The U.S.

For a millennium, the majestic, lily-white polar bear has lorded over the frozen wastes of the Arctic.

Polar bears' designation as a threatened species was challenged in a U.S.

A powerful earthquake rocked one of the few inhabited islands in Alaska's Aleutian chain on Wednesday, but no damage has been found, federal and local officials said.

The National Oceanic and Atmospheric Administration on Monday announced it will provide $250,000 in grants to five states affected by debris from last year’s tsunami in Japan.

U.S.

So far, 2012 has been the warmest year the United States has ever seen, with the warmest spring and the second-warmest May since record-keeping began in 1895, the U.S.

NOAA reported that six other arctic monitoring stations in their international cooperative air sampling network have reported CO2 concentrations of 400 ppm this spring.

Monitoring stations in the Arctic detect record levels of carbon dioxide, higher than ever above 'safe' 350ppm mark

Environmental scientists have known that high levels of the toxic element, mercury, have been accumulating in the Arctic Ocean for some time.