Warmer Arctic is the 'new normal'

13/12/2017

Línea Verde

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A warming, rapidly changing Arctic is the "new normal" and shows no signs of returning to the reliably frozen region of the past.

This is according to the US National Oceanic and Atmospheric Administration's Arctic Report Card.

Director of the administration's Arctic Researcher Program, Dr Jeremy Mathis, said the region did a great service to the planet - acting as a refrigerator.

"We've now left that refrigerator door open," he added.

Dr Mathis was speaking at the annual American Geophysical Union meeting in New Orleans, where Noaa presented its annual summation of Arctic science.

This is the 12th report the administration has produced. And although it pointed to "a few anomalies" in a recent pattern of warming in the Arctic region, Dr Mathis said: "We can confirm, it will not stay in its reliably frozen state."

"The thing I took that had the most resonance for me was we're able to use some really long-term records to put the Arctic change into context - going back more than 1,500 years.

"What's really alarming for me is that we're seeing the Arctic is changing faster than at any rate in recorded history."

The speed of change, Dr Mathis added, was making it very hard for people to adapt.

"Villages are being washed away, particularly in the North American Arctic - creating some of the first climate refugees," he said.

"And pace of sea level rise is increasing because the Arctic is warming faster than we anticipated even a decade ago."

The 2017 Arctic headlines

  • Warmer air: Average annual air temperature over land was the second highest after 2016, with a temperature 1.6C above average.
  • Declining sea ice: The maximum winter sea-ice area, measured each March, was the lowest ever observed. Sea ice is also getting thinner each year.
  • Warmer ocean: Sea surface temperatures in August 2017 were 4C above the average in the Barents and Chukchi seas. Surface waters of the Chukchi Sea have warmed by more than half a degree C per decade since 1982.
  • Plankton blooms: Springtime melting and retreating sea ice allows sunlight to reach the upper layers of the ocean, meaning more of these microscopic marine plants can photosynthesise.
  • Greener tundra: Overall vegetation, including plants getting bigger and leafier and shrubs and trees taking over. Grassland or tundra, increased across the Arctic in 2015 and 2016, as measured by satellite.
  • Ups and downs for snow: For the 11th year in the past 12, snow cover in the North American Arctic was below average, with communities experiencing earlier snow melt. The Eurasian part of the Arctic saw above average snow cover extent in 2017 - the first time that has happened since 2005.
  • Less melt on Greenland Ice Sheet: Melting began early on the Greenland Ice Sheet in 2017, but slowed during a cooler summer, resulting in below-average melting when compared with the previous nine years. Overall, the Greenland Ice Sheet, a major contributor to sea-level rise, continued to lose mass this past year, as it has since 2002 when measurements began.

BBC News. Science & Environment. 2017 NOAA Arctic Report Card

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