Like people at a crowded cocktail party, killer whales raise their voices to be heard in busy waters. This may mean the animals are wearing themselves out to communicate during hunts, new research suggests.

As officials meet in Denmark to prepare for the successor to the Kyoto Protocol, scientists in the Danish territory of Greenland warn of accelerated glacial loss, which could boost sea levels. Video.

A "handsome" three-foot rodent is among the 40 potentially new species found on Mount Bosavi in central Papua New Guinea, one of the least explored places on Earth, conservationists say.

A meat-eating marsupial, a purring frog, and the first new dolphin species in three decades are among at least 1,300 plant and animal species discovered in Australia since 1999, a new report says.

The powerful Category 3 hurricane had quickly strengthened in the Atlantic, but Fred is expected to be short-lived and should stay well away from land, experts say.

Dramatic video shows people trapped on bus and van rooftops as a raging flash flood inundates a busy Istanbul, Turkey, roadway. More than 28 are reported dead in related flooding. Video.

Talk about an urban jungle: Cities store more carbon in their trees, building materials, and dirt than do tropical rain forests, according to "surprising" new research.

Twice the size of Texas, the remote Eastern Pacific Garbage Patch is home to much of the world's plastic trash, and now a scientific expedition has documented the vast "dump" for the first time.

Carbon dioxide isn't the only global warming villain: Animal waste, Arctic "belches", and consumer electronics production are releasing other potent heat-trapping gases, experts say.

In case of emergency, don't break glass, but do launch the space mirrors or flying "volcanoes"—among five risky, globe-spanning Earth-cooling ideas reluctantly recommended for the first time by a major scientific body.

Rock rabbit dung heaps in Africa—some dating back tens of thousands of years—are time capsules of climate and vegetation information. Video.

From wind to sun to cow pies, rural regions are supplying more U.S. farmers with homegrown sources of renewable energy.

Global warming is putting the pika, a hamster-like mammal, in peril. High in the Colorado mountains, a National Geographic researcher is trying to find out why its numbers are falling. Video.

A thousand "humans" melt in Berlin, golfers use a cuddly caddy, fires ravage Los Angeles, and more in our roundup of the week's best news pictures.

Former dolphin trainer Ric O'Barry, star of the new documentary The Cove, again confronts the Japanese town where dolphins are trapped and killed by hand in "drive hunts." Video.