The seas are creeping higher as the planet warms. But how high will they go? In Bermuda and the Bahamas, researchers have gone looking for answers; By pinpointing where shorelines stood during a warm period 400,000 years ago, they hope to narrow the range of projections. After correcting for apparent sinking of the islands, the authors of a new study estimate the seas rose 20 to 43 feet higher than today -- far less than previous estimates, but still drastic....