Winner 2013 Webby Awards for Best Political Website
Top Banner, Site wide
Apr 20, 2014

 Choose a size
Text Size

Top Leaderboard, Site wide

First Solar Bread Oven Takes a Bow
Drought Adds to Syria’s Misery




The Divide


Truthdig Bazaar
The Idea of Justice

The Idea of Justice

By Amartya Sen
$19.77

Citizen Stan

Citizen Stan

By Patty Sharaf with Robert Scheer
$15.00

more items

 
Report

Polar Ice Melt Will Mean Uneven Sea-Level Rise

Email this item Email    Print this item Print    Share this item... Share

Posted on Feb 21, 2013
Jesse Gardner (CC BY-SA 2.0)

By Alex Kirby, Climate News Network

The piece originally ran on Climate News Network.

LONDON—Scientists say the sea-level rise caused by climate change during the rest of this century will not affect all parts of the world equally, because of the ways sea, land and ice interact.

They say parts of the Pacific are likely to see the highest rise. This region is where many low-lying island countries most vulnerable to sea level rise, like the Seychelles, are already struggling. Their peoples will need evacuation if the scientists’ high-end predictions are correct. Northern Europe, on the other hand, will experience a below-average increase.

The team, from Italy’s University of Urbino and the University of Bristol, UK, report their findings in a paper, The gravitationally consistent sea-level fingerprint of future terrestrial ice loss, published in Geophysical Research Letters online.

Scientists have known for some time that sea level rise around the globe will not be uniform. The team investigated how ice loss will continue to add to rising sea levels until the year 2100. The researchers, from the European Union’s Ice2sea project, show in detail the global pattern of sea-level rise that would result from two scenarios of ice-loss from glaciers and ice sheets.

Advertisement

Square, Site wide
Improved projections of the contribution of ice to sea-level rise produced by Ice2sea will feed into the fifth assessment report of the Intergovernmental Panel on Climate Change. In 2007, the IPCC’s fourth report highlighted ice-sheets as the most significant remaining uncertainty in projections of sea-level rise.

The researchers found that ice melt from glaciers and from the Greenland and Antarctic ice sheets is likely to be critically important to regional sea-level change in the equatorial Pacific ocean.

Legacy of the Ice Age

There the rise will be greater than the global average increase, affecting in particular western Australia, Oceania and the small atolls and islands in the region, including Hawaii. Another area which should expect an above-average increase is the east coast of South Africa and Madagascar.

The study focussed on three effects that lead to the unequal distribution of sea-level rise. First, land is both subsiding into and emerging from the sea because of a massive ice loss at the end of the last Ice Age 10,000 years ago, when billions of tonnes of ice covering parts of North America and Europe melted.

This caused a major redistribution of mass on the Earth, but the crust responds to such changes so slowly that it is still changing shape. Secondly, the warming of the oceans changes the distribution of water across the globe.

The third effect is the way the sheer mass of frozen water on Antarctica and Greenland exerts a gravitational pull on the surrounding liquid water, pulling in enormous amounts and raising the sea-level close to the coasts. As the ice melts its pull decreases and the water previously attracted pours away, to be redistributed around the globe.

Co-author Professor Giorgio Spada said: “The most vulnerable areas are those where the effects combine to give the sea-level rise that is significantly higher than the global average.” In Europe the level would rise, but it would be slightly lower than the average.

“We believe this is due to the effects of the melting polar ice relatively close to Europe – particularly Greenland’s ice”, he said. “This will tend to slow sea-level rise in Europe a little, but at the expense of higher sea-level rise elsewhere.”

The team considered two scenarios in its modelling. One was the “most likely” or “mid-range” and the other closer to the upper limit of what could happen.

Stark contrast

Professor Spada said: “The total rise in some areas of the equatorial oceans worst affected by the terrestrial ice melting could be 60cm if a mid-range sea-level rise is projected, and the warming of the oceans is also taken into account.”

Another co-author, Jonathan Bamber, professor of physical geography at Bristol University, UK, told the Climate News Network: “Northern Europe will be influenced by mass loss from Greenland, and places like Scotland and Scandinavia will probably see close to zero sea-level rise from the melting ice, leaving aside thermal expansion of the sea.

“But if you take the high-end scenario, there’s a reasonable chance the rise could reach a metre in the western Pacific.”

Professor David Vaughan, Ice2sea programme coordinator, said: “The urgent job now is to understand how the global sea-level rise will be shared out around the world’s coastlines. Only by doing this can we really help people understand the risks and prepare for the future.”

A spokesman for the Association of Small Island States (Aosis), told a UN climate conference two years ago that whole nations would be washed away by sea level rise.

He said the people of Kiribati, Tuvalu, most of the Cook Islands, the Marshall Islands and the Maldives, which are just a few metres above sea level now, could be lost.


New and Improved Comments

If you have trouble leaving a comment, review this help page. Still having problems? Let us know. If you find yourself moderated, take a moment to review our comment policy.

Newsletter

sign up to get updates


 
 
Right 1, Site wide - BlogAds Premium
 
Right 2, Site wide - Blogads
 
Join the Liberal Blog Advertising Network
 
 
 
Right Skyscraper, Site Wide
 
Join the Liberal Blog Advertising Network
 

A Progressive Journal of News and Opinion   Publisher, Zuade Kaufman   Editor, Robert Scheer
© 2014 Truthdig, LLC. All rights reserved.

Like Truthdig on Facebook