Research News
A scientist stands in front of an ice-rich outcrop in the coastal area of Herschel Island, Yukon Territory, Canada. These ice-rich areas in permafrost country are rapidly eroded by coastal swell. Photo: Michael Fritz/AWI
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Arctic Coasts Pulling Back
The coastline in Arctic permafrost regions reacts to climate change with increased erosion. On average, it recedes by half a metre per year. This entails major changes for the Arctic coastal ecosystems and the population living there. The assessment results from the work of a pool of more than thirty scientists from ten countries, among them researchers from the Alfred Wegener Institute for Polar and Marine Research, a member of the Helmholtz Association, and from the Helmholtz Centre Geesthacht. In a joint effort, more than 100,000 kilometres, that is, a quarter of all Arctic coasts was examined. The changes in the Laptev Sea, the East Siberian Sea and the Beaufort Sea are particularly dramatic, with coastal erosion rates of in part more than eight metres per year. Since around a third of global coastlines are located in the Arctic permafrost region, the coastal erosion can affect huge areas in future. In general, Arctic coasts react more sensitively to global warming than the coastlines in more temperate latitudes. So far, they were protected from the eroding force of waves by huge expanses of sea ice. Because of the continuous reduction of sea ice, this protection is endangered and one has to reckon with spiralling alterations in conditions that remained stable for millennia. Two thirds of Arctic coastlines do not consist of rock but of frozen soft substrate (permafrost). It is those coasts in particular that are affected by erosion. Traditionally, Arctic areas may feature only small numbers of inhabitants. However, as is the case nearly all over the world, the northernmost coasts too are important lifelines for economic and social activities. Increasing demand for global energy resources as well as a growing tourism industry and increased transport of goods additionally intensify the human impact on coastal regions in the Arctic. As erosion progresses, the ecological conditions for wildlife such as the large reindeer herds of the North or the far spread inshore fresh water lakes change dramatically.
