Wednesday, 13 December 2017

NOAA releases Arctic Report Card

NOAA’s 2017 Arctic Report Card Shows Transition Toward Not-Normal Polar Environment Continues


The Arctic shows no sign of returning to the reliably frozen region of recent past decades.— NOAA

Reading this [Arctic Report Card], I feel physically sick. I feel so anxious. I’m not sure how many more years or months I’m going to be able to work daily on climate change. — Eric Holthaus

*****
12 December, 2017

During 2017, the Arctic experienced much warmer than normal winter and fall temperatures. Meanwhile, according to NOAA’s 2017 Arctic Report Card, somewhat cool late spring and early summer temperatures did little to abate a larger ongoing warming trend.
NOAA notes:
The average surface air temperature for the year ending September 2017 is the 2nd warmest since 1900; however, cooler spring and summer temperatures contributed to a rebound in snow cover in the Eurasian Arctic, slower summer sea ice loss, and below-average melt extent for the Greenland ice sheet.


(NOAA’s Arctic Report Card shows a Polar environment experiencing serious and harmful changes.)
This warming trend was evidenced by continued systemic long term sea ice losses with NOAA stating that sea ice cover has continued to thin even as older, thicker ice comprised only 21 percent of Arctic Ocean coverage compared to 45 percent during 1985.  NOAA noted very slow Chukchi and Barents sea ice re-freeze during fall of 2017 — which was a feature of much warmer than typical sea surface temperatures during late August. Temperatures which ranged up to 4 C above average for this time of year and that created a kind of heat barrier to typical fall ice cover expansion.

Sea ice is a primary indicator of Arctic health. But losses over recent decades have been quite precipitious as indicated by the graph below:
Sea Ice Coverage Loss
(Arctic sea ice loss since 1978 during September [red] and March [black]. Image source:NOAA.)

NOAA also found evidence of ongoing increases in ocean productivity in the far north — which tends to be triggered by increasing temperature and rising ocean carbon uptake (also a driver of acidification).
(Changes in Arctic ground temperature [20 meter depth] at varying locations shows widespread movement toward permafrost thaw. Image source: NOAA.)
Tundra greening trends also continued over broad regions:
Long-term trends (1982-2016) show greening on the North Slope of Alaska, the southern Canadian tundra, and in the central Siberian tundra; tundra browning is found in western Alaska (Yukon-Kuskokwim Delta), the higher-Arctic Canadian Archipelago, and western Siberian tundra.
Rapid warming of the Arctic, loss of sea ice, permafrost thaw, greening tundra, changes in ocean productivity and other factors are all starting to seriously impact the people of the Arctic. Coastal towns have been forced to move inland due to erosion and sea level rise. And a number of communities have lost access to key food sources due to sea ice loss or migration of local species away from warming regions. Subsidence has generated harmful impacts to infrastructure. 

Meanwhile, the increased incidence of Arctic wildfires presents a rising hazard to Northern Communities:
High latitude fire regimes appear to be responding rapidly to environmental changes associated with a warming climate; although highly variable, area burned has increased over the past several decades in much of Boreal North America. Most acreage burned in high latitude systems occurs during sporadic periods when lightning ignitions coincide with warm and dry weather that cures vegetation and elevates fire danger. Under a range of climate change scenarios, analyses using multiple approaches project significant increases (up to four-fold) in area burned in high latitude ecosystems by the end of the 21st century.

Taken together this is tough news — a technical report written in the lingo of science but that, in broad brush, describes evidence of a world fundamentally changed. For those of us with sensitive hearts, it’s a rough thing to write about:
Reading this, I feel physically sick. I feel so anxious. I'm not sure how many more years or months I'm going to be able to work daily on climate change. Today is one of those days.
6:20 AM - 13 Dec 2017

Overall, NOAA calls for increased efforts to adapt to climate change in the far north. In addition, the need for mitigating harms from climate change by speeding a transfer to renewable energy could help to preserve cryosystems and ecosystems that are now under increasingly severe threat.


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