Ice sheet melt sets new record

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 22 January 2011

New research shows that 2010 set new records for the melting of the Greenland Ice Sheet, expected to be a major contributor to projected sea level rises in coming decades.

The shocking rate of Greenland’s ice melt is a wakeup call

“This past melt season was exceptional, with melting in some areas stretching up to 50 days longer than average,” said Dr. Marco Tedesco, Director of the Cryospheric Processes Laboratory at the City College of New York (CCNY – CUNY), who is leading a project studying variables that affect ice sheet melting.

“Melting in 2010 started exceptionally early at the end of April and ended quite late in mid- September.”

The study, with different aspects sponsored by World Wildlife Fund (WWF), the US National Science Foundation (NSF) and NASA, examined surface temperature anomalies over the Greenland ice sheet surface, as well as estimates of surface melting from satellite data, ground observations and models.

In an article published today in Environmental Research Letters, Dr. Tedesco and co-authors note that in 2010, summer temperatures up to 3°C (5.4°F) above the average were combined with reduced snowfall.

The capital of Greenland, Nuuk, had the warmest spring and summer since records began in 1873. Continue reading

Greenland ice sheet retreating and thinning

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 30 December 2010

A glaciologist is warning that the Greenland ice sheet is “retreating and thinning extensively” after a year of record-breaking high temperatures.

2010 was a record-breaking year marked by very warm temperatures across Greenland. Photo: Getty images

Dr Alun Hubbard on Aberystwyth University says its future is “grim” but disputes claims by other experts that it could collapse within 50 years.

He maintains it would be at least 100 to 1,000 years before it “potentially passes any point of no return leading to any widespread collapse”.

Dr Hubbard and his team have been analysing the results of a summer-long expedition.

His team of 15 from Aberystwyth and Swansea universities spent five months on the ice sheet from the beginning of May.

The group camped about 70 miles (112km) up the sheet, and measured the thickness, speed, climate, and other vital statistics using radar, seismic and geophysical equipment.

They found rising temperatures had caused extensive melting in new upper parts of the ice sheet in this “very sensitive polar region of the planet”.

This has generated at least double the quantity of melt water, compared with 2009, which runs off the ice sheet into the Atlantic and Arctic oceans.

There are fears the melting of the entire sheet could raise sea levels globally by about 7m (20ft), and a study last year found it was losing its mass faster than in previous years. Continue reading

Glacier slides twice as fast towards the sea

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 10 May 2010

A glacier in Greenland slides up to 220 percent faster towards the sea in summer than in winter and global warming could mean a wider acceleration that would raise sea levels, according to a study published on Sunday.

An iceberg carved from a glacier floats in the Jacobshavn fjord in south-west Greenland- Reuters

A group of experts led by Ian Bartholomew at Edinburgh University in Scotland said the variability was much stronger than earlier observations of glacier movement in Greenland.

The study, published in the journal Nature Geoscience, is a new piece of a puzzle to understand the world’s second biggest ice sheet behind Antarctica. Greenland has enough ice to raise world sea levels by about seven metres if it all melted.

The study said GPS satellite measurements of the glacier in south-west Greenland, up to 35km inland and at altitudes of up to 1 095m, showed that the ice in some places slid at 300m per year at peak summer rates.

“Our measurements reveal substantial increases in ice velocity during summer, up to 220 percent above winter background values,” it said.

The scientists said that the summer slide might be linked to melt water seeping under the ice. It did not speculate if the change in speed between summer and winter was part of natural shifts or was influenced by a changing climate.

But they wrote: “In a warming climate, with longer and more intense summer melt seasons, we would expect that water will reach the bed farther inland and a larger portion of the ice sheet will experience summer velocity changes.”

The United Nations panel of climate experts said in 2007 that global warming was unequivocal and that it was more than 90 percent certain that most warming in the past half century was caused by human activities led by the burning of fossil fuels.

The UN panel has come under fire this year after officials said its latest report in 2007 exaggerated the pace of melt of Himalayan glaciers by saying they might all disappear by 2035.

More than 250 members of the US National Academy of Sciences on Thursday defended climate change research against “political assaults”, and said that any delay in tackling global warming heightens the risk of a planet-wide catastrophe.

-Reuters