The efforts led by liberal David Lawrence and his DemonRAT toadies were a precursor to the business-crippling EPA. Sure, they cleaned up the air a tad but they utterly killed the vitality of the once-thriving steel industry and sent the Western Pennsylvania economy into the ditch for decade upon decade. The exodus from the region still continues because of the misguided actions of these early environmental extremists.
I totally agree just so long as we don’t confuse smog with CO2 which is an odorless, invisible gas. I am not opposed to reasonable efforts to reduce smog. I lived outside Denver for a time. The brown cloud(2nd only to LA’s) there didn’t help people keep their jobs(denver not being a big manufacturing city). It puts a dent Denvers tourist industry.
I know couple from Pittsburgh who are very proud of the improvements in air quality in their home town. They've lived in Massachusetts for the last 50 years, of course. (BTW, my late father-in-law grew up in Johnstown, his wife in Marion, OH. They spent the last 55 years of their lives in Massachusetts as well.)