LAST year California Solar Systems (CSS), a small installer of residential solar panels, decided to “Buy American”.

In 1868 the world’s first traffic light was installed outside the Houses of Parliament. The gaslit signal controlled the flow of London carriages—at least for a few weeks.

The California environmental agency that probed Volkswagen AG's (VOWG_p.DE) diesel vehicles for violating pollution-control rules is now scrutinizing whether some gasoline-powered vehicles are emit

A wildfire that has forced thousands of Californians to flee their homes exploded in size on Wednesday, threatening a picturesque gold rush town outside Yosemite National Park as dozens of blazes s

California's legislature passed a package of bills that extends the state's signature plan to address climate change by a decade, sending Governor Jerry Brown a cap-and-trade plan that uses market

Not that long ago, the world wondered whether clean energy could survive without lavish government support. Now the question is how far it can spread.

New York State's attorney general and 12 other top state law enforcement officials said on Friday they would mount a vigorous court challenge to any effort to roll back vehicle emission rules by th