• 5 Videos, Slides, Films

• 1 Acid rain
• 1 Air quality
• 1 Air quality management
• 1 Automobiles
• 1 Clean Air Act
• 1 Environmental aspects
• 1 Environmental policy
• 1 Exhaust gas
• 1 Greenhouse effect, Atmospheric
• 1 Motors
• 1 Motors (Diesel)
• 1 Pollutants
• 1 Pollution potential
• 1 United States
• 1 United States. Environmental Protection Agency

• 1 Annenberg Learner (Firm)
• 1 Baroff, Beverly
• 1 Begley, Ed, Jr.
• 1 Harvard Environmental Economics Program
• 1 Harvard-Smithsonian Center for Astrophysics
• 1 Harvard-Smithsonian Center for Astrophysics. Science Media Group
• 1 Lewicke, Anna
• 1 Mcelheny, Tobias
• 1 Media & Policy Center Foundation
• 1 Pakenham, George
• 1 Richter Productions
• 1 Richter, Robert, 1929-
• 1 Science Photo Library

• 5 English

• 1 Colorado
• 1 Earth (Planet)
• 1 New York (State)
• 1 United States

• 3 Educational films
• 2 Documentary films
• 1 Short films

Limit year range