America’s top CLIMATE COP

Mary Nichols can take some pride in the view as she travels out of Los Angeles. The San Gabriel Mountains rise up to the north, framed by blue sky with just a touch of midday haze. The clear vista comes in large part because of the California Air Resources Board (CARB), the agency that Nichols leads, which has spent decades cleaning up the city’s air. Now she and her team are setting their sights even higher — with an ambitious plan to cut California’s greenhouse-gas emissions.

With an economy that outranks all but eight countries, California is a political and economic heavyweight that has never been afraid to flex its muscles. It is big enough make an impact, and now that politicians in Washington DC have abandoned attempts to enact a national climate law, California is forging ahead on its own. Nichols feels the burden of that strategy acutely, and she is well aware of the challenges ahead.