Mezcal's popularity is booming in the U.S. That comes with a growing environmental cost in Mexico

Thirty years ago, a single light bulb would illuminate the mezcal distillery owned by Gladys Sanchez Garnica's family in rural Oaxaca, where the agave-based spirit was made through the night. As drops dripped from a clay oven, Garnica and her siblings listened to stories told by their parents while neighbors arrived by horse to get a taste of a drink known for its smoky flavor.