Some environmental advocates say the federal government is ignoring the real future of solar energy: photovoltaic cells on almost every roof. But even supporters acknowledge rooftop solar isn't the complete answer to the energy question — yet.
Big money, big energy and big environmentalism join forces to support big solar energy projects on federal land in the Southwest. But could these "green" projects actually be anti-environmental boondoggles in the making?
Municipal waste — from poop to heat — can be a valuable resource that could run our cities more cheaply and sustainably, says a hands-on Canadian ecologist.
Millions of people worldwide die every year because of primitive cooking stoves. Around the globe, helpers ranging from Hillary Clinton to African entrepreneurs are making inroads.