By far, the largest fraction of the Arctic coastline consists of thawing permafrost (Box 8.1). Arctic permafrost coasts represent 34 per cent of all coasts on Earth. Coastal erosion rates have increased in recent years with values ranging around 1 metres /year. Erosion rates are highest along the Alaskan and Siberian coastlines, with maxima as high as
Box 8.1: Livelihood impacts in the Arctic 8
Reindeer (caribou) herds are an important part of Arctic ecosystems and integral to the livelihoods of indigenous peoples in Alaska, Arctic Canada, Scandinavia and the Russian Federation. Reindeer-herding communities depend on access to seasonal pastures. The seasonality and extent of pastures is changing as a result of climate change, impacting these pastoral communities.
Mining and resource extraction are also important in the Arctic. Changing Arctic conditions have made the construction and operation of the winter ice roads that supply mining outposts problematic. A warming climate has delayed freeze-up in the autumn (fall) and produced an earlier spring melt as well as thinner ice during the winter. This has led to shorter winter-road seasons. As the Arctic climate continues to warm, co-management institutions will find themselves increasingly dealing with trade-offs between sustainable development and sociocultural and ecological integrity of Arctic lands and livelihoods.
25 metre/year (Figure 8.17, Figure 8.18) (Günther et al. 2013; Overduin et al. 2014; Fritz, Vonk and Lantuit 2017). Therefore, increasing fluxes of organic carbon are released into the shelf seas. In some locations (Alaska), villages have had to be relocated further inland.
Figure 8.17: Coastal erosion rates at selected sites in the Arctic