MPBN: Over the next six years, Mainers and other motorists around the Northeast can expect to be filling up their gas tanks with gas that is increasingly derived from Canadian tar sands oil. That's according to a new report from the Natural Resources Defense Council, which says the carbon intensive extraction and refining process for tar sands runs counter to many states' plans to cut carbon pollution, the major driver of climate change. Susan Sharon has more. According to the report, extracting and refining...