In a landmark decision on climate change and energy, President Barack Obama will announce tough new vehicle gas-mileage standards on Tuesday, the first ever national limits on greenhouse-gas emissions. The new policy, which was worked out between Washington, state governments and the auto industry, will require automakers to meet a minimum fuel-efficiency standard of 35.5 miles a gallon by model year 2016 — four years earlier than Congress currently requires. Not only could the move potentially kick-start the sputtering U.S
