Climate reports agree that sea levels are rising, but predictions of how much they will rise this century vary widely. Tentative estimates come to a rise of a millimetre a year, but a rise of a metre or even more by the end of the century is not inconceivable.A major uncertain factor in these predictions is the extent of Greenland's land ice. A relatively small loss of one per cent of ice mass would already cause a sea level rise of six centimetres, so small uncertainties have big consequences. In the past, climate modelling researchers assumed partial solutions by specialising in the workings of the atmosphere, or the ocean, or the ice sheets. But the climate system does not function as a group of separate compartments: in reality, there is constant interaction between processes on a variety of time and space scales. Climate sensitivity is a resultant of feedbacks between land, atmosphere, ocean, sea ice and land ice. How do you build a model system that can predict future atmospheric warming, land ice melting and global sea level rise simultaneously and coherently?
Connecting character
This question lies in the domain of Earth System Modelling, the modelling of the Earth system. These computer models run on the largest supercomputers; this research requires cooperation between meteorologists, oceanographers, glaciologists and computer experts. This theme ties in with the European and global agendas focused on climate and water system.
