Fluctuations in the mass of the Greenland and Antarctic ice sheets are of considerable societal importance as they impact directly on global sea levels: since 1901, ice losses from Antarctica and Greenland, alongside the melting of small glaciers and ice caps and thermal expansion of the oceans, have caused global sea levels to rise at an average rate of 1.7 mm/yr. Between 1992 and 2010 the rate of change, as measured by satellite altimetry and tide gauges, reached 3.2mm/yr. This translates as a total rise of 0.19 m in global mean sea level since the turn of the twentieth century (IPCC AR5).
Sea level rise is likely to continue at an even faster rate during the 21st century. It is also predicted to affect more than 95% of the world’s oceans by 2100, with 70% of coastlines experiencing rising sea levels.
Adapting to and mitigating the impacts of sea level rise relies upon accurate forecasts of its magnitude and rate. This in turn depends on our ability to measure and understand each contributor to sea level rise, including losses from the Greenland and Antarctic ice sheets.