The record length of satellite observations of mass loss from the Greenland and Antarctic ice sheets is currently too short to separate long-term trends from short-term natural variability, suggests a study published online in Nature Geoscience. The findings underscore the need for continuous satellite monitoring of the ice sheets to better identify and predict melting and the corresponding sea-level rise.

Bert Wouters and colleagues compared nine years of satellite data from the Gravity Recovery and Climate Experiment with reconstructions of about 50 years of mass changes to the ice sheets. They found that the ability to accurately detect an accelerating trend in mass loss depends on the length of the record. They suggest that although we may have almost enough satellite data to detect an acceleration in mass loss of the Antarctic ice sheet, we may need another ten years of satellite observations to do so for Greenland.

This finding challenges the notion that recent accelerations in melt will be sustained into the future, and urges caution in extrapolating current measurements to predict future sea-level rise.