Inexpensive, abundant and relatively clean: EARTH commenter and Stanford geophysicist Mark Zoback makes the case for natural gas to become a key part of U.S. energy policy.

The people of Xuan Wei, China, suffer the world's highest incidence of lung cancer among non-smokers. Burning coal from the Permian-Triassic boundary may be to blame.

Thousands of abandoned coal mines in Pennsylvania have left a legacy: Mine drainage with sky-high metal concentrations is polluting Pennsylvania’s streams and groundwater.

When burned, coal releases more carbon dioxide than any other fossil fuel — but the world's growing demand for electricity means more coal will likely be burned in the near future, not less. Coal-fired power plants that capture their carbon dioxide emissions and permanently store them underground, however, may drastically reduce their impact on the global climate.

Despite all of our efforts to date, no domestic, sustainable, scalable, affordable and environmentally friendly alternative for transportation fuels has emerged. Is it time to give coal-to-liquids a chance?

Don’t think you’re wasting energy? Think again, says filmmaker and one-man energy crusader Jeff Barrie. In the fervently anti-coal and pro-renewable "Kilowatt Ours," Barrie and his camera explain how flipping a light switch could destroy West Virginia mountain-tops.

With oil and natural gas prices soaring, coal’s proponents are calling for more vigorous mining of West Virginia's coal. But mining pollution is also garnering widespread attention.