National Geographic: Some U.S. states, such as Maine, are already well on their way to meeting new federal targets aimed at curbing emissions of carbon dioxide. But 13 states have been moving in the opposite direction.
While levels of the heat-trapping greenhouse gas went down in 37 states and the District of Columbia between 2000 and 2013, they actually increased in 13 states, according to figures recently released by the Energy Information Administration.
Nebraska saw the biggest rise: Carbon emissions jumped...