Washington: Researchers suggest that the time period of satellite observations of the ice sheets of Greenland and the Antarctic is still too short to be able to predict whether the accelerated loss of ice measured today will persist in the future.
The researchers, led by Bert Wouters from the University of Bristol, conclude that predictions of the contribution of both ice shields to the sea level up to the year 2100 may be more than 35 cm too high or too low.
The researchers analyzed nine years` worth of data from the gravity field satellite GRACE.
The GRACE measurements showed that both ice sheets are losing significant amounts of ice - about 300 billion tons per year.
At the same time, the rate at with which these losses occur is increasing. The contribution of both ice shields to sea level rise in recent years has almost doubled when compared to the first years of the GRACE mission.
The causes of this accelerated reduction in ice mass are still a challenge for scientists. In addition to anthropogenic warming, the ice sheets are influenced by a variety of natural processes, such as variations in snowfall and slow changes in ocean currents.
In climatological terms, nine years are a very short period of observation.
"It would be more prudent to speak of weather rather than climate," Wouters said.
"This `ice sheet weather` can cloak long-term acceleration, or suggest an increase in the depletion of ice mass that could actually be compensated over a longer period", co-author Ingo Sasgen from GFZ said.
"The results highlight the need for a continuous monitoring of the ice sheets with satellites," Sasgen added.
The study is published online in `Nature Geosciences`.