.3 C per decade, as seen in sub-Arctic regions. 

However, in colder permafrost (temperatures less than −2 C) as seen in the high-latitude Arctic, warming of up to about 1 C per decade is apparent. 

Sharon Smith, a permafrost research scientist working with the Geological Survey of Canada and one of the co-authors of the paper, told China Daily that a greater understanding of longer-term interactions between permafrost and the surrounding environment is needed to "reduce the uncertainty regarding the thermal state of permafrost and its future response".

"Permafrost and the ice within the frozen ground, influences the movement of water (including surface and subsurface water flow), ecosystems and the strength and behaviour of the ground," she said in an email. 

"Changes in permafrost conditions, its warming and thawing, can therefore have implications for hydrological processes, ecosystems and stability of the landscape such as ground settlement, slope instability, with subsequent impacts on northern lifestyles and infrastructure."

Smith said permafrost in alpine areas influences landscape stability, so warming and thawing can also have implications for infrastructure. 

"Analysis of records of permafrost temperature and active layer thickness indicate that permafrost is warming across the Arctic and in alpine areas," she said.

"Permafrost can also contain significant amounts of organic material that stores carbon in the frozen ground. This carbon can potentially be released as permafrost thaws, with impacts on the climate system."