Emission standards are regulations set by governments to limit the amount of pollutants that can be released into the air by vehicles, factories, and other sources. These standards help protect the environment and public health by ensuring that harmful substances, like carbon monoxide and nitrogen oxides, are kept at safe levels. By enforcing emission standards, countries aim to reduce air pollution and combat climate change. For example, the Environmental Protection Agency (EPA) in the United States establishes these limits for various industries, encouraging the development of cleaner technologies and promoting sustainable practices to improve air quality.