Coal's share of U.S. electricity generation dropped to its lowest levels in 33 years  between November and December, the U.S. Energy Information Administration (EIA) reports.
In November and December, coal provided less than 40% of the country's power (39%). This is the first time since 1978 that the fossil fuel has provided less than 40% of America's energy for electricity.
According to the EIA, the drop in generation from the black rock is the result of warmer weather and increased natural gas  use. Total electricity consumption was down 7% in December 2011 compared to December 2010.
Despite this, natural gas saw its consumption rise 12% to 86 terawatts between December 2010 and December 2011 On the other hand, coal's generation dipped 21% to 132 terawatts during the same time frame.
For energy providers, coal is still the number one option, however, low prices and the high efficiency rate of combined cycle power plants  is making natural gas more competitive with America's old stalwart energy source.
Coal's competitive advantage in the energy sector looks as though it will continue to decline in near future. New environmental regulations imposed on the industry by the U.S. Environmental Protection Agency has led to a series of power plant closures , as utilities claim it is too expensive to implement the technology required to meet the new standards.