Preserving biodiversity in rich habitats is good. But global warming and other new threats may call for a new strategy
Water is needed to generate energy. Energy is needed to deliver water. Both resources are limiting the other—and both may be running short. Is there a way out?
Former CIA director, R. James Woolsey, says America's oil dependence is a grave threat
Cultivating crops in downtown skyscrapers might save bushels of energy and provide city dwellers with distinctively fresh food
Massive developments proposed for the U.S., China and Abu Dhabi aim to reduce or even eliminate the environmental cost of city living