Antarctic Ice Will Add to Global Sea Rise

A major new climate change study focused on Antarctica has predicted a circa 1.4 metre global sea level rise to take place by the end of the 21st century, as a result of polar ice melting.  The study was carried out by SCAR (the Scientific Committee on Antarctic Research), and details of it were unveiled to journalists present at a London press call on December 1st 2009.

“We can see the West Antarctic glaciers are shrinking at a rate fast enough to contribute to a sea level rise of 1.4 m by 2100 but it will be no more than that”, Colin Summerhayes – SCAR’s executive director – stated.  “We are ruling out some of the more extreme sea level rises (forecast) for the next 100 years”, he added.  “Those are unrealistic in light of all we know about ice shelves.”

Global Sea Level Rise

Two years ago, the UNIPCC (Intergovernmental Panel on Climate Change) issued a report predicting a global sea level rise of up to 59 centimetres by the end of 2099.  This, however, did not factor in the possible influence of melted ice from Antarctica and Greenland.  A more recent report, meanwhile, predicted an overall tidal rise of a maximum of two metres. 

The magnitude of SCAR’s new report is illustrated by data concerning its production.  100 scientists representing 13 nations participated, and it represents the first detailed assessment of the impact of climate change on Antarctica.  The date of its release coincides with the Antarctic Treaty’s 50th anniversary.

Antarctic Ice Melt

Here’s a round-up of some of the main points covered within the SCAR Antarctic ice melt report’s 400 pages:

• The majority of Antarctica has been shielded from climate change due to the hole in the ozone layer.  However, only 10 per cent of the Antarctic Peninsula’s glaciers remain
• The past three decades have seen an 11 per cent increase in Antarctic sea ice.  This is due to a combination of factors including atmospheric fluctuations, stronger wind gusts and the ozone hole.  Antarctic Peninsula ice, though, has been on a downslide as a result of climate change, with increased sea temperatures prompting ice fragmentation.
• The restoration of the ozone layer will likely lead to a two-fold greenhouse gas volume increase. 

“Over the next 100 years sea ice is going to decrease”, Summerhayes explained. “Ice is increasing at the moment but it won't be like that when the ozone hole goes and we will lose 33 per cent of sea ice.”

The situation will impact on the local ecosystem, the study stressed.  For example, the availability of krill – which penguins, fish and whales all feed on – is expected to drop 50 per cent.  Other types of marine life may face outright extinction while new types enter the scenario with potentially devastating results. 

The head editor involved in the study, Professor John Turner, stated: “For me the most astonishing evidence is the way that one man-made environmental impact – the ozone hole – has shielded most of Antarctica from another – global warming.”

He added: “This review is a major step forward in making sure that the latest and best evidence is available in one place.  It sets the scene for future Antarctic Research and provides the knowledge that we all need to help us live with environmental change.”

See also:

Antarctic Carbon Sink Discovered