No signs of hope as Arctic melts
Warmer Arctic temperatures are the 'new normal,' report finds
(CNN)Arctic
temperatures are continuing to rise while sea ice declines, a new
report has found, with the region showing no sign of returning to its
"reliably frozen" state.
The
report, sponsored by the US National Oceanic and Atmospheric
Administration (NOAA), shows that in 2017 a warming trend in the Arctic
continued, resulting in higher surface and water temperatures and
melting sea ice.
Some 85 researchers from a dozen countries contributed to the Arctic Report Card, now in its 12th year.
"While
2017 saw fewer records shattered than in 2016, the Arctic shows no sign
of returning to the reliably frozen region it was decades ago. Arctic
temperatures continue to increase at double the rate of the global
temperature increase," a NOAA news release on the report said.
The report card indicates that this may be the "new normal" for the region.
Historical
data show the current observed rate of sea ice decline and warming
temperatures are higher than at any other time in at least the past
1,500 years and likely much longer.
"The
rapid and dramatic changes we continue to see in the Arctic present
major challenges and opportunities," said retired Navy Rear Adm. Timothy
Gallaudet, the acting NOAA administrator.
"This
year's Arctic Report Card is a powerful argument for why we need
long-term sustained Arctic observations to support the decisions that we
will need to make to improve the economic well-being for Arctic
communities, national security, environmental health and food security."
Major findings in the report include:
- Warmer air temperature, with the average annual air temperature over land for the year ending September 2017 the second-warmest since 1900. It was 2.9 degrees Fahrenheit (1.6 Celsius) above the average for the period of 1981 to 2010.
- Declining sea ice, with this year's maximum winter sea ice area, measured each March, the lowest ever observed. Sea ice is also getting thinner each year, with young ice covering a wider area.
- Above-average ocean temperature, with sea surface temperatures in August 2017 in the Barents and Chukchi seas up to 4 degrees Celsius warmer than average.
- Increased Arctic ocean plankton blooms, as the retreat of sea ice allows sunlight to reach the ocean and encourages more marine plant growth across the Arctic.
- A greener tundra, as plants get bigger and leafier, with shrubs and trees taking over grassland or tundra, satellite data shows. The biggest increases are occurring on the North Slope of Alaska, Canada's tundra and Siberia's Taimyr Peninsula.
According
to the report card, there was greater snow cover in Asia in spring 2017
but less in North America, with the extent of snow cover in the North
American Arctic below average for the 11th year of the past 12. It was
the first time that the Eurasian part of the Arctic had above-average
snow cover since 2005.
Scientists recorded below-average melting on Greenland's ice sheet in 2017 compared to the previous nine years, after an early melt slowed during a cooler summer.
However,
the ice sheet -- a major contributor to a rise in global sea levels --
continued to lose mass in 2017, as it has since measurements began in
2002.
The unprecedented rate of
change in the Arctic is disproportionately affecting the people of
northern communities, the report said, "further pressing the need to
prepare for and adapt to the new Arctic."
'Extraordinary' Arctic changes
Jeremy
Mathis, director of the Arctic Research Program for NOAA, told CNN in
October that he had witnessed an "extraordinary transition" in the
Arctic environment since 2003, during which time he has made 14 trips to
the region.
"When I started going
to the Arctic in 2003, it was very different environment that it is
today," he said. "Back in 2003, we were breaking ice everywhere we went,
from pretty much starting in the Bering Strait moving all the way up
into the study areas north of Alaska and into the central Arctic basin.
There was ice that was very thick and it was very extensive.
"This
year in 2017, during a 25-day cruise in the Arctic, we didn't see a
single piece of ice. We were sailing around on a coast guard icebreaker
in blue water that could have been anywhere in the world. And it
certainly didn't look like the Arctic."
The
Arctic environment has changed from one that was dominated by sea ice
"to one that is now largely ice-free during the summer months," Mathis
said. "And that transition in ice cover has had real impact on
everything from fishers to polar bears because everything in the
ecosystem is really built around that ice coverage."
The
fact that the Arctic is warming twice as fast as the rest of the planet
is down to a phenomenon known as Arctic amplification, Mathis said.
Put
simply, the Arctic is changing from a highly reflective surface to a
very dark surface, he said. This means that sunlight entering the
atmosphere that would normally be reflected back into space by sea ice
or snow and glaciers is instead being absorbed by dark surfaces like the
ocean, land and rock.
"The Arctic
acts like a refrigerator for the entire Earth," said Mathis. "So, it
doesn't matter where you live. You are going to feel the impacts of
Arctic change."
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