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The continuing trends for the Arctic
NOAA’s 2018 Arctic Report Card points to rising temperatures, declining ice and new drivers of uncertain environmental change Alan Bailey Petroleum News
In its annual Arctic Report Card for 2018, the National Oceanic and Atmospheric Administration has documented the impacts of the continuing multi-year warming of the Arctic region. That warming is having environmental impacts, some of which are predictable, while some are unexpected - new emerging threats rapidly demonstrate the level of uncertainty over future environmental change, the report says.
Rising temperatures In 2018 Arctic surface air temperatures continued along an upwards trend at approximately twice the rate of what is observed elsewhere in the world. Those air temperatures were the second highest on record since 1900, second only to the record high temperatures recorded in 2016. Air temperatures in the past five years have exceeded all previous records. Apparently, there is no consensus view on why the Arctic is warming so much more quickly than other parts of the world, although several theories have been proposed, including the effect of the loss of summer sea ice on heat absorption, changes in cloudiness, and changes in levels of pollution.
The report says that atmospheric warming in the Arctic is causing the jet stream, the high-altitude global flow of air, to become sluggish and wavy, a phenomenon believed to be associated with abnormal weather in the Arctic and elsewhere, including severe winter storms in the eastern United States and severely cold weather last March in Europe.
The continuing warming of the atmosphere, an indicator of general climate change, has been notably impacting the Arctic region, the report says. Terrestrial snow cover is declining; the Greenland ice sheet and lake ice are melting; the ice melt is increasing Arctic river flows; and Arctic vegetation is greening and expanding. Although the amount of vegetation available for animal grazing has increased, the populations of caribou and wild reindeer living on the Arctic tundra have declined by nearly 50 percent over the last two decades, the report says.
Loss of sea ice In response to the warming of the ocean, Arctic sea ice is becoming thinner and younger, and is covering a smaller area than in the past, the report says. The winter maximum sea ice extent in 2018 was the second lowest recorded since satellite observations began in 1979. The minimum sea ice extent in September tied with 2010 as the sixth lowest extent on record, with the 12 lowest extents measured from satellite observations occurring in the last 12 years. And the disappearance of much of the thick, multi-year ice pack renders the ice more susceptible to summer melting and to unpredictable movement.
There also appears to be a long-term decline in land-fast ice, the ice that is anchored to the coast, the report says. This form of ice is critically important as a buffer, protecting the coast and coastal communities from erosion caused by winter storms. Land-fast ice is also extremely important as a platform for travel and hunting for Arctic communities.
The Bering Sea The report particularly comments on the shortage of winter ice on the Bering Sea, one of the more notable features of the 2017-18 sea ice season. Apparently a persistent southerly circulation brought relatively warm surface water and air north into the region, pushing any sea ice that formed north. The low ice cover in the winter and spring then allowed the absorption of more solar energy into the seawater. The lack of sea ice triggered a 500 percent increase in the productivity of marine algae - increased concentrations of algal toxins were measured in the tissues of various marine creatures, including Arctic clams, seals, walrus and whales, the report says.
Microplastics The relatively high concentration of microplastics in marine waters of the Arctic is also becoming a significant environmental concern - concentrations of these pollutants, formed from the breakdown of various plastic materials, have been found to be higher in the Arctic than in any other ocean basin around the world. Concentrations are particularly high in the Atlantic sector of the Arctic, probably as a consequence of the transportation of marine debris by ocean circulation. The plastic pollutants pose a threat to birds and other marine life that may ingest them, the report says.
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