Climate change is occurring much faster than the IPCC models project. The Greenland ice sheet is a prime example. Robert Correll, chairman of the Arctic Climate Impact Assessment, said in Ilulissat recently:
We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at two metres an hour on a front 5km [3 miles] long and 1,500 metres deep. That means that this one glacier puts enough fresh water into the sea in one year to provide drinking water for a city the size of London for a year.
The glacier’s movement is accelerated as water flows down “moulins” (see picture) to the ice-bedrock interface at the bottom and acts as a lubricant for the entire glacier to slide and glide on. This “provides a mechanism for rapid, large-scale, dynamic responses of ice sheets to climate warming,” according to research led by NASA and MIT scientists [PDF]. Yet this factor has been given “little or no consideration in estimates of ice-sheet response to climate change.”
The models are missing the moulins — even though you can’t miss them in the real world. Correll said that flying over the glacier in the 1960s he saw no moulins, but now “there are hundreds of them.”
Just how fast can a glacier move? Correll “measured one surge at 5km in 90 minutes — an extraordinary event.”
The whole idea of “glacial change” happening too slowly to see will vanish in a world where glaciers are shrinking so fast that you can actually watch them retreat. Greenland’s glaciers are moving faster than America’s climate policy, which, I suppose, isn’t saying that much anymore.
This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.
