Antarctica – an awakening giant?

The crucial role that Antarctica plays in global climate change and its future contribution to sea-level rise was highlighted today by Professor Chris Rapley, Director of British Antarctic Survey (BAS). Speaking at an international convention on climate change in Bonn, Germany* he presented a summary of the latest scientific results from Antarctica.

Professor Rapley said, “The issue of sea-level rise is of great concern to all of us – the contribution from Antarctica is the greatest uncertainty in the sea level rise debate. The last IPCC (Intergovernmental Panel on Climate Change – 2001) report warned that Antarctica was a ‘slumbering giant’. Recent scientific evidence leads us to believe that the giant is waking up. Policy-makers need to know what the consequences will be for society.”

Computer models suggest that the East Antarctic Ice Sheet may thicken as a result of climate change, but observations from satellites and aircraft show that two other areas are thinning. These conflicting effects and the challenge of measuring them make it difficult at present to predict the contribution of Antarctica to sea level rise, there is no doubt that its role will be significant.

In the last 50 years the Antarctic Peninsula has warmed faster than anywhere else on Earth. Predictions made by BAS scientists in 1998 that the warming threatened several ice shelves were realised in 2002 when, in less than a month, 3200 km2 of Larsen B ice shelf broke up into thousands of small icebergs. Recent research1 shows that as a result of ice shelf collapse, the glaciers that drained the peninsula have retreated1, thinned and accelerated dramatically2. BAS researchers have an urgent focus to assess how much these changes are contributing to sea level rise.

Elsewhere, satellite studies have shown that a large part of the West Antarctic Ice Sheet, which may be prone to collapse, has been shown to be thinning. Earlier this year BAS and US National Science Foundation and the University of Texas scientists completed a huge airborne survey of this, the least explored area of the West Antarctic. The scientists flew 100 000 km collecting data that will allow better prediction of the future contribution of West Antarctica to sea level rise.