A volcano near Alaska’s most populous city is showing signs it could be headed toward an eruption, officials said. Mount Spurr, which sits about 75 miles west of Anchorage, has seen “volcanic unrest” ...

There's no other experience on Earth quite like witnessing the northern lights. Also known as the aurora borealis, this spellbinding phenomenon – when brilliant hues of green, yellow, red and purple ...

Global warming is producing a rapid loss of plant species -- according to estimates, roughly 600 plant species have died out since 1750 -- twice the number of animal species lost. But which species ...