It's a matter of when—not if—a massive earthquake will strike Southern California. And the results could be "along the lines of Hurricane Katrina," experts say.

High-tech satellite tags are offering researchers a clearer picture of the feeding and breeding behaviors of the huge but elusive fish, two new papers report.

Photos: Tuna Demand Pressures Wild Stocks

Found only on the Asian island, the animals number only about 15,000 and are threatened by logging, plantations, and human settlements, a new satellite study shows.

See a roundup of the week's news: coal mine collapse in Utah, record-breaking battery-operated car, giant sea bloom, and more.

Though the dynamics are mysterious, sunspots may be linked to heavy rains, flooding, and even outbreaks of bug-borne disease in East Africa, a new study says.

A new model warns that half of the years after 2009 will be warmer than 1998, the hottest year on record.

Soot from American coal burning before 1950 was likely a major contributor to warming the Arctic climate, a new study says.

Unprecedented floods, heat waves, snowstorms, and wildfires have afflicted Earth in the first months of 2007, the UN reports.

A two-month expedition has uncovered a handful of new animal species in a remote forest that has been out of scientific reach for nearly 50 years.

Coral reefs in the Indian and Pacific Oceans have been disappearing much faster and for a longer time than previously thought, a new study shows.

A massive new survey effort found fewer than 1,500 wild tigers—a sharp decline from previous estimates released just five years back.

Plants thought to treat impotence and cancer are disappearing from Uganda's rain forest before scientists can study whether they actually work, experts say.

The world's largest freshwater lake is both shrinking and getting hotter, occurrences that may be related, experts say.

See a roundup of the week's news and events: Bridge over Mississippi River collapses, new Veil Nebula images released, and more.

In a legally symbolic gesture, Russian mini-subs dove under the Arctic ice to try and secure rights to the region's potential natural resources.