The area covered by sea ice in the Arctic has shrunk to its lowest level this week since satellite measurements began nearly 30 years ago, opening up the Northwest Passage – a long-sought short cut between Europe and Asia that has been historically impassable.

The area covered by sea ice in the Arctic has shrunk to its lowest level this week since satellite measurements began nearly 30 years ago, opening up the Northwest Passage – a long-sought short cut between Europe and Asia that has been historically impassable.

Corals in the central and western Pacific ocean are dying faster than previously thought, University of North Carolina at Chapel Hill researchers have found. Nearly 600 square miles of reef have disappeared per year since the late 1960s, twice the rate of rainforest loss.

Warmer sea temperatures are linked to the severity of a coral disease, according to a study on Australia's Great Barrier Reef that offers a dire warning about global warming's potential impact on the world's troubled reefs.