Chinese beachgoers walk by an algae-covered public beach in Qingdao, China, in July. The seas off China have been hit by their largest-ever growth of algae, ocean officials say, with waves of green growth washing onto the shores. AFP/Getty Images hide caption

The New York City skyline is mostly dark in this photo of the 2003 blackout that hit U.S. and Canadian cities. Frank Franklin II/AP hide caption

The band Canzoniere Grecanico Salentino is leading the revival of an old Italian folk style called taranta, which has hypnotic rhythms meant to have restorative powers. Daniela Cardone/Courtesy of the artist hide caption