Until recently, little was known about the extent of methane leaking from urban gas distribution pipes and its impact on global warming. But recent advances in detecting this potent greenhouse gas are pushing U.S. states to begin addressing this long-neglected problem.

The Sierra Club has chosen Aaron Mair as its president, the first African-American to lead the largest U.S. environmental organization. In an interview with Yale Environment 360, he talks about the lack of diversity in the environmental movement and what can be done to change that.

Drinking water supplies around the world often contain trace amounts of pharmaceuticals and synthetic compounds that may be harmful to human health. One solution being tried in the U.S. and Europe is to construct man-made wetlands that naturally degrade these contaminants.

The surge in U.S. production of shale gas is leading to the rapid expansion of chemical and manufacturing plants that use the gas as feedstock. But environmentalists worry these new facilities will bring further harm to industrialized regions already bearing a heavy pollution burden.

Yale ecologist David Skelly wanted to know why a sizable percentage of frogs in the northeastern United States suffered from deformities. His ongoing research has implicated human activity — but not in the way many researchers had thought.