Summarising recent research on Arctic sea ice
"If the Arctic really is the 'canary in the coal mine' for
climate change impacts" writes
BBC correspondent Richard Black in a new blog post, "…the signs
of sickness appear to be stronger and more certain than
before".
It's a great piece -
read it here.
The US National Oceanographic and Atmospheric Association's one line summary
of what's happening in the Arctic is
Return to previous Arctic conditions is
unlikely
Record temperatures across Canadian Arctic and Greenland, a
reduced summer sea ice cover, record snow cover decreases and links
to some Northern Hemisphere weather support this conclusion
Black's article acts as a useful summary of some of the recent
research into how the Arctic is changing, so we've listed it
here:
1. Icecap more resistant to warming than
feared
A paper in Nature last week showed that some melting glaciers
flow slower at higher temperatures, meaning that the icecap may be
more resistant to warming than previously feared - although the
researchers are keen to emphasise that this does not put the
Greenland ice sheet out of danger.
2. Melting icecaps mean more solar heat absorbed by
planet
Sea ice and snow are responsible for reflecting some of the
sunlight beaming down to the planet back to space - so melting ice
in the Arctic means more heat is absorbed. Researchers from the
University of Michigan have
calculated that this affect means that 10-20% more solar heat
is now being absorbed in the area than 30 years ago.
3. Warmer seas putting Arctic under
pressure
Ice is affected by higher temperatures in the air above and the
sea below. Using the marine sediment record, a team from the
University of Mainz has deduced that the temperature of Atlantic
water entering the Arctic ocean is higher
than its been for 2,000 years (
Climate Progress calls the temperature reconstruction from this
paper "one heck of a hockey stick").
4. Four summers in a row of record lows
At a briefing on the
coming season's work by the Catlin Arctic Survey, one of the
researchers pointed out that although summer melt records haven't
been set since 2007, we have just had four summers in
succession where the ice has shrunk back further than at any other
time since 1979.
5. Accelerating decrease in sea ice volume
The University of Washington's Polar Science Center has
calculated that a steady decrease in ice volume in the Arctic over
the last couple of decades has accelerated in the last few years,
as shown by the PIOMAS model:
Black concludes that in some areas, "science inevitably has to
play catch-up" to the rapid change that's happening.
A month ago a "negative phase" of the Arctic Oscillation brought
snow to western Europe and left parts of the Arctic unseasonably
warm - a phenomenon which has been linked to
loss of Arctic sea ice.
What this means for long-term weather patterns, we don't yet
know. However, Black estimates:
Already, a fair proportion - I won't
claim to know the exact figure, but I'd estimate it's over 90% - of
Arctic researchers believe that for the region as a whole, the
canary is already toppling off its perch.