2 February, 2005

The contribution that rapid thinning of the Antarctic ice sheet is making to global sea-level rise is a cause for concern according to Director of British Antarctic Survey (BAS), Professor Chris Rapley. Speaking this week at a conference* hosted by the Met Office in Exeter he summarised the latest understanding from one of the frozen continent?s most remote and inhospitable corners.

Professor Rapley said,
?Satellite measurements tell us that a significant part of the West Antarctic ice sheet in this area is thinning fast enough to make a significant contribution to sea level rise, but for the present, our understanding of the reason for this change is little better than hypothesis. The last IPCC report characterised Antarctica as a slumbering giant in terms of climate change. I would say that this is now an awakened giant. There is real cause for concern.?

In recent years two major glaciers in the Amundsen Sea sector of the West Antarctic ice sheet have shown rapid thinning. This prompted scientists from BAS, US National Science Foundation and the University of Texas to embark on an airborne geophysical survey of the least visited and unknown areas of the continent. Using two Twin Otter aircraft kitted out with a suite of survey instruments, the scientists collected data from Pine Island and Thwaites glaciers.

Predictions made by BAS scientists in 1998 that the warming experienced in the Antarctic Peninsula region would put several ice shelves at risk was dramatically realised in 2002 when, in less than a month, 500 billion tonnes of ice from the Larsen B ice shelf broke up into thousands of small icebergs. The latest published research shows that as a result of the ice shelf collapse, the glaciers that fed the ice shelf have accelerated and thinned dramatically. This suggests that ice shelves may have an important role in stabilising the ice sheet in Antarctica, and imply that the future loss of the largest ice shelves in the Antarctic could eventually cause accelerated and dramatic sea level rise.

 

Issued by the British Antarctic Survey Press Office.
Linda Capper ? tel: ++44 1223 221448, mob: 07714 233744, email: l.capper@bas.ac.uk
Athena Dinar ? tel: ++44 1223 221414, mob:07740 822229, email: a.dinar@bas.ac.uk

Met Office Press Office +44 (0)1392 886655
E-mail: pressoffice@metoffice.gov.uk
Defra Press Office +44 (0)20 7238 5599

NOTES TO EDITORS:
Contact the BAS Press Office to receive an abstract of Professor Rapley?s presentation.

*The conference, Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilisation of Greenhouse Gases, is focussed on the scientific aspects of stabilising climate change, The Met Office’s Hadley Centre for Climate Prediction and Research is delighted to be hosting the conference of around 200 internationally renowned scientists at its new headquarters in Exeter from 1-3 February 2005. The Met Office Hadley Centre for Climate Prediction and Research is the UK’s leading centre for climate research and is based in Exeter.

In 2001 the Intergovernmental Panel on Climate Change (IPPC) predicted future sea level rise on the assumption that the Antarctic ice sheet would not make a significant contribution over the next one hundred years. Recent data from the Pine Island and Thwaites glaciers in Antarctica suggest that this area is making a contribution, but whether this is a short-term fluctuation, or a result of recent or ancient climate change, is an open question. Our ability to predict the future of this part of the West Antarctic ice sheet is limited and basic information such as the ice sheet thickness and conditions beneath the ice at bedrock are required to build numerical models that will allow robust prediction.

British Antarctic Survey is a world leader in research into global issues in an Antarctic context. It is the UK?s national operator and is a component of the Natural Environment Research Council. It has an annual budget of around ?40 million, runs nine research programmes and operates five research stations, two Royal Research Ships and five aircraft in and around Antarctica.

Prof Chris Rapley CBE is Director of the British Antarctic Survey (BAS). Prior to this he was for four years the Executive Director of the International Geosphere-Biosphere Programme (IGBP) at the Royal Swedish Academy of Sciences in Stockholm. This followed an extended period as Professor of Remote Sensing Science and Associate Director of University College London’s Mullard Space Science Laboratory. He has a first degree in physics from Oxford, a M.Sc. in radioastronomy from Manchester University, and a Ph.D. in X-ray astronomy from University College London. He has been a Principal Investigator on both NASA and European Space Agency satellite missions and is a member of the NASA JPL Cassini mission Science Team. He has been a member of numerous national and international committees and boards including Vice President of the Scientific Committee for Antarctic Research and Chair of the International Council for Science’s (ICSU) International Polar Year 2007-2008 (IPY) Planning Group. He is currently a member of the European Polar Board’s Executive and ICSU – World Meteorological Organisation (WMO) Joint Committee for IPY. He is a Fellow of St Edmund’s College Cambridge, and is an Honorary Professor at University College London and at the University of East Anglia.