Start spreading the (bad) news. Even green New Yorkers have a hard time fathoming the effects of climate change on their city, but there’s no way around it: Seas are rising, and Manhattan is an island. They’d better start thinking twice. Klaus Jacob, a German geophysicist and doomsayer, says that New York City will become a “gradual Atlantis.” He’s been studying rising seas for about 15 years and reckons Manhattan could see a six-foot water rise within young New Yorkers’ lifetimes. Though we’re used to catastrophic one-offs like Hurricane Sandy, Jacob says we need to start acknowledging long-term dangers.