st five years it was at least 1 degree Celsius (1.8 F) above average over the entire Arctic over the entire year, he said.

The new "State of the Arctic" analysis, released by the U.S. government's National Oceanic and Atmospheric Administration, also reports an increase in northward movement of warmer water through the Bering Strait in 2001-2004, which might be a factor in continuing reduction of sea ice.

During that time there were record lows in sea ice coverage in the region, Overland said. This year there was more normal coverage in the Bering area but a record low on the Atlantic side of the Arctic.

In the past when such a shift occurred, there would have been no net loss of ice overall, just a change in where there was a smaller amount, but now there is both the shift and an overall net loss of ice, he said.

Indeed, the report said Arctic sea ice coverage last March was the lowest in winter since measurements by satellite began.

Jacqueline A. Richter-Menge of the Cold Regions Research and Engineering Laboratory in New Hampshire, said the sea ice decline is now being observed in both winter and summer.

The study was designed to assess the overall impact of climate change in the Arctic and will be updated annually. It was compiled by researchers from the United States, Canada France, Germany, Poland, Norway, Sweden and Russia, she said.

In addition, 2007 has been designated the International Year of the Arctic and that will be marked by intense scientific study of the region.

There have been many changes over the Arctic land areas also, said Vladimir E. Romanovsky, a professor at the geophysical institute of the University of Alaska.

These include changes in vegetation, river discharge into the Arctic Ocean, glaciers and permafrost.

The tundra is becoming greener with the growth of more shrubs, he said, which is causing problems in some areas as herds of reindeer migrate.

At the same time, there is some decrease in the greening of the northern forest areas, probably due to drought. The glaciers are continuing to shrink and river discharge into the Arctic Ocean is rising, Romanovsky said.

There has been a significant warming of the permafrost over the last 30 years, he said.

Much of the damage to the permafrost soil can be blamed on human construction activities and fires, he said, but in many areas this frozen ground is close to the melting point and could soon begin to thaw.

Overland said the changes are affecting wildlife in the Arctic, with those living in the middle levels of the ocean, like pollock, seeming to do well, while those on the surface ice or the sea floor, such as walrus or crabs, not coping so well.

"We're seeing a lot of indicators of climate change in the Arctic, and that may be an indicator for change in other parts of the world," he said.

Most of the heating from sun comes to the equator and subequatorial regions, and a lot of heat leaves by radiation from the Arctic, he explained.

"The temperature difference between the Arctic and equator drives all of our weather," Overland said. If the Arctic should warm up and that difference be reduced, weather could change, though people remain unsure what the changes would be.

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