Profound changes are being observed in the Arctic. Over the past four decades, the far northern region has warmed almost four times faster than the global average. Since the beginning of industrialisation, average temperatures in some parts of the Arctic have risen by 5 degrees Celsius, according to the German Environment Agency. The reason for this accelerated change lies in specific feedback effects: this “Arctic amplification” is both the result and the driving force behind a series of interconnected processes. Permafrost soils are thawing and releasing gases such as carbon dioxide and methane, which affect the climate; as thawing progresses, coastlines crumble and collapse. More frequent droughts are leading to more large-scale forest fires, which also release climate-relevant gases. On land and at sea alike, both the biogeochemical and the ecological balance are being severely disrupted.
These changes are not confined to the Arctic itself. “The Arctic is a hub for numerous climatic processes of global importance,” explains geoscientist and climate physicist Thomas Stocker. The Arctic is the source of northern deep water, it acts through sea-ice cover as a “cooling system” far beyond the region itself, and with increasing warming it is a potential source of additional greenhouse gas emissions. Stocker emphasises: “What happens in the Arctic does not stay in the Arctic.”
The statement by the seven science academies paints a clear picture of the far-reaching consequences: the accelerated melting of the Greenland ice sheet will contribute to a faster rise in sea levels and thereby threaten low-lying coastal regions worldwide. Warming in the Arctic could also alter ocean currents, which would then redistribute ocean heat differently around the globe, with consequences for weather and regional climate patterns.
