Ice Cap Is Melting Fast
By Hamish Macdonell
07 August, 2004
Greenland's cover of ice is melting ten times quicker than previously
thought, an increase that could lead to floods across the world, scientists
research shows an alarming rise in the rate of collapse of the massive
Greenland ice-sheet as a result of global warming. Scientists now believe
the ice-sheet is shrinking at the rate of ten metres a year, not the
one metre previously thought.
If the entire ice-sheet
melts, the resulting flood waters would raise the level of global seas
by seven metres, submerging large areas of land, including sea-level
cities such as London.
Greenland has the
biggest ice-sheet in the northern hemisphere: almost 772,000 square
miles of ice which is up to 1.9 miles thick, the base of which is below
The new research
was published by the Geological Survey of Greenland and Denmark, which
has been monitoring the ice-sheet for several years. Icebergs from the
ice-sheet crash into the sea regularly, but they have been doing so
with increasing frequency over the past year.
The last major study
of Greenland was by NASA, the US space agency, four years ago. That
found that the surface of the ice was receding by one metre a year.
Carl Boggild, the
lead scientist, said the ice had dropped by two or three metres in just
the past few months.
"There is a
high melt rate due to warm winters and warm summers," he said.
of the Hadley Centre for Climate Prediction, at the University of Reading,
along with colleagues from Brussels and Bremerhaven, has also found
that an average annual warming in the region of 2.7C would mean that
the rate of melting would outpace the annual snowfall.
The greater the
warming, the faster the snow melts. The worst-case predictions for Greenland,
made by an inter-governmental panel of scientists, now involve an average
warming of 8C.
At those temperatures,
oceans that have risen by 2.5mm (less than one-tenth of an inch) a year
will start to rise by a steady 7mm a year.
side-effect of the destruction of the Greenland ice-sheet could be the
loss of the Gulf Stream, which keeps Europe warm and temperate. The
fresh water from the ice mixes with the salt water in the sea, altering
the salinity and changing the direction and behaviour of major currents.
The scientists on
the Greenland survey admit they have no way of setting any kind of timetable
to a rise in water levels or forms of climate change, and insist that
further monitoring will have to take place over the next few years to
get a clearer picture. But they do admit that their findings are worrying
and suggest a much more serious picture for global sea levels than had
been available up until now.
It is likely to
take hundreds of years for the entire ice-sheet to melt but, as this
years survey has shown, if the speed of the destruction increases,
that timescale could be brought forward dramatically.