Scientific American: Thomas Abdallah has seen a lot of water in his 26 years of work for New York City's transit system. In December 1992 a nor'easter storm killed the subway's power, forcing rescue crews to evacuate passengers from flooding tunnels. In August 2007 a five-inch deluge that meteorologists called an extreme climate event shut down the system again. So did Hurricane Irene in August 2011. Then came Hurricane Sandy.
As Sandy's storm surge began to flood downtown Manhattan last October, dozens of New York...