The US Energy Information Administration (EIA) has released data proving that the Clean Air Act regulations have had a tremendous impact and are hugely successful at reducing pollutants and greenhouse gases.
In 1990, the Clean Air Act was amended to combat ozone depletion, acid rain, and to combat 189 toxic pollutants, sulfur dioxide (SO2) and nitrogen oxides (NOx). As a result, the US power industry’s emissions have steadily declined.
These data demonstrate that emissions have declined at such a rate that 2012 was the lowest year since 1990.
Pre-2007, much of the reduction was the result of coal plants implementing solutions to reduce emissions and was not due to overall coal usage reduction.
However, most recently, the decreased use of coal for electric power generation, due in part to the prevalence of natural gas, has reduced SO2 and NOx emissions considerably.
The success of the Clean Air Act in the US is proof that countries with immense air quality problems, like China, Korea, and Iran, could benefit greatly by making stricter air quality policy improvements.
 has released data proving that the Clean Air Act regulations have had a tremendous impact on the environment.){kind=link}