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.

Since 2000, Indonesian coal production has increased five-fold to meet growing domestic demand for electricity and feed export markets in Asia. The intensive mining is leading to the clearing of rainforest and the pollution of rivers and rice paddies.

After spreading across Pennsylvania, fracking for natural gas has run into government bans in the Delaware River watershed. The basins of the Delaware and nearby Susquehanna River offer a sharp contrast between what happens in places that allow fracking and those that do not.

Many hydroelectric dams produce modest amounts of power yet do enormous damage to rivers and fish populations. Why not take down these aging structures, build solar farms in the drained reservoirs, and restore the natural ecology of the rivers?