Greenland ice melting raises risk for Bangladesh

Ice in Greenland is melting faster than scientists previously thought, with the pace of ice loss increasing four-fold since 2003, new research has found, quoting a Guardian report UNB says.

The research provides fresh evidence of the dangers posed to vulnerable coastal places as diverse as Bangladesh, USA’s Miami, China’s Shanghai and various Pacific islands as climate change shrinks the world's land-based ice, a scientific study says.

The study, published in Proceedings of the National Academy of Sciences, used data from Nasa's gravity recovery and climate experiment (known as Grace) and GPS stations scattered across Greenland to analyse changes in ice mass.

Enormous glaciers in Greenland are depositing ever larger chunks of ice into the Atlantic ocean, where it melts. But scientists have found that the largest ice loss in the decade from 2003 actually occurred in the southwest region of the island, which is largely glacier-free.

This suggests surface ice is simply melting as global temperatures rise, causing gushing rivers of meltwater to flow into the ocean and push up sea levels. South-west Greenland, not previously thought of as a source of woe for coastal cities, is set to "become a major future contributor to sea level rise," the research states.

This suggests surface ice is simply melting as global temperatures rise, causing gushing rivers of meltwater to flow into the ocean and push up sea levels.

Overall, the scientists said, the melt of Antarctica added water equivalent to 13.2 millimetres of sea level rise over the past four decades.

Arctic ice loss has tripled since the 1980s, with melting in places such as Greenland and Alaska providing the greatest instigator of sea level rise while destabilising the very ground underneath four million people's feet.

"We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers," said Michael Bevis, lead author of the paper and a professor of geodynamics at Ohio State University.

"But now we recognise a second serious problem: increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea."

Antarctica is becoming an increasing concern, however, with ice vanishing at its fastest rate in recorded history. The world's largest expanse of ice is now losing around 219bn tonnes of ice a year, a trajectory that would contribute more than 25cm to total global sea level rise by 2070.

Should the entire west Antarctic ice sheet collapse, sea levels would balloon by around 3.5m, albeit over a lengthy timeframe.