90% of the coal mined in the United States was used to generate electricity in 2006.

90% of the coal mined in the United States was used to generate electricity in 2006.

In 2008, the United States depended most on coal to generate electricity. Coal provided approximately 49% of the electricity generated by the United States that year.

In 2008, the United States depended most on coal to generate electricity. Coal provided approximately 49% of the electricity generated by the United States that year.

In 2008, the United States depended most on coal to generate electricity. Coal provided approximately 49% of the electricity generated by the United States that year.

Biofuels contain carbon and although they may burn “cleaner” than oil-derived fuels, they do not avoid generating carbon dioxide emissions.

In 2009, there were no commercial coal-fired plants utilizing carbon capture and sequestration.

In 2009, there were no commercial coal-fired plants utilizing carbon capture and sequestration.

All of the above are emitted by vehicles running on gasoline and diesel fuel.

All of the above are emitted by vehicles running on gasoline and diesel fuel.

All of the above are emitted by vehicles running on gasoline and diesel fuel.

All of the above are emitted by vehicles running on gasoline and diesel fuel.

In 2008, wind accounted for 0.5% of America's energy portfolio.

In 2008, wind accounted for 0.5% of America's energy portfolio.

The energy we capture for use on Earth comes largely from the sun or from nuclear forces local to our own planet.

The energy we capture for use on Earth comes largely from the sun or from nuclear forces local to our own planet.

Out of all the renewable energy sources, biomass contributed the most to U.S. energy consumption in 2008.

Out of all the renewable energy sources, biomass contributed the most to U.S. energy consumption in 2008.

Out of all the renewable energy sources, biomass contributed the most to U.S. energy consumption in 2008.

The United States and Canada are both developed countries. China and India are projected to have the greatest growth in energy consumption between 2006 and 2030.

The United States and Canada are both developed countries. China and India are projected to have the greatest growth in energy consumption between 2006 and 2030.