Have an ocean view or live in a low-lying city? Consider yourself warned. UN researchers are now saying that global sea levels are rising beyond forecasts and over this century will threaten the livelihoods of the 600 million people who live in low-lying areas. Seas could rise by over 3 feet—and that projection doesn't include factors like the polar ice cap melting or ice splintering off. "It looks very benign today but the North Sea can turn into a very ferocious beast," one environmental official said.