THINKING ABOUT ICE
It’s been a long time since we had any news about global warming but there have been some real chillers that have hit the news recently. Of course, ‘chillers’ isn’t really the right word!
GLACIALLY SPEAKING
Although you may not realize it; there’s a world-wide body that monitors glaciers; those slowly moving rivers of ice that are found in Antarctica and in mountain ranges all over the world. The World Glacier Monitoring Service at the University of Zurich has recently announced that data from more than 80 glaciers confirm that the ice loss from glaciers has been accelerating since 1980.
Michael Zemp, glaciologist and research associate of the WGMS, said: “The average ice loss in 2007 was not as extreme as in 2006, but there were large differences between mountain ranges. Glaciers in the European Alps lost up to 2.5 meters of ice, whereas maritime glaciers in Scandinavia were able to gain more than a meter in thickness. However, 2007 is now the sixth year of this century in which the average ice loss of the reference glaciers has exceeded half a meter. This has resulted in a more than doubling of the melt rates of the 1980s and 90s.”
In 2007, dramatic ice losses were reported from glaciers in the European Alps, and the Andes in South America. Some positive values were reported from the Northern Cascade Mountains and the Juneau Ice field in North America; but ice loss continued from the glaciers in the Kenai Mountains and the Alaskan Range as well as from Canada’s Coast Mountains and High Arctic.
The World Glacier Monitoring Service was initiated in 1894, following the example of the Swiss national observation network, and has been mainly under Swiss leadership since then. Today, the service is responsible for the collection and publication of standardized glacier data from around the world. The WGMS is located at the University of Zurich, Switzerland, and maintains a collaborative network of national correspondents and principal investigators in the countries involved in glacier monitoring. The long-term measurement series of glacier mass balance produces one of the essential variables within the international climate-related monitoring programs.
Monitoring glacial ice.
But glaciers aren’t the only place that ice loss is occurring. Here’s another ‘chilling’ (or warming) story that was in the news last weekend.
A BRIDGE COLLAPSE
An ice bridge which had held a vast Antarctic ice shelf in place for hundreds of years shattered on Saturday and may herald a wider collapse linked to global warming, a leading scientist said.
"It’s amazing how the ice has ruptured. Two days ago it was intact," David Vaughan, a glaciologist with the British Antarctic Survey, told Reuters of a satellite image of the Wilkins Ice Shelf. "We’ve waited a long time to see this."
The satellite picture, by the European Space Agency (ESA), showed that a 40-km (25 mile) long strip of ice believed to pin the Wilkins Ice Shelf in place had snapped at its narrowest point of about 500 meters wide off the Antarctic Peninsula. The break left a jumble of huge flat-topped icebergs in the sea. The loss of the ice bridge, which was almost 60 miles wide in 1950 and had been in place for hundreds of years , could allow ocean currents to wash away more of the Wilkins.
"My feeling is that we will lose more of the ice, but there will be a remnant to the south," Vaughan said. The remaining shelf is about the size of the U.S. state of Connecticut.
Temperatures on the Antarctic Peninsula, which snakes up toward South America, have risen by up to about 5 degrees F. in the past 50 years, the fastest rate of warming in the Southern Hemisphere.
"We believe the warming on the Antarctic Peninsula is related to global climate change, though the links are not entirely clear," Vaughan said. Antarctica’s response to warming will go a long way to deciding the pace of global sea level rise.
Nine other shelves have receded or collapsed around the Antarctic Peninsula in the past 50 years, often abruptly like the Larsen A in 1995 or the Larsen B in 2002 further north, and shrinking maps of the frozen continent. The trend is widely blamed on climate change caused by heat-trapping gases from burning fossil fuels. Vaughan landed on the narrow ice bridge, which jutted about 20 meters above the sea, in January with a group of scientists and two Reuters reporters. He predicted that it would snap this year.
Well, it turns out David Vaughn was right about the Wilkins Ice Shelf. And if the next prediction also comes true it could have devastating consequences for the whole world.
GOODBYE MIAMI (NEVERMIND NEW ORLEANS)
University of Toronto and Oregon State University geophysicists have shown that should the West Antarctic Ice Sheet collapse and melt in a warming world – as many scientists are concerned it will – the coastlines of North America and nations in the southern Indian Ocean will face the greatest threats from rising sea levels. The catastrophic increase in sea level, already projected to average between 16 and 17 feet around the world, would be almost 21 feet in such places as Washington, D.C., scientists say, putting it largely underwater. Many coastal areas would be devastated and much of Southern Florida would disappear.
The problem is that ice shelves like the Wilkins are already in the water. If they melt, they only add the 10 percent of their bulk that’s above the water. But the Ross Ice Shelf and the West Antarctic Ice Sheet are on land and if they collapse into the ocean not only will the rise in sea levels at most coastal sites be significantly higher than previously expected, but that the sea-level change will be highly variable around the globe.
The typical estimate of the sea-level rise is five metres or roughly 15 feet, a value arrived at by taking the total volume of the West Antarctic Ice Sheet, converting it to water and spreading it evenly across the oceans. But this is a simplification which ignores such factors as the effect of the removal of the ice load from the continent of Antarctica and the fact that the melting will cause the Earth’s rotational axis to shift dramatically; perhaps as much as 2000 feet from its present position. If the West Antarctic Ice Sheet collapses, sea level will fall close to the Antarctic and will rise much more than the expected estimate in the northern hemisphere.
The net effect of all of these processes is that if the West Antarctic Ice Sheet collapses, the rise in sea levels around many coastal regions will be as much as 25 per cent more than expected, for a total of between twenty and twenty-five feet if the whole ice sheet melts. That’s a lot of additional water, particularly around such highly populated areas as Washington, D.C., New York City, and the California coastline.
And of course, the real problem is not that a lot of people will die in an event like this but that not nearly enough of them will. The seas would rise slowly enough that virtually everyone would be able to escape the rising water . . . . and where would they go? All of a sudden, you would have MILLIONS of people in the interiors of continents with no homes and no jobs. Think the effects of Katrina were bad?? There’s a real possibility you ain’t see nothing yet!
Cruise on over to the Deep Website at www.thedeepradioshow.com to learn more about global warming and many other topics. Enjoy!
