Washington: World`s shrinking glaciers contributed to almost a third of the sea-level rise between 2003 and 2009, a new study has found.
While 99 per cent of Earth`s land ice is locked up in the Greenland and Antarctic ice sheets, the remaining ice in the world`s glaciers contributed just as much to sea rise as the two ice sheets combined from 2003 to 2009, researchers say.
The new research found that all glacial regions lost mass from 2003 to 2009, with the biggest ice losses occurring in Arctic Canada, Alaska, coastal Greenland, the southern Andes and the Himalayas.
The glaciers outside of the Greenland and Antarctic sheets lost an average of roughly 260 billion metric tons of ice annually during the study period, causing the oceans to rise 0.03 inches, or about 0.7 millimetres per year.
The study compared traditional ground measurements to satellite data from NASA`s Ice, Cloud and Land Elevation Satellite, or ICESat, and the Gravity Recovery and Climate Experiment, or GRACE, missions to estimate ice loss for glaciers in all regions of the planet.
"For the first time, we`ve been able to very precisely constrain how much these glaciers as a whole are contributing to sea rise," said geography Assistant Professor Alex Gardner of Clark University in Worcester, lead study author.
"These smaller ice bodies are currently losing about as much mass as the ice sheets," Gardner said.
"Because the global glacier ice mass is relatively small in comparison with the huge ice sheets covering Greenland and Antarctica, people tend to not worry about it," said CU-Boulder Professor Tad Pfeffer, a study co-author.
"But it`s like a little bucket with a huge hole in the bottom: it may not last for very long, just a century or two, but while there`s ice in those glaciers, it`s a major contributor to sea level rise," said Pfeffer, a glaciologist at CU-Boulder`s Institute of Arctic and Alpine Research.
Current estimates predict if all the glaciers in the world were to melt, they would raise sea level by about two feet. In contrast, an entire Greenland ice sheet melt would raise sea levels by about 20 feet, while if Antarctica lost its ice cover, sea levels would rise nearly 200 feet.