Climate change is expected to cause sea levels to rise -- at least in some parts of the world. Elsewhere, the level of the ocean will actually fall. Scientists are trying to get a better picture of the complex phenomenon, which also depends on a host of natural factors. When presented as a globe, the Earth looks as round and smooth as a billiard ball. To anyone standing on a beach, the ocean looks as flat as a pancake. But perception is deceptive. "In reality, the water in the oceans wobbles all over the place," says oceanographer Detlef Stammer. He...