Rising tides: Environmentalist (and Century editor at large) Bill McKibben reports that according to one prediction up to 150 million people worldwide could become “environmental refugees” by the year 2050 because of rising waters. There is evidence “that tropical storms are lasting half again as long, and spinning winds 50 percent more powerful, than just a few decades ago. The only plausible cause: the ever-warmer tropical seas on which these storms thrive” (Newsday, Sept. 14).To our readers: When you access amazon.com from the Century's Web site, the Century earns a percentage of each sale. Thank you!