A grizzly took down a moose in a driveway, a fire raged in L.A.'s famed Griffith Park, and 20,000 naked people bared all at a public photo session in México City.

A new NASA study predicts that global warming could make 100-plus-degree Fahrenheit summer days common in the eastern United States.

The giant blaze is just the latest to strike the park as drought grips southern California. Learn about the fire's causes and hear what experts say its effects will be.

New imaging of the deep Earth reveals sinking slabs of material underneath the continental U.S. may explain the mystery of Midwestern earthquakes, which include a 1812 temblor in New Madrid, Missouri.

Biofuels such as ethanol have great potential to mitigate human-caused global warming—but could also boost food prices and lead to rampant deforestation, the UN says.

Scientists announced plans today to put descriptions, pictures, audio, and video of all the world's 1.8 million known life-forms on the Internet for free.

The deadly twister that hit Kansas Friday was rated a powerful F5. But what do tornado ratings mean, and how are these killers tracked?

It took a rare collision of conditions to spawn the "incredible" tornado that flattened Greensburg, weather experts say.

A massive flood in 1607 that remains Britain's deadliest natural disaster was actually a tsunami, a new study says, and a similar killer wave could strike the U.K. again.

A hurricane even weaker than Katrina could devastate the Louisiana city, despite repairs by the U.S. Army Corps of Engineers, experts say.

After spending weeks adrift at sea, butterflyfish head back to the same reefs their parents inhabit, a surprising discovery that could affect how marine reserves are established.

Babies brawled at a Tokyo bawl-off, NASA spied Jupiter's other spot, and camels showed off their curves and long legs this week.

An international team of scientists and policymakers says that global warming can be halted if the use of fossil fuels is curbed considerably in the coming decades.

The African island country has created 15 new protected regions to help save its famed and diverse lemurs and other wildlife.

Virtually eradicated in the 1990s, water hyacinth has made a comeback in East Africa spurred by pollution and drought.