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.

A type of acacia tree could serve as a free—and less polluting—source of long-lasting and crop-boosting nitrogen, experts say.

The North Pole is warmer now than it has been in the past 2,000 years, a trend that is holding off the next ice age, according to the most extensive study yet on Arctic climate change.

Living apart from the natives, the first farmers in Europe were skilled immigrants from far-off farming cultures, a new study says.

Over the past 30 years key species have declined by 40 percent both inside and outside the reserves, according to a new study that questions a central tenet of Kenya's wildlife conservation strategy.

Low water levels at a southern Mexico reservoir have revealed the remains of a 16th-century convent submerged when the lake was created 40 years ago. Video.

See undersea worlds that stand to be lost—and that six Southeast Asian governments are trying to save with their new Coral Triangle initiative to protect coastal reefs. Video.