At some point today, you will probably flip on a light switch. That simple action connects you to the oldest and most plentiful source of American electricity: coal. Since the early 1880s — when Edison and Tesla pioneered the distribution of electrical power into our homes — most of that power has come from the process of burning coal. Four years ago, something started to change. First it was slow, and then this past month that change became dramatic. Coal now generates just 34 percent of our electricity, down from about 50 percent just four years ago. Now, the loss of coal as the dominant energy source is having damaging effects on the towns that once relied on the black rock for their livelihood.

Salt is precious in poverty-stricken coastal West Africa, but conservation experts say efforts to extract it are laying waste to mangrove swamps, causing erosion and ravaging fish stocks. In Sierra Leone, one of Africa’s poorest nations still recovering from a 1991-2002 civil war, lawmakers are preparing a bill to join a seven-nation charter to protect the region’s mangrove forests. Conservation group Wetlands International says the initiative is essential for West Africa to save the 800,000 hectares (2 million acres) of mangrove swamps it has left, less than a third of the 3 million hectares it started with.