Expert judgement provides better understanding of the effect of melting ice sheets

Melting ice sheets in Greenland and the Antarctic, and subsequent sea level rise (SLR) this will cause, is widely recognised as posing a significant threat to coastal communities and ecosystems. Strategies and measures to mitigate and plan for the potential impacts are reliant on scientific projections of future SLR - conventionally provided using numerical modelling. Such projections remain challenging due to ongoing uncertainty regarding the evolution of the Greenland and Antarctic ice sheets, particularly in response to climate change. Using a technique called structured expert judgment (SEJ), an international team of scientists, led by the University of Bristol, asked 22 ice sheet experts to estimate plausible ranges for future sea level rise due to the projected melting of each of the Greenland, West Antarctic and East Antarctic ice sheets under low and high future global temperature rise scenarios. Their findings are published this week in the journal Proceedings of the National Academy of Sciences of the United States of America . Lead author Professor Jonathan Bamber from the University of Bristol's School of Geographical Sciences , said: "SEJ provides a formal approach for estimating uncertain quantities based on current scientific understanding, and can be useful for estimating quantities that are difficult to model.