Loss of ice in Antarctica caused by a warming ocean may result in rising global sea levels by three metres, warns a recent research.Scientists from the University of Edinburgh in Scotland were able to gauge how levels of ice -- that existed continuously for at least 1.4 million years -- covering the land have changed, the study said. During the previous warm periods, a substantial amount of ice has been lost from the West Antarctic ice sheet by ocean melting, but it may have not melted entirely, the study indicated, suggesting that ice would have been lost from areas below sea level, but not on upland areas."Our findings narrow the margin of uncertainty around the likely impact of the West Antarctic Ice Sheet on sea level-rise. This remains a troubling forecast since all signs suggest the ice from West Antarctica could disappear relatively quickly," said Andrew Hein from the University of Edinburgh in Scotland, Britain.The researchers studied the peaks protruding through ice in the Ellsworth Mountains, on the Atlantic flank of Antarctica, the study revealed in the journal in the Nature Communications. They also assessed the landscape to determine how the West Antarctic ice sheet might respond to increasing global temperatures by measuring changes on slopes at various heights on the mountainside, which indicated levels previously reached by the ice sheet.