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…

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…