The world's oceans could rise by up to seven meters if Greenland's ice cap entirely melts because of global warming, climate scientists said Tuesday.
Glaciers on Greenland, the world's most icy land mass, are now melting most quickly where they are in contact with surrounding ocean, while ice in the high centre remains intact, said Garry Clarke, a professor at the University of British Columbia in this western Canadian city.
But if global warming causes the freezing level to move higher, the loss of ice would be worse than Greenland experienced in previous interglacial periods dating back hundreds of thousands of years.
"It would be the complete disappearance of the Greenland ice sheet," Clarke told a meeting of scientists and journalists. "We still don't know how quickly our rendezvous with this will occur."
The scientists said much research remains to be done because climate models on Arctic ice sheets are inadequate. Their research contributes to the Intergovernmental Panel on Climate Change, which will release another report in early May.
Much of their data, the scientists said, is obtained by two satellite tracking systems and gravitational physics.
The speakers were from the Canadian Foundation for Climate and Atmospheric Sciences, which is composed of scientists from universities throughout Canada.
Canada will be the country most impacted by global warming, said the group chair Gordon McBean, a scientist and former federal government deputy minister.
But the polar cryosphere -- Arctic ice -- is a focus of the entire international scientific community, said McBean, "because the potential for sea level rise exists primarily in the polar cryosphere."
Shawn Marshall, a geographer from the University of Calgary, said "the state of our knowledge with large ice masses is not up to snuff ... there's a lot of uncertainty in the forecast."
The researchers' work, said Marshall, has a direct impact on predictions of flooding in low-lying countries, and on risk calculations such as how the United Kingdom should rebuild the barrier on the River Thames.
Several of the scientists expressed dismay with the recent announcement by Canada's federal government that Canada will not try to reach the landmark emissions reduction targets set by the international Kyoto accord.
"It's an absolute disgrace," said Richard Peltier, lead investigator with the group and a physicist at the University of Toronto.
The research group's funding is due to run out in 2010, said McBean, and while the scientists have asked Canada's federal government for a commitment for stable future funding, they have been waiting one year for an answer.
"We have no funds to start new initiatives," he told the scientists and reporters.
Asked if international funding agencies will contribute money for the cryosphere research, McBean replied angrily: "Other countries contribute a lot more to international science than Canada does. We claim to be a G8 country, and we should act like one."