The end of the Arctic as we know it?

A new report released at the International Conference on Arctic Science in the United States this week shows that profound changes are under way in the Arctic. Driven by increasing levels of atmospheric greenhouse gases and a warming Arctic Ocean, these changes are so dramatic, and so rapid, that they are creating a new Arctic climate.

The Arctic Monitoring and Assessment Program (AMAP), one of the Arctic Council’s six working groups, used the conference to launch its second Snow, Ice and Permafrost in the Arctic (SWIPA) report. The document assesses the current state of knowledge on the Arctic cryosphere (the portion of the earth’s surface that is seasonally or perennially frozen), the past, present and future trends and their implications. The assessment points to some major, and worrying, changes in the region.

For a variety of reasons, the Arctic has been warming more than twice as fast as the rest of the world for the past 50 years and that’s having dramatic effects on the Arctic cryosphere. This rapid warming is reducing the extent of older, multi-year sea ice to 4 million km2 from around 7.5 million km2 in 1979. It is also shrinking glaciers, reducing snow cover, and thawing permafrost.

Ten years ago, GRID-Arendal’s Global Outlook for Ice and Snow estimated that the Arctic Ocean would be free of ice in summer by 2100 or earlier. The SWIPA report now lowers this time horizon to the late 2030s. As if to bolster the report, this March the US National Snow and Ice Data Centre announced that the record low for winter sea ice maximum had been broken for the third year in a row. The sea ice that remains is increasingly thinner and younger, hastening the melt.

The report says the Greenlandic ice sheet will also drastically diminish and many of the small glaciers elsewhere in the Arctic will disappear. Changes on the cryosphere will have wide-ranging impacts on the Arctic environment, its inhabitants –and to parts of the world far from the region.

This expression is becoming increasingly meaningful as scientific research brings to light the connections between the Arctic and the rest of the planet.

The Arctic is generally seen as the Northern Hemisphere’s “cooling system” and the SWIPA explains that changes there may even have repercussions on South East Asia’s monsoon system. An illustration of this interconnectedness came out last month, when Chinese researchers highlighted the climatic repercussions of Arctic cryosphere changes, linking extreme pollution events in China to the diminution of Arctic sea ice and the increase in snowfall in Siberia.

The report also says increased river discharge due to ice sheet, glacier and snow melt, as well as the disappearance of sea ice, will also increase the amount of freshwater in the Arctic Ocean, potentially triggering changes in the oceanic circulation in the Northern Hemisphere. Changes in this circulation are also likely to affect the weather conditions in more southern areas.

Beyond climatic effects, the melting Greenlandic ice sheet and other Arctic glaciers are contributing to one third of the yearly global sea-level rise (or just over 1 millimeter per year), with an estimated total contribution of 25cm between 2006 and 2100, if increases in greenhouse gases continue at the current rate. Open water in the Arctic thus contributes to coastal erosion and other impacts on low-lying lands elsewhere in the world.

In these kinds of assessment, it’s usual to try to find a silver lining in the dark clouds. However, in the SWIPA there are way more cons than pros. The benefits linked to the opening of new sea routes, or the access to natural resources such as fish and oil and gas – the burning of which use would further increase global greenhouse gas concentrations – do not balance the cumulative costs of Arctic change which the report estimates at USD 7-90 trillion between 2010 and 2100.

The report not only confirms some alarming trends. It also suggests that a threshold has been crossed and that the Arctic climate is now shifting towards a new warmer, wetter and more variable state. Climate models used in the assessment show that reducing greenhouse gas emissions accordingly to the Paris Agreement’s provisions could slow some trends and stop the temperatures at 5-9°C above the 1986-2005 average in winter over the Arctic Ocean by the midcentury. This means that proper actions taken now to reduce global emissions will only result in a stabilization, at higher temperatures, in about three decades. The Arctic of 2100 will be substantially different from that of today.