Reporting from Seattle - In what would be the largest habitat zone ever established in the U.S. to protect a species from extinction, the federal government today proposed designating 200,541 square miles on the coast of Alaska as critical habitat for polar bears. Officials said the designation is not likely to further slow the pace of oil and gas development, and it crucially would not impose any controls to slow the biggest threat to polar bears, the melting of sea ice as a result of climate change. Those steps are crucial for polar bears but are being addressed separately in...