From 2010 to 2012, greenhouse gas emissions from power plants fell by more than 10 percent across the nation. The states seeing the largest drops were Washington state, the District of Columbia, Oregon, Massachusetts, Virginia and Maryland. A few states saw increases in greenhouse gas emissions from power plants, with Arkansas and Delaware seeing boosts of nearly 10 percent. Most of the changes in emissions were ultimately due to a drop in natural gas prices, which led to far more electricity coming from natural gas plants than coal-fired plants. Click on a state for more information.