Republican Sen. John McCain of Arizona and Democrat Hillary Clinton of New York told reporters in Anchorage that Inupiat Eskimo residents in Barrow, Alaska, have found their ancestral land and traditional lifestyle disrupted by disappearing sea ice, thawing permafrost, increased coastal erosion and changes to wildlife habitat.

Heat-stimulated beetle infestation has also killed vast amounts of the spruce forest in the Yukon Territory, they said.

Such observations provide more ammunition in the fight for a bill, co-sponsored by McCain and Connecticut Democrat Joe Lieberman, to cap US greenhouse gas emissions, McCain said. That bill has repeatedly failed to pass the Senate.

"People around the country are going to demand it," McCain said. "It's the special interests versus the people's interest."

The United States is the biggest emitter of heat-trapping carbon dioxide, which many scientists have linked to global warming.

Oklahoma Republican Sen. James Inhofe, chairman of the Senate Environment and Public Works Committee, has dismissed global warming as a hoax and questioned scientific evidence supporting rising temperatures.

The White House has warned that mandatory caps on greenhouse gas emissions could stunt US economic growth. President George W. Bush supports a voluntary plan for industry to cut greenhouse gas output.

The senators said they were headed Tuesday for a visit to Kenai Fjords National Park in Seward, where the National Park Service has been tracking retreating glaciers.