WASHINGTON — The rate of ice melting in the Arctic is increasing and a panel of researchers says it sees no natural process that is likely to change that trend.

Within a century the melting could lead to summertime ice-free ocean conditions not seen in the area in a million years, the group said yesterday.

Melting of land-based glaciers could take much longer but could raise the sea levels, potentially affecting coastal regions worldwide.

And changes to the permafrost could undermine buildings, drain water into bogs and release additional carbon into the atmosphere.

"What really makes the Arctic different from the rest of the nonpolar world is the permanent ice in the ground, in the ocean, and on land," said Jonathan Overpeck of the University of Arizona and head of the National Science Foundation's Arctic System Science Committee that issued the report.

"We see all of that ice melting already, and we envision that it will melt back much more dramatically in the future, as we move toward this more permanent ice-free state," he said.

The findings were published in yesterday's issue of Eos, the newspaper of the American Geophysical Union.

The report comes just days after environmental ministers and officials from 23 countries met in Greenland to call on governments to stop arguing over global warming and start acting.

That session was held in the town of Ilulissat, near the edge of the Sermeq Kujalleq glacier that has retreated nearly seven miles since 1960 and has become a symbol of fears that the planet is approaching a dangerous warming.

The researchers said there are two major feedback systems influencing the region — ocean circulation in the North Atlantic and the amount of precipitation and evaporation that takes place.

Feedback can accelerate changes For example, the white sea ice reflects solar radiation back into space, but as the ice melts the dark water will absorb some of the light, warming and melting more ice.

The scientists said they did not see any natural mechanism that could stop the loss of ice.

"I think probably the biggest surprise of the meeting was that no one could envision any interaction between the components that would act naturally to stop the trajectory to the new system," Overpeck said.