Earth Matters

11 of the most endangered trees in America

Can artificial insemination save the Mexican wolf from extinction?

Obama's national monuments are a big deal

8 species on life support

Why are fireflies disappearing?

5 surprising facts about roadrunners

Striking mother-of-pearl clouds may have inspired 'The Scream'

Mom? … Anybody? Adorable bear cub needs a hand with clingy scallop

Town bids farewell to 600-year-old oak

Houston, we have a space debris problem

Common caterpillar found to eat plastic shopping bags

The case for transforming Californian gridlock into a green energy source