President Donald Trump said the United States "will continue to be the cleanest and most environmentally friendly country on Earth." By some measures, it's the dirtiest.

Robots, tasers and trickery are used in the fight to control fish, snakes, goats and other alien animals that invade and overrun native species.

Scientists have witnessed the first modern case of what they call "river piracy" and they blame global warming.

A new report shows Norway is the happiest country on Earth, Americans are getting sadder, and it takes more than just money to be happy.

The National Science Foundation said the two workers arrived safely late Wednesday in Punta Arenas, the southernmost city in Chile, after a long trip from the Amundsen−Scott station at the South Pole.

Teams working on two continents have marked similar milestones in their respective efforts to tap an energy source key to the fight against climate change: They’ve each produced very impressive magnets.