Subscribe free to our newsletters via your
. Earth Science News .

Subscribe free to our newsletters via your

Greenland's Jakobshavn glacier sounds climate change alarm

by Staff Writers
Jakobshavn Glacier, Greenland (AFP) Sept 19, 2007
The chaotic cavalcade of blueish ice tumbling into the sea from the world's fastest-moving glacier is sounding a daily climate change alarm, say scientists ahead of International Polar Day on Friday.

The Jakobshavn Glacier, on Greenland's west coast, is melting twice as fast as 10 years ago and advancing toward the sea at 12 kilometres (seven miles) per year, compared with six kilometres (three and a half miles) before.

In its 4th Assessment report issued earlier this year, the UN's Intergovernmental Panel on Climate Change (IPCC) said the world's oceans could rise by 50 centimeters (20 inches), putting tens of millions, perhaps hundreds of millions of people at risk by century's end.

But that estimate does not factor in the latest findings about the melting of glaciers in Greenland and loss of ice in Antarctica, which many experts say could eventually increase sea levels, and the rate at which they rise, by several fold.

Jakobshavn, moving toward the ocean at a clip of 30 to 40 metres a day, is but a single icy tongue reaching out from the Greenland icesheet, a massive block of ice and snow up to three kilometres (1.9 miles) thick covering 80 percent of the island, which is four times the size of France.

If the sheet's entire 2.85 million cubic kilometres (685,000 cubic miles) of ice were to melt, it would lift sea levels by seven metres (23 feet), swamping every major coastal city in the world.

Even in worst-case scenarios, such a meltdown would happen over centuries, not decades. But what scientists fear most is the "tipping point" beyond which the loss of ice becomes a self-reinforcing, positive feedback loop.

As sea ice -- the focus of the International Polar Day -- continues to recede, it gives rise to a phenomenon called albedo.

Albedo is the reflectivity of light. Because sea ice has a bright surface, most of the solar energy that strikes it is reflected back into space.

When that ice covering is replaced by dark-blue sea, however, the heat is absorbed, thus accelerating the melt.

"Over the last 30 years, temperatures have been rising twice as fast at the poles as the rest of the planet, which means that if we are looking at a global rise of 2 degrees C (3.6 F) by century's end, we will probably have an increase of 4 degrees C (7.2 F) here," said French scientist Jean Jouzel, accompanying French environment minister Jean-Louis Borloo to Greenland on a fact-finding mission.

These rising temperatures have resulted in a dramatic shrinkage of the ice covering the Arctic, with the total surface area dropping from four to three million square kilometres (1.15 million square miles) in just one year, the European Space Agency (ESA) said last week.

That has created a lot of newly-exposed blue water, and is tenfold the yearly average of ice cover lost over the previous decade.

Jakobshavn, meanwhile, continues to melt as it races -- by glacial standards -- toward the sea.

"In 1996, the glacier shed 27 cubic kilometers (6.5 cubic miles) of water per year, and today it is 50 km3 (12 cu. miles) per year. It is already too late to stop this movement, but we have compelling reasons to try to keep the temperature of the planet close to its current level," said Jouzel.

For now, Greenland accounts for about 15 percent of the world's rise in sea levels. No one can say what that figure will be in a decade or a century, but the trend is clear, said another French climatologist, Herve Le Treut.

"What is sure is that there is no way to reverse the mechanism, and we are almost sure that it will continue to rise," he said.

The International Polar Year 2007-2008 is a multi-national research effort involving 50,000 scientists from over 60 countries. Their aim is to better understand the polar regions -- their ecology and biodiversity, geological history, relation to climate change -- and raise public awareness.

Email This Article
Comment On This Article

Related Links
Beyond the Ice Age

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

In Ladakh, glacier melt raises fears of water woes
Leh, India (AFP) Sept 19, 2007
Rinchen Wangchuck remembers slipsliding his way down a glacier that stretched far down the mountains toward his village in the Nubra Valley, in India's far north, after school ended for the summer.

  • Malaysia's Smart Satellite Teleport Plays Role In Tsunami Warning
  • When The Levees Fail
  • Japan holds disaster drills to prepare for big quake
  • Devastated New Orleans mourns Katrina dead two years on

  • Increase In Atmospheric Moisture Tied To Human Activities
  • Climate talks in Montreal to take dual aim
  • Climate change tops future humanitarian challenges: Annan
  • Climate change and desertification two sides of same coin

  • New Faraway Sensors Warn Of Emerging Hurricane's Strength
  • Key Sensor For Northrop Grumman NPOESS Program Passes Critical Structural Test
  • Air France And ESA Join To Offer Passengers Unique View Of Voyage
  • NASA Scientist Treks To Burning Man Festival

  • EU New Policy Plan Targets Energy Giants
  • Analysis: Venezuela, Russia team up on oil
  • From plate to engine: French city powers buses with food scraps
  • Government Initiatives Drive Latin American Renewable Energy Markets

  • China confirms bird flu outbreak: HK official
  • Expert says climate change will spread global disease
  • Northern Iraq battles cholera 'epidemic'
  • Researchers Discover New Strategies For Antibiotic Resistance

  • UT Researcher Sheds New Light On Hybrid Animals
  • Hungry bears plague US west after record drought
  • DNA barcoding: from fruit-flies to puffer fish
  • 'Global extinction crisis' predicted by conservation group

  • International Team Shows Mercury Concentrations In Fish Respond Quickly To Increased Deposition
  • Landfill Mining
  • Hong Kong must cut pollution to attract foreign cash: study
  • Pesticide blamed for 'health disaster' in French Caribbean

  • Toddler And Ape Study Reveals Higher Social Skills Are Distinctly Human
  • Primates Expect Others To Act Rationally
  • Study Identifies Key Player In The Body's Immune Response To Chronic Stress
  • Human Testes May Multiply Mutations

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement