Emission standards are legal requirements that set the maximum allowable levels of pollutants that can be emitted into the atmosphere from various sources, such as vehicles and industrial facilities. These standards aim to protect public health and the environment by reducing harmful emissions, including carbon monoxide, nitrogen oxides, and particulate matter. Governments and regulatory bodies, like the Environmental Protection Agency (EPA) in the United States, establish these standards based on scientific research and technological capabilities. Compliance with emission standards is crucial for promoting cleaner air and mitigating the effects of climate change, ultimately contributing to a healthier planet for future generations.