Climate change: Thawing permafrost: When the coasts slide into the sea

Let’s remember: a third of all coastlines in the world are in the Arctic. They consist of ice-rich soil that is frozen to great depths, but is increasingly thawing and releasing greenhouse gases due to rising temperatures. However, it is not yet known exactly what consequences this will have for the climate and the oceans, nor what consequences the local people can expect. The coasts are, so to speak, the litmus strip for the effects of climate change.

The European Union has made more than eleven million euros available so that the effects of climate change on the Arctic coast can be researched. The project »Nunataryuk«, which means “from land to sea” in the language of the Inuvialut people living in Canada, was planned for five years. It had to be extended by one year due to the corona pandemic. It was finally completed in December 2023.

27 research institutions were involved in the Nunataryuk project. It was coordinated by the Alfred Wegener Institute for Polar and Marine Research (AWI), in particular its Permafrost Section in Potsdam. Primus inter Pares was the geomorphologist and permafrost researcher Hugues Lantuit. The fact that the Arctic coast loses about half a meter per year to the sea was considered the global average ten years ago, he says. »But there are places with much higher losses. For example, Stokes Point in northwest Canada. There the annual erosion rate in a particularly vulnerable area was two meters between 1996 and 2007, now we are at 7.6 meters per year.

And Stokes Point is a place with a radar station and a runway that’s getting shorter because of coastal erosion. Such examples can be found almost everywhere, for example on the Siberian Laptev Sea, in Alaska or on Spitsbergen. The reasons are obvious: As the average annual temperature increases, the sea ice that protects the coasts is retreating. This extends the summer season, the waves hit the coast longer and higher, the sea water warms up, and the temperatures of the permafrost on land also increase. The fact that coastal erosion is accelerating so quickly surprised researchers, says Lantuit. »Imagine if a stretch of coast on the Baltic or North Sea were to retreat five meters every year!«

As part of the Nunataryuk project, the Potsdam permafrost researchers modeled future coastal erosion up to the year 2100, based on data since 1900 and current developments. There is an optimistic scenario and a less favorable calculation in the event that humanity does nothing and everything continues as before. The scary version predicts a tripling of coastal erosion. In ten years global erosion would be thirty meters per year, in a hundred years it would be 300 meters. However, there are already local “hotspots” that reach such rates. There is still no reliable extrapolation for how many square kilometers of land mass this will result in.

Erosion endangers infrastructure

Hugues Lantuit’s working group examined all of these processes intensively on Herschel Island in northwestern Canada and in surrounding communities. The scientists often talk to the residents because that was the second component of erosion research: What dangers do the local people see? Which processes may have been overlooked by researchers or not taken seriously enough? What can be done to protect the infrastructure? That is why social scientists, economists and engineers also took part in “Nunataryuk”. Anthropologists from the University of Vienna in particular asked the residents about their findings and sensitivities. The results were incorporated into corresponding recommendations.

How existential the threat can be is shown by the large coastal settlement of Tuktoyaktuk on the Beaufort Sea, which had to be partially protected by solid concrete. Nevertheless, some houses were destroyed; you can see the empty spaces. Or there are storm surges due to the erosion of the coast that flood the entire town. Buildings tip over, are moved, pipes break.

The fact that Lantuit works primarily in these regions came about more or less by chance. The Frenchman, who grew up in Claye-Souilly, studied in Canada. Working at the AWI’s Potsdam branch, he wrote his doctoral thesis. The plan was to go to Siberia, but the well-known Russian bureaucracy refused entry. Call Canada. He was welcome there. Permafrost research in the area around the Mackenzie Delta became a mainstay of the Potsdam colleagues. Other colleagues are concentrating on Siberia, starting from the Bykowski station.

People sometimes ask why the EU releases such horrendous funds for permafrost research. In addition, the logistics for the expeditions are paid for by the AWI – ultimately all tax money. Do these expenses make sense given the investment shortage here? Absolutely. On the one hand, we know that all consequences of global warming, wherever they occur, have global effects and therefore also influence our lives in mid-latitudes. In addition, Hugues Lantuit sees a political connection. The dynamics of competition between systems in the 1960s to 1980s set the course for German polar research. The GDR entered Antarctica with extensive measurement programs. The Federal Republic responded with a delay with its strong presence in the north and south.

Research as a means of diplomacy

“Nowadays, polar research is also an instrument of soft diplomacy,” says Lantuit. The Arctic still has open political connections. There is the Arctic Council of the riparian states, which, however, does not make any binding decisions; these are reserved for the respective parliaments. But non-Arctic countries have some influence on its recommendations if they contribute significant scientific achievements. Germany has observer status in the Council and has been able to position itself quite well in the interests of the environment and the well-being of the population thanks to its precise, strictly fact-based research. The scientists’ findings and recommendations are introduced into the Arctic Council’s deliberations via the Foreign Office.

Using the example of coastal erosion, Lantuit makes it clear that these inputs require meticulous detailed work. The permafrost on land contains many organic compounds that have been stored for thousands of years. When it thaws, carbon dioxide and methane escape into the atmosphere and further drive global warming; that is known. If coastal areas break off, the soil ends up in the sea as sediment. The common opinion was: Everything stays there more or less unresponsive or is transported further. The geoscientists have now taken samples and measured how much CO. over the period of the ice-free summer season₂ is released. The result was striking: If permafrost gets into seawater, up to three times as much carbon dioxide is probably released as in the air.

“We are careful with generalizations because it is a laboratory experiment,” says Lantuit. »But this process was something new even for specialists. The introduced microbes and those that are already present in the water convert the carbon compounds immediately. Marine sediment can also be a source of greenhouse gases. On the other hand, the increased carbon content contributes to the acidification of the oceans. In the Arctic, the pH value is close to the limit at which living creatures can no longer build their calcareous skeletons and shells or the carbonate in the protective shells dissolves.

Thawing soils release pollutants

The Alfred Wegener Institute has been awarded the contract for a new EU-funded project. It focuses on the release of pollutants through the erosion of permafrost and its consequences for the health of the population. If the ground softens, industrial facilities can collapse. Previously frozen landfills are thawing and pollutants are released into the environment, water and the food chain. For example, mercury in the meat of beluga whales – the pigs of Canadian and Greenlandic cuisine, so to speak. Because of the mercury, Inuit women’s cancer rates are higher than elsewhere. It’s about identifying the legacy of the industry. According to an initial study, there are around 15,000 contaminated areas that could pose a greater risk in the future.

Hugues Lantuit will lead the project again. “We have to explore material flows and assess the dangers they cause – a difficult and costly environmental problem, because interest in economic activities will increase,” says Lantuit. And quotes, very pragmatically, Günter Grass: “A wide field.”