The document discusses a court case brought by the State of Massachusetts against the Environmental Protection Agency (EPA) demanding that the agency enforce the Clean Air Act. Specifically, the state wants the EPA to limit carbon dioxide emissions from power plants and car companies. While the EPA is concerned about the economic implications, many scientists have presented evidence that carbon dioxide emissions are contributing to global warming and climate change. The document argues that the EPA has a moral obligation to regulate CO2 emissions from automobiles as enforcing the Clean Air Act could mean fewer deaths and health issues from dirty air.