California has made tremendous progress on air pollution during the last few decades, but still faces two major air quality challenges. Parts of the San Joaquin Valley and South Coast exceed federal standards for ozone and particulate matter by a large margin. Both areas are in danger of missing federal deadlines for meeting air pollution standards.
California can meet these challenges. Unfortunately, California lawmakers and regulators have often pursued unneces-sarily expensive and even counterproductive policies, while failing to exploit cost-effective pollution reduction opportunities. This brieﬁng paper summarizes the air pollution situation in the San Joaquin Valley (SJV) and South Coast (SC), recommends policies for achieving cleaner air more quickly and more cheaply than current policies, and assesses the political viability of the recommended approaches.