The conclusions of the newly-released Copenhagen Diagnosis report - that climate change is proceeding more rapidly, and its effects are being felt more dramatically, than models had predicted - is not news to anyone who has been tracking the issue closely.
As I organized this past summer's research expedition on board the Greenpeace icebreaker Arctic Sunrise, the pitch I made was that the worst-case scenarios weren't bad enough, and that models were being outstripped by the realities on the ground and on the ice. Last week, two of the researchers from that expedition - Gordon Hamilton of the Climate Change Institute at the University of Maine, and Fiamma Straneo of Woods Hole Oceanographic Institution (pictured here talking with Mike McCracken, formerly with the Office of Global Change during the Clinton Administration) - shared some of their preliminary findings, and that same message.
Speaking to congressional staffers and other invited guests at the U.S. Capitol, Hamilton pointed out that Intergovernmental Panel on Climate Change (IPCC) estimates of global sea level rise were for between 18 and 59 centimeters by 2100, a figure that was almost entirely based on thermal expansion of the ocean, with a little bit of glacial melt and some melting of the Greenland Ice Sheet thrown in. But, said Hamilton, an emerging consensus among glaciologists is that that figure is more likely to be between 100 and 144 cm (up to 57 inches) of sea level rise (and some researchers say it could be higher still) - a figure based largely around a phenomenon not even included in the IPCC assessment.
The Greenland ice sheet is already losing as much as 300 billion tons of ice every year, says Hamilton, not just through melting but also the discharge of icebergs into the sea by Greenland's outlet glaciers. Glaciers calve icebergs all the time, of course, but the rate at which they are doing so has increased three-fold over the last few years, to the extent that Kangerdlugssuaq Glacier in East Greenland, for example, is now advancing at a rate of more than 14,000 meters a year - or, he says, "half a football field a day."
Straneo added that, around the time Greenland's glaciers began surging, researchers noticed an increase in water temperatures along the island's east coast. Those water temperatures are now the warmest they have been in 50 years of records, and, Straneo says, there is "increasing evidence that ocean warming is playing a role in accelerating Greenland's glaciers."
From onboard the Arctic Sunrise and during previous expeditions to the area, Straneo has detected warm water at the front of some outlet glaciers, which she believes is causing submarine melting. It's a process completely lacking from IPCC modeling, which is focused entirely on atmospheric warming of the ice.
So, if you've ever been of a mind to flip through an IPCC assessment report, and come away depressed about the state of things, remember this. Things aren't as bad as the IPCC may have you believe.
They're worse.
(First photo: Tim Aubry/Greenpeace. Second photo: Kieran Mulvaney)
NOTE: This blog has been edited to take account of an author error. The rate of movement of Kangerdlugssuaq Glacier (not Helheim, as originally written) is 14,000 meters per year, not 40,000.
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