Preserving the quality of Earth's atmosphere requires the cooperation of government officials, scientists, and the public. Countries around the world are working together to reduce air pollution.
For example, 197 countries, including the United States, have signed an international treaty called the Montreal Protocol to phase out the use of CFCs. In the United States, the Clean Air Acts sets limits on the amount of certain pollutants that can be released into the air. Some states, such as California, have established their own emissions standards for motor vehicles. At least twelve other states have adopted or plan to adopt standards similar to California's in an attempt to reduce air pollution. Do initiatives like this work? Let's investigate!