ICE could disappear from the Arctic summer within 30 years because of global warming, a US study has found.

As world governments prepare for a summit on the North and South poles that opens tomorrow, research by the University of Washington and the US Government's National Oceanic and Atmospheric Administration has delivered dire forecasts for the Arctic.

Previous studies had warned that ice might vanish by the turn of the century.

But James Overland,

co-author of the study, which was published in the journal Geophysical Research Letters, said "the Arctic is changing faster than anticipated".

The melting has been caused by a combination of natural cycles and human-caused global warming, he said.

The study combined computer projections and observations of ice loss over the past two Arctic summers.

US Secretary of State Hillary Clinton will host government officials and scientists from 47 countries for the summit in Washington to discuss the state of the poles.

In Antarctica tour operators have grave concerns about the size of some of the ships being used and the growing number of tourists in the region. One vessel can carry up to 4000.

Authorities say if a ship that big ran aground it would take four or five days to organise the rescue.