The continued increase in the use of natural gas for power generation has contributed to 20-year lows in carbon dioxide (CO2) emissions according to a report by the U.S. Energy Information Administration. Between 2007 and 2012, U.S. CO2 emissions decreased 800 million metric tons to 5.3 billion metric tons. Experts estimate that 400 to 500 million tons of the decrease can be attributed to the substitution of natural gas compared to coal-fired generation. The combustion of natural gas produces 44% less CO2, 48% less nitrogen oxide (NOx) and significant reductions in sulfur dioxide (SO2) and mercury. In 2012, natural gas provided 30% of our nation’s electricity, and with air quality standards growing more stringent, this is expected to rise. Greater usage of natural gas will contribute significantly to cleaner power generation, which will result in cleaner air and water.