Dramatic Change In West Antarctic Ice
Produce 16ft Rise In Sea Levels
Michael McCarthy, February 2, 2005
British scientists have discovered a new threat to the
world which may be a result of global warming. Researchers
from the Cambridge-based British Antarctic Survey (BAS)
have discovered that a massive Antarctic ice sheet previously
assumed to be stable may be starting to disintegrate,
a conference on climate change heard yesterday. Its
collapse would raise sea levels around the earth by
more than 16 feet.
staff are carrying out urgent measurements of the remote
points in the West Antarctic Ice Sheet (WAIS) where
they have found ice to be flowing into the sea at the
enormous rate of 250 cubic kilometres a year, a discharge
alone that is raising global sea levels by a fifth of
a millimetre a year.
Chris Rapley, the BAS director, told the conference
at the UK Meteorological Office in Exeter, which was
attended by scientists from all over the world, that
their discovery had reactivated worries about the ice
four years ago, in the last report of the UN's Intergovernmental
Panel on Climate Change (IPCC), worries that the ice
sheet was disintegrating were firmly dismissed.
Rapley said: "The last IPCC report characterised
Antarctica as a slumbering giant in terms of climate
change. I would say it is now an awakened giant. There
is real concern."
added: "The previous view was that WAIS would not
collapse before the year 2100. We now have to revise
that judgement. We cannot be so sanguine." Collapse
of the WAIS would be a disaster, putting enormous chunks
of low-lying, desperately poor countries such as Bangladesh
under water - not to mention much of southern England.
conference has been called by Tony Blair as part of
Britain's efforts to increase the pace of international
action on climate change, in a year when the UK is heading
the G8 group of industrialised nations and the European
Blair has asked it to explore the question of how much
climate change the world can take before the consequences
are catastrophic for human society and ecosystems.
it heard several alarming new warnings of possible climate-related
catastrophic events, including the failure of the Gulf
Stream, which keeps the British Isles warm, and the
melting of the ice sheet covering Greenland.
it was the revelations of Professor Rapley, head of
one of the world's most respected scientific bodies,
which were the most dramatic, as they reopened a concern
many scientists assumed had been laid to rest.
as a whole is a land covered by very thick ice, but
the ice sheet covering the eastern half of the continent
is very stable as it sits on rocks that are well above
about the ice covering the western half first surfaced
more than 25 years ago when it was realised that the
base rocks are actually well below the level of the
some circumstances, it was feared, such as a melting
of the edge of the ice sheet from rising temperatures,
sea water could get under it and eventually lead to
the 2001 IPCC report, the principal consensus view of
the international community of climate scientists, thought
that very unlikely, and said such a collapse was improbable
before the end of the current century, or even for 1,000
puts a very big question mark over this, Professor Rapley
said, was the recent discovery of the extremely rapid
discharge of ice into the Amundsen sea from the WAIS
at three remote ice streams, Pine Island, Thwaites,
and another unnamed site.
is a very dramatic discharge from this region which,
five years ago when the IPCC report was written, we
just didn't know about," he said. "What we
have found completely opens up the whole debate."
It had only been recently discovered, he said, because
the area was so remote. But BAS scientists, with US
help, had established a base in the area to investigate.
Professor Rapley said there was some evidence that the
discharge was a relatively recent phenomenon and it
might be caused by rising ocean temperatures.
Beckett, the Environment Secretary, who opened the conference,
added another ominous prediction when she said that
major global warming impacts on the world in the next
20 to 30 years could not be avoided. Whatever we do,
potentially disastrous world temperature rises will
take place because they are already "built into
the system," she said.
forecast that we are powerless to prevent major damage
from climate change is accepted by scientists but it
is rare for such a frank admission from a politician.
It reflects the concern at a high level.
was amplified by senior climate researchers, who said
the amount of future warming to which the world is firmly
committed, because of greenhouse gases that have already
been put into the atmosphere, will be enough to threaten
the survival of many ecosystems and wildlife species
such as polar bears and penguins.
believe that most of the warming we are expecting over
the next few decades is now virtually inevitable, and
even in this time frame we may expect a significant
impact," Mrs Beckett said.