California has long led the nation in pioneering clean air regulations, from grappling with smog to setting ambitious zero-emission vehicle mandates. The Golden State's unique authority under the Clean Air Act has allowed it to set emissions standards that exceed federal requirements. Around a dozen other states have followed California's lead.

But that leadership now faces an unprecedented challenge. Last month, Congress voted to revoke three Clean Air Act waivers that the Biden administration had granted California. It was the first time in over sixty years that federal lawmakers blocked any of California's dozens of car and truck rules, and the state quickly responded with a lawsuit.

So what happens next? Can California slash emissions from the transportation sector without this federal support? If not, how can it reach its overall climate goals? And what does this political battle mean for the future of clean transportation—and states' abilities to regulate emissions—nationwide?

This week, Bill Loveless speaks with Mary Nichols about California's role in clean air policy, the impact of losing its vehicle emission waivers, how the auto industry is reacting, and what all of this means for the future of climate action in America.

Mary is a distinguished environmental lawyer and policy expert with over five decades of experience in clean air regulation. She held a number of senior posts in federal and state government, including a long tenure as chair of the California Air Resources Board. She is also a former distinguished visiting fellow at the Center on Global Energy Policy, Columbia SIPA.

Credits: Hosted by Jason Bordoff and Bill Loveless. Produced by Mary Catherine O'Connor, Caroline Pitman, and Kyu Lee. Engineering by Sean Marquand. Stephen Lacey is executive producer.