The Strategic Petroleum Reserve, the world’s largest stockpile of emergency crude oil, has helped shield the United States from energy supply crunches, but debate persists over its management.

Once a fringe movement, green parties are increasingly shaping the debate in countries around the world. How influential are they, and what comes next?

Asia’s major rivers depend on water flows from the Himalayas, and as regional demand continues to grow, a looming water crisis emerges.