Study Suggests Himalayan Ice is Melting at a Slower Rate than Supposed

Published in peer-reviewed journal Nature this past week, a new study has found that the melt rate from the Himalayas, along with other high-elevation Asian mountains, is significantly lower than figures other studies have proposed.

Co-authored by Thomas Jacob, John Wahr, W. Tad Pfeffer, and Sean Swenson, the study relied on gravitational satellite monitoring, a deviation from more traditional ground studies done by scientists. The study’s findings are an even more prominent deviation, suggesting that from 2003 to 2010, the Himalayan ice melt was 4 billion tons a year, as opposed to the 50 billion tons a year that some scientists originally estimated.

That’s the good news. The bad news? The study confirmed old evidence that Antarctica and Greenland are melting at a rate of approximately 385 billion tons a year, making them the major players in the battle with ice melt.

“It’s Greenland and Antarctica that pose by far the greatest threat to rising sea levels in the future,” said Wahr in an interview with MSNBC. “That’s, basically, where all the ice is.”

And unfortunately, there’s more bad news. The discrepancies between previous and recent data support the stance of nonbelievers who claim that studies on glacial melting and global warming rates have been conflicting and spotty.

Yet the study’s authors account for the difference.

“Most previous global mass balance estimates for GICs [glaciers and ice caps] rely on extrapolation of sparse mass balance measurements representing only a small fraction of the GIC area,” reads the abstract, “leaving their overall contribution to sea level rise unclear.”

The authors go on to warn about extrapolation in their own study, noting that inconsistency and changing factors in the region make data from the time period examined obsolete when predicting future melt rates.

However, while the study may not indicate future trends, it may change how future trends are calculated. The study’s technique relied on a satellite, christened GRACE, that “[mapped] out the Earth’s gravity field, all over the globe, every month,” according to Wahr.

The method’s basic mechanism is surprisingly simple. As Wahr explains, “One way to think of this is that as GRACE passes over Alaska, say, it feels the gravitational pull of all the Alaskan glaciers. When it passes over Alaska later on, it also feels the pull of all those glaciers, but now that pull is smaller because there is less mass in those glaciers to do the pulling. So you end up learning about the change in the cumulative mass of all those glaciers. You don’t miss any of the glaciers; you see the combined effects of all of them.”

Those “combined effects,” he added, are one of the drawbacks to the method, though. The satellite makes scientists unable to isolate the effects of an individual glacier.

Yet the study’s overall impact is not getting bogged down by the details. Scientists and concerned members of the public alike stress that while melt rate figures are more optimistic than originally presumed, they still pose a global problem, requiring global effort and global cooperation.

Photo Credit: wikimediafoundation.org/wiki/File:Himalayas-Lhasa11.JPG

Canadian Ice Shelves Rapidly Disappearing

According to new research published by Canadian scientists, two Canadian Arctic ice shelves have diminished by almost half in the last six years, damage that is most likely irreversible. The damage to the ice shelves was especially accelerated this past summer, when the largest ice shelf split in two; the other ice shelf has almost completely disappeared.

Ice shelves first began to form around 4,500 years ago and are much thicker than sea ice. Ice shelves in the Arctic region are the result of an accumulation of snow, sea ice, and occassionally glacial runoff. The ice shelves in the Arctic are, on average, 131 feet thick but can be as thick as 328 feet.

The two Arctic ice shelves were first discovered by researchers more than 100 years ago, when they were significantly larger than they are now. Research has indicated that between 1906 and 1982, there has been a 90 percent reduction in the amount of ice along Canada’s northern coastline. The Serson Ice Shelf and the Ward Hunt Ice Shelf, which were both included in the study, are the result of the Ellesemere Island Ice Sheet, which broke up into six pieces years ago. The other pieces that broke off from the Ellesmere Island Ice Sheet have already been significantly diminished. The remaining ice shelves now cover an estimated total of 402 square miles.

Scientists point to global warming as the reason the ice shelves are rapidly shrinking. Northern Ellesmere Island, which is where the Canadian ice shelves are located, has seen a 1.8 degree Fahrenheit rise in temperatures every decade for the past fifty to sixty years. Disappearing ice means that the level of the global ocean will rise significantly in the years to come, which could wreak havoc on the coastline’s ecosystems.

The Serson Ice Shelf, one of the two ice shelves included in the research, is located off the northern coastline of Canada’s Ellesemere Island. The shelf shrank from 79.15 square miles to two remaning section five years ago and diminished even further this past summer. One section of the shelf has gone from 16 square miles to 9.65 square miles, while the other section has gone from 13.51 square miles to 2 square miles.

The Ward Hunt Ice shelf, the second ice shelf included in the study, is also shrinking rapidly. This summer, the shelf’s central area, which was 131.7 square miles last year, broke up into two separate shelves. The remaining shelves now measure 87.65 and 28.75 square miles. The shrinking of the Ward Hunt Ice Shelf is especially troubling to scientists because it was located the furthest north and believe to be the most stable of the Arctic ice shelves.

The disappearing Canadian Arctic ice shelves are only the most recent problem facing the Arctic region in the face of global warming. The delicate region is experiencing temperature increases at a rate twice as fast as the rest of the world, which will only continue to melt the ice. Studies have shown that the permanent ice cover in the Arctic is diminishing by 9 percent every ten years; if this continues, the Arctic could be completely ice free by the end of the century.

In an unusual twist to the global warming debate, National Geographic posted an article last week describing the “bright side” of global warming’s affect on the Arctic: a new study has shown that “the changing climate could improve air quality in the polar region.” The improvement in air quality could be attributed to an increased amount of rainfall throughout the world, which is the most effective way of removing pollution from the air. As a result, the pollution that originates in other countries before traveling north to the Arctic would be diminished, allowing for improved air quality.

Photo Credit: epa.gov/climatechange/kids/images/2-1-8-photo1.jpg

Giant Floating Ice Sheet From Petermann Glacier Breaks In Two

[img_assist|nid=193214|title=|desc=|link=none|align=none|width=451|height=254]

Satellite image of ice sheet breaking in half.

Sept. 10, 2010 (GreenAnswers) – The giant 100 square mile ice block that broke off the Petermann Glacier in Greenland last month has severed into two giant pieces after colliding with Joe Island, a small rocky outcrop in the Nares Strait, west of Greenland.

The two separate ice blocks are still both larger than Manhattan island and combined could provide enough fresh drinking water to serve the entire U.S. demands for 120 days.

The original ice block had wedged up against Joe Island for about a week, where ocean currents and strong winds continued to push it into the rocky outcropping. These forces eventually caused the block to severe into two smaller, yet still giant, pieces.

As the two ice blocks migrate south, it is expected they will threaten shipping lanes and eventually make their way to the coasts of Newfoundland and Labrador in two or three years.

Although the breaking up of the ice block is a dramatic occurrence, researchers from the University of Delaware who are studying the original event on the Petermann Glacier, are more concerned with the causes of the initial break as well as the effects on the Greenland ice sheet, in general. 

“Because you’re changing the balance of forces by removing a large piece, what will happen next is that it will probably start moving forward faster than it has been before because it has to find a new equilibrium,” warned Andreas Muenchow, an associate professor at the University of Delaware.

Scientists are concerned the dramatic break on the Petermann Glacier and the overall shrinking of Greenland’s ice sheets are a result of climate change and that we are likely to see more dramatic events like these in the future.