Did the Clean Air Act result in a reduction of Carbon Dioxide (CO2) emissions in the United States?

The Clean Air Act primarily targets the regulation of pollutants deemed harmful to public health and the environment, such as sulfur dioxide, nitrogen oxides, and particulate matter. While the Act has had significant success in reducing these pollutants, it does not specifically address carbon dioxide (CO2) emissions, which are not classified as criteria pollutants under the original version of this legislation.

The primary focus regarding CO2 and climate change has shifted to other regulations and proposals, such as the Clean Power Plan and various international agreements, rather than the Clean Air Act itself. Thus, while various actions and programs may contribute to a reduction in CO2 emissions indirectly, the Clean Air Act's framework does not include direct measures for limiting CO2 emissions. This is why the answer is correctly identified as false.