Anyone who was alive before the late 70s knows what real smog was like. In most of the US, we don’t have anything resembling smog. Even in the places we do, it is usually caused by local conditions, mountain valleys, etc.
It’s really frustrating to live in an ozone hotbed because it comes off Lake Michigan from naturally occurring processes certain times of the year.
Back when factories belched smoke and cars had no emissions controls, there was significant benefit to these rules, but tightening them at this point has no real benefit.
We’ll be paying billions to make reductions within the level of sampling error.
...and we take 5 parts per billion out while China is belching thousands of times that every day.
I miss those days.