Catching Glaciers in Action
No matter how complex the models or extensive the computer programs, gauging what is happening to Earth's climate and its natural systems needs boots on the ground, on the water, on the ice, and in the air. Glaciologist Gordon Hamilton of the University of Maine and physical oceanographer Fiammetta Straneo of the Woods Hole Oceanographic Institution are doing just that.
Working out of the small Greenland village of Tasiilaq, they have for several years undertaken a coordinated, two-pronged investigation of the water and glaciers of Sermilik Fjord. Hamilton and his team comb Helheim Glacier, installing and checking cameras and GPS units; Straneo and her team drop probes into the water in the fjord to measure its temperature.
As the two scientists explained to staffers at a gathering on Capitol Hill late last year, Hamilton has found that Helheim Glacier has surged in speed, from approximately 7,000 meters (roughly four miles) per year in 2003 to almost 12,000 meters (approximately seven miles) a year by 2005. Straneo, meanwhile, has discovered that, around the time Helheim and other east Greenland glaciers began surging, the water temperature increased along the island's east coast. Those water temperatures are now the warmest they have been in the last 50 years, and there is "increasing evidence that ocean warming is playing a role in accelerating Greenland's glaciers," Straneo says.
As the glaciers surge, they deposit greater amounts of ice into the ocean, not only causing Greenland's ice sheet to decrease in size more rapidly than anticipated, but also contributing to sea level rise. The increased pace of this ice loss, and the fact that previous models did not factor such a contribution from Greenland, has prompted Hamilton and other glaciologists to conclude that sea levels could conceivably rise by as much as 144 cm (57 inches) by 2100, rather than the 18-59 centimeters (7 to 23 inches) predicted by the Intergovernmental Panel on Climate Change.
To refine their measurements and improve their data, Hamilton, Straneo and other researchers need to return year after year – and working in the Arctic is never easy. Novel methods are helping, such as attaching sensor tags to narwhals as a means of measuring water temperature in Baffin Bay, off Greenland's west coast. But even planned expeditions have to deal with bad weather. Last year, I watched as Hamilton and team paced nervously, anxious that they would lose precious days of research because the helicopter they had chartered was stranded in the Faroe Islands.
An extensive article in Sunday's New York Times also mentioned the logistical difficulties of gathering data in Arctic environments: "Not only do [Straneo and Hamilton] remove the doors of helicopters and lean over icy fjords to get their readings, but they dodge huge icebergs in tiny boats and traipse over glaciers scarred by crevasses that could swallow large buildings," writes Justin Gillis.
However, as Gillis points out, while Straneo and Hamilton are able to conduct annual surveys thanks to National Science Foundation funding, there are still many questions that only continuous monitoring (not just yearly visits) and improved data-gathering technology might solve. Currently airplanes equipped with ice-penetrating radar are flight-by-flight mapping the topography of the land beneath glaciers, and only four icebreakers in the world are equipped with multi-beam technology to piece-by-piece put together a picture of the Arctic seafloor.
And although an Obama Administration proposal for greater funding for NASA to study Earth science has attracted bipartisan support, broader wrangling over the federal budget means those funds have not yet been allocated. NASA, NSF, other agencies, and independent researchers are filling in the gaps as best they can. But the danger, concludes Gillis, is clear:
Climate scientists note that while the science of studying ice may be progressing slowly, the world’s emissions of heat-trapping gases are not. They worry that the way things are going, extensive melting of land ice may become inevitable before political leaders find a way to limit the gases, and before scientists even realize such a point of no return has been passed.
Photograph by Kieran Mulvaney