natural gas

For decades, coal was king of electricity generation in the U.S., but that's changing. Across the country, coal power plants are being replaced with generators that run on cleaner burning natural gas.

A well on the outskirts of LA has been spewing natural gas into the air for months. Once it's sealed off, regulators say, it can never be tapped again. Other new restrictions are also being imposed.

Since October, a natural gas storage well near Los Angeles has been spewing hundreds of tons of methane gas each day. The leak isn't expected to be fixed for months.

Montana has one of the heaviest lifts of any state to comply with the EPA's plan to reduce carbon emissions. But the state is also rich in renewable energy, and the regulations may be a boon to some.

Driven by new regulations and fracking, more coal power plants are retiring for cheaper, cleaner-burning natural gas. But scientists have yet to work out the fossil fuel's imperfect climate footprint.

New York state has banned fracking, but it is considering a plan to allow fracked gas to be stored under Seneca Lake — which isn't sitting well with residents of the state's Finger Lakes region.