Ice station zero
An iceberg carved off an ice sheet near the South Orkney Islands, Antarctica
Natural Environment Research Council.
We know that the Earth is warming, and at first glance, it might be easy to make the connection between increased atmospheric temperatures, melting ice sheets and a rise in sea level. But the reality is much more complex.
A team of UK oceanographers and glaciologists has recently returned from the Antarctic where they have been looking for ways to explain why, in places, the ice sheets are thinning. These expanses of ice depend on an equilibrium between build up from snowfall on top, and melting into the oceans below. Satellite data have shown that in a certain part of Antarctica this balance is shifting. Combined with underwater measurements, these data will help explain how and why such changes are occurring. This will in turn improve our models for predicting the effects of future climate change, and inform policy makers on how to respond better to the challenges that these changes may pose.
Satellite measurements and underwater technology have shown that some sections of the West Antarctic Ice Sheet that float on water are melting much faster than previously thought. Scientists at the British Antarctic Survey are tracking how recent climate changes might cause more warm water to flow under the ice sheets, increasing the rate at which they melt. Meanwhile work at the Scott Polar Research Institute suggests that the explanation may lie with a much earlier climate change at the end of the last glacial period 20,000 years ago. A model developed by scientists at University College London demonstrates the inherent dynamic behaviour of ice sheets.
Each of these accounts has its own implications for predicting how fast the ice sheet may melt in the future, and what practical steps we might be able to take to slow it down. Understanding exactly what lies behind the fragility of the ice sheets has important implications for all of us. If the West Antarctic Ice Sheet were lost, global sea level could rise by 5 metres, threatening coastal populations throughout the world. The mass of ice at the poles influences ocean circulation, driving deep, cold water northwards, thus affecting climates many thousands of miles away.
'Science is all about considering a problem from different angles,' explains Professor John Lawton, Chief Executive of the Natural Environment Research Council, which funds this work.
British Antartic Survey
Natural Environment Research Council