Hundreds of millions of Americans are presently besieged by a massive arctic blast and winter storm. Luckily for them, it will only be temporary. That wasn't the case 20,000 years ago... Between ...

Koalas with the bodies of lions. Elephants the size of your dog. Gigantic, 8-foot-tall sloths. These aren’t creatures found in science fiction: They walked our planet a million years ago, during the ...

Earth’s path around the Sun is not a fixed racetrack but a slowly shifting orbit, and those subtle changes have a long history of reshaping the planet’s climate. As astronomers refine how these ...

Scientists have uncovered a missing feedback in Earth’s carbon cycle that could cause global warming to overshoot into an ice age. As the planet warms, nutrient-rich runoff fuels plankton blooms that ...