A Warmer World

Sustainability
A giant mushroom cloud of steam and ash explodes out of the Mount Pinatubo volcano in the Philippines in 1991.
Arlan Naeg/AFP/Getty Images
Sustainability
Dennis M. Bushnell
NASA
Sustainability
Carl Hodges holds a salicornia plant. Salicornia packs as much high-quality vegetable oil per acre as soybeans, making it an ideal biofuel crop.
Sam Eaton