The head of the Panama Canal Authority, Jorge Quijano, center, opens the main valve to allow water into the flood chambers on the new set of locks on the Atlantic side of the Panama Canal in June 2015. The expansion of the canal, making it wider and deeper to accommodate larger ships, has taken nearly a decade. It opens next month.
San Francisco Bay at sunset, viewed from Oakland, Calif. By the end of the century sea level could rise by five feet because of global warming, according to climate scientists, flooding much of the bay's coastal infrastructure.
Marcio Jose Sanchez/AP