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, “â?¦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:
Image - piomas-seaice-volume (note)
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.