Ice sheet retreat controlled by the landscape

Ice-sheet retreat can halt temporarily during long phases of climate warming, according to scientists. A UK team led by Durham University has found that the geometry of channels beneath the ice can be a strong control on ice behaviour, temporarily hiding the signals of retreat. The findings, which provide the first simulation of past ice-sheet retreat and collapse over a tenthousand year period in Antarctica, shed new light on what makes ice stable or unstable and will help refine predictions of future ice extent and global sea-level rise, the researchers say. The International Panel on Climate Change (IPCC) has stated that one of the main challenges in predicting future sea-level rise is to quantify and model the interactions between evolving ice sheets, oceans, sea level and climate. Significant efforts have been made over the last decade to develop computer models and collect data in order to reduce uncertainties and understand the potential impacts under scenarios of future climate change. The results of the new research from Durham University, the University of Sheffield, the University of Cambridge, and the British Antarctic Survey are published . Lead author Stewart Jamieson, a glaciologist at the Department of Geography, Durham University, said: "Our research shows that the physical shape of the channels is a more important factor in controlling ice stability than was previously realised.