Delivery to the IPCC
The 2007 Intergovernmental Panel on Climate Change (IPCC) report highlighted ice-sheets as the most significant remaining uncertainty in projections of sea-level rise. In particular, understanding of the crucial ice-sheet effects was “too limited to assess their likelihood or provide a best estimate of and upper bound for sea-level rise.” Several substantial science programmes now aim to address this significant science question.
The ice2sea programme’s main objective is to build a scientific foundation for policy development surrounding sea-level rise. Improved projections of the contribution of glaciers and ice-sheets to sea-level will be provided to the 2013 IPCC report (AR5) and European policy makers, providing them with the best basis for coastal defence planning.
Sea-level projections are expected from ice2sea in July 2012, in time to feed into the next report of the IPCC, but early results are already being delivered. There is increasing evidence that the loss of ice from polar ice-sheets is caused not by warming air, but by the warming waters produced as ocean circulation patterns begin to change. Projections of ocean change in the fjords around Greenland and the frigid seas around Antarctica show that this is likely to continue in future.
The ice2sea programme is ambitious, but one whose results will be of real value to engineers and planners across Europe. The sea-level projections it will produce will provide a sound basis for risk management in coastal cities and habitats. It is a good example of what can be achieved by funding scientific collaboration across national boundaries. But ice2sea will have another legacy – the programme is training a new generation of early-career researchers who will be capable of taking the work forward in future and further reduce the uncertainties surrounding sea-level rise, and the risks to our coasts.
The IPCC AR5 Report is due to be finalised in September 2012, with publication planned for early-2013. In brief, ice2sea will provide the following elements that may be used to inform the report:
- Improved understanding of the key processes that control how glacial systems respond to atmospheric and oceanic climate change.
- New methodologies for the prediction of global sea-level rise based on improved models of the response of ice sheets and mountain glaciers to climate change.
- Updated assessments of the likely contribution of the cryosphere to sea-level rise over the next 200 years, based on two emissions scenarios.
- A collective view of the likelihood of catastrophic sea-level rise, due to a collapse of either the Greenland or Antarctic ice sheets.
- A clearer view of where the uncertainties in predicting future sea-level rise arise, and how these may be reduced in future.