Global environmental challenges
Greenland’s ice sheet melted at a record rate in 2010, and this could be a major contributor to sea level rise in coming decades.
The ice in Greenland melted so much last year that it formed rivers and lakes on top of the vast series of glaciers that covers much of the big Arctic island, with waterfalls flowing through cracks and holes toward the bottom of the ice sheet. Take a look at video from Marco Tedesco of City College of New York, who is leading a project to study what factors affect ice sheet melting. The photo at left shows a camp by the side of a stream flowing from a lake — all of it on top of the ice sheet.
“This past melt season was exceptional, with melting in some areas stretching up to 50 days longer than average,” Tedesco said in a statement. “Melting in 2010 started exceptionally early at the end of April and ended quite late in mid- September.”
Summer 2010 temperatures in Greenland were up to 5.4 degrees F (3 degrees C) above average, and there was reduced snowfall, Tedesco and his co-authors noted in an article in the current edition of Environmental Research Letters. Nuuk, Greenland’s capital, had the warmest spring and summer since records began there in 1873. Average summer temperatures vary widely, but in coastal areas hover around freezing.
A thaw of ice in the mountains of Norway is helping Lars Piloe and his team of archaeologists uncover a 1,500-year-old trove of equipment used by ancestors of the Vikings to hunt reindeer.
Their work as “ice patch archaeologists” points to one of a few positive side-effects of man-made climate change, widely blamed for shrinking glaciers worldwide.
As a view out of your home it’s hard to match — a constantly changing vista of icebergs just outside the British Antarctic Survey’s Rothera research station.
Every day the winds and tides on the Antarctic Peninsula shift them around — some break up abruptly with a loud splash while many simply slowly grind into ice cubes against the shore and disappear. I’ve tried to take a picture every day from the main balcony here (there’s a metal mast on the right hand side of each photo).
Welcome to the front lines of global warming in the United States – the Harding Ice Field in Alaska, the biggest icefield in the United States.
At the Exit Glacier north of Seward – the only glacier in the Kenai Fjords National Park reachable by foot – the giant cerulean blue ice sheet gives every sign of staying put.
But one only has to glance at the many signs along the roadway and footpath to the glacier’s edge to mark its retreat – it hit its peak size in 1815 and has been receding ever since. Signs along a footpath leading to the base of the glacier show just how far it has retreated.
The glacier lost about 10 feet from its front face over the summer of 2008.
Since the 1980s, land-based glaciers and ice caps like this one in Alaska have contributed the most to sea level rise than any other source within their category, which includes other land-based glaciers like Tanzania’s Mount Kilimanjaro and the Chacaltaya Glacier near La Paz, Bolivia, said Brenda Ekwurzel, a climate expert with the Union of Concerned Scientists.
Unlike the ice cover around the North Pole or giant floating ice sheets, land-based ice contributes directly to sea-level rises.
According to a 2007 report by the U.N.’s Intergovernmental Panel on Climate Change, glaciers and ice caps have the potential to raise global sea levels by between .15 meters and .37 meters.
That pales in comparison to the giant ice sheets in Greenland and Antarctica, which could raise sea levels by 63.9 meters if they fully melted.
At the Aialik Glacier in the Harding Icefield – reachable by boat or plane, the living nature of the ice was more evident.
On a visit to the glacier via tourboat on Aug. 15 on a trip hosted by the Knight Center for Environmental Journalism, several chunks of ice broke apart and crashed into Aialik Bay.
Throughout the visit, the ice cracked andgroaned, with a sound like thunder claps that punctuated the still air.
We hear a lot of grim news about how sea ice has been melting more than usual in recent summers in the Arctic, how glaciers from the Himalayas to the Andes are melting or how winter sports such as ice hockey in Canada may be under threat from global warming.