Lines on this satellite image
of Greenland's Helheim glacier show the positions of the glacier front between
2001 and 2005. Image: I. Howat et al.
Greenland's glaciers have begun to race towards the ocean, leading
scientists to predict that the vast island's ice cap is approaching irreversible
meltdown, The Independent on Sunday can reveal.
Research to be published in a few days' time shows how glaciers that have been
stable for centuries have started to shrink dramatically as temperatures in
the Arctic have soared with global warming. On top of this, record amounts of
the ice cap's surface turned to water this summer.
The two developments - the most alarming manifestations of climate change to
date - suggest that the ice cap is melting far more rapidly than scientists
had thought, with immense consequences for civilisation and the planet. Its
complete disappearance would raise the levels of the world's seas by 20 feet,
spelling inundation for London and other coastal cities around the globe, along
with much of low-lying countries such as Bangladesh.
More immediately, the vast amount of fresh water discharged into the ocean
as the ice melts threatens to shut down the Gulf Stream, which protects Britain
and the rest of northern Europe from a freezing climate like that of Labrador.
The revelations, which follow the announcement that the melting of sea ice
in the Arctic also reached record levels this summer, come as the world's governments
are about to embark on new negotiations about how to combat global warming.
This week they will meet in Montreal for the first formal talks on whether
there should be a new international treaty on cutting the pollution that causes
climate change after the Kyoto protocol expires in seven years' time. Writing
in The Independent yesterday, Tony Blair called the meeting "crucial",
adding that it "must start to shape an inclusive global solution".
But little progress is expected, largely because of continued obstruction from
President George Bush.
The new evidence from Greenland, to be published in the journal Geophysical
Research Letters, shows a sudden decline in the giant Helheim glacier, a river
of ice that grinds down from the inland ice cap to the sea through a narrow
rift in the mountain range on the island's east coast.
Professor Slawek Tulaczyk, of the Department of Earth Sciences at the University
of California, Santa Cruz, told the IoS that the glacier had dropped 100 feet
Over the past four years, the research adds, the front of the glacier - which
has remained in the same place since records began - has retreated four and a
half miles. As it has retreated and thinned, the effects have spread inland "very
fast indeed", says Professor Tulaczyk. As the centre of the Greenland ice
cap is only 150 miles away, the researchers fear that it, too, will soon be affected.
The research echoes disturbing studies on the opposite side of Greenland: the
giant Jakobshavn glacier - at four miles wide and 1,000 feet thick the biggest
on the landmass - is now moving towards the sea at a rate of 113 feet a year;
the normal annual speed of a glacier is just one foot.
The studies have found that water from melted ice on the surface is percolating
down through holes on the glacier until it forms a layer between it and the
rock below, slightly lifting it and moving it toward the sea as if on a conveyor
belt. This one glacier alone is reckoned now to be responsible for 3 per cent
of the annual rise of sea levels worldwide.
"We may be very close to the threshold where the Greenland ice cap will
melt irreversibly," says Tavi Murray, professor of glaciology at the University
of Wales. Professor Tulaczyk adds: "The observations that we are seeing
now point in that direction."
Until now, scientists believed the ice cap would take 1,000 years to melt entirely,
but Ian Howat, who is working with Professor Tulaczyk, says the new developments
could "easily" cut this time "in half".
There is also a more immediate danger as the melting ice threatens to disrupt
the Gulf Stream, responsible for Britain's mild climate. The current, which
brings us as much heat in winter as we get from the sun, is driven by very salty
water sinking off Greenland. This drives a deep current of cold ocean southwards,
in turn forcing the warm water north.
Research at the Woods Hole Oceanographic Institute in Massachusetts has shown,
that even before the glaciers started accelerating, the water in the North Atlantic
was getting fresher in what it describes as "the largest and most dramatic
oceanic change ever measured in the era of modern instruments".
Even before these discoveries, scientists had shortened to evens the odds on
the Gulf Stream failing this century. When it failed before, 12,700 years ago,
Britain was covered in permafrost for 1,300 years.