A1: The U.S. Clean Air Act and the Science-Policy Interface

In 2020, the U.S. will celebrate the 50th anniversary of the Clean Air Act. This landmark legislation offers a prominent and consequential example of how science and policy have shaped air quality management in the U.S. From acid rain and nitrogen deposition to mercury pollution and carbon standards, connections between scientific research and policymaking have propelled air quality progress in the U.S. over the past four decades, while progress on federal regulations to address climate change has lagged and the fate of mercury policy is uncertain given recent proposals to weaken the Mercury and Air Toxics Standards.

While the details vary from pollutant to pollutant, the science-policy interface in the context of the Clean Air Act can be characterized by six phases: (1) problem identification; (2) skepticism; (3) gradual acceptance of science; (4) debate over solutions; (5) incremental policy-, technology-, and market-driven pollution reduction; (5) monitoring of progress; and (6) periodic evaluation of the need for reforming standards.

In this session, four high-profile science-policy case studies will be presented by scientists who have worked on the front lines of Clean Air Act policy for up to three decades. This session will include case studies on acid rain and nitrogen, mercury pollution, climate and carbon standards, and public health and global air quality. Each presenter will share an account of the scientific breakthroughs that have been vital to policy progress; describe the progress that has been made in addressing these problems as well as new challenges that have emerged in recent years; and outline the implications for achieving policy goals under the Clean Air Act. To round out the session, a fifth panelist will provide the perspective of a senior Capitol Hill staffer and share insights on how science has been helpful to members of Congress in advancing policy under the Clean Air Act.


  • Kathy Fallon Lambert, Senior Advisor, Center for Climate, Health, and Global Environment, Harvard T.H. Chan School of Public Health
  • Charles Driscoll, University Professor, Syracuse University
  • Ellen Kurlansky, Former Policy Analyst, U.S. EPA Office of Air and Radiation
  • Amelia Keyes, Research Associate, Resources for the Future
  • Susan Anenberg, Associate Professor, George Washington University