The melting of mountain glaciers and ice caps as a result of global warming over the next century is likely to cause bigger than expected increases in sea levels, according to scientists.
An assessment of the volume of water running into the oceans from melting ice caps suggests that sea levels could rise by two to three times the amount previously expected.
The study used satellite monitoring to assess the contribution to sea levels made by all land-based ice, except for the two continental-sized ice sheets of Greenland and Antarctica.
It found that the volume of water melting into the sea each year from glaciers and ice caps was 100 cubic miles (417 cubic km), which is almost equal in size to the amount of water in Lake Erie. However, this volume of meltwater is increasing by a further three cubic miles each year because of an acceleration in the rate at which ice caps and glaciers are melting, said Professor Mark Meier, of the University of Colorado.
“One reason for doing this study is the widely held view that the Greenland and Antarctic ice sheets will be the principal cause of sea-level rise,” Professor Meier said. “But we show that it is the glaciers and ice caps, not the two large ice sheets, that will be the big players in the sea rise for at least the next few generations.”