Environment

California regulators voted to reduce financial incentives for people considering rooftop solar. Climate activists worry that this will undercut greater adoption of solar in the state--and nationwide.

For years, powerful farmers in California's Central Valley fought for more water from the state's rivers. Now some are changing course, because there's no more water to be found.

A giant laser facility in Livermore, Calif., says it has created net energy from nuclear fusion. It's an important breakthrough, but fusion power remains a distant dream.