Washington Post: While the nation debates the cost of climate change — whether the price of electricity and gasoline should increase because of their greenhouse gas emissions — the problem already has a price tag on the Chesapeake Bay. Sea levels are rising almost twice as fast in the Chesapeake region as in most of the world, and waterside communities are spending millions to keep the water from eroding yards, marshes and sandy beaches. The area’s beaches are dealing with the same bad luck: …