Paris: Warming in the Arctic occurring at twice the global average is on course to up sea levels to 1.6 metres by 2100, a far steeper jump than predicted a few years ago, a consortium of scientists reported on Wednesday.

"Global sea level is projected to rise 0.9 to 1.6 development metres by 2100, and the loss from Arctic glaciers, ice caps and the Greenland Ice Sheet will make a substantial contribution to this," a report by Oslo-based Arctic Monitoring and Assessment Project (AMAP) said.

According to the AMAP, having accounted for 40 per cent of recent rise in ocean levels, the melting snow and ice are likely to play an even larger role in future.

Even the low end of this range would have devastating consequences for coastal cities and densely-populated, low-lying deltas in Bangladesh, Vietnam, China and many other countries, scientists have warned.

Higher seas would literally cover some small island nations, ruin vast expanses of land used to grow food, and boost the intensity of deadly hurricanes and other extreme weather events.

In early 2007, the UN's Intergovernmental Panel on Climate Change (IPCC) said the world's oceans would creep up 18 to 59 centimeters by century's end.

But the panel's landmark report did not include the potential impact of melting ice, especially from the massive Greenland Ice Sheet, which alone holds enough frozen water to
push up sea levels by at least five metres.

The new study shows that the past six years have been the warmest period ever recorded for the Arctic, and that summer temperatures were higher in the past few decades than
at any time in the last 2,000 years.

"The changes that are emerging in the Arctic are very strong, dramatic even," said Mark Serreze, director of the US National Snow and Ice Data Center in Boulder, Colorado, and
a contributor to the report.

The report forecasts that the Arctic Ocean, within three or four decades, will likely become nearly ice free during the summer months.

Three of the last four years have seen polar sea ice shrinking to its smallest area since satellite images became available, with a record low in 2007 of 4.13 million square kilometres.

The report also highlights new evidence that changes in Arctic snow and ice conditions may actually be accelerating the warming process.