It is weird to see the rabid environmentalist trashing capitalism, while skirting communism (at least as defined and practiced by any large society on this planet). Some of the true faithful just dont want to wait, so they are trying to destroy what is here (capitalism) in order to force the issue to a quick and rapid conclusion (through dictatorships such as communism).
Others want to speed it up through a dictatorial edict of some sort, while maintaining the appearance of a free society. That part is never really explained other than in their hatred for the capitalistic markets (whereby people choose with their pocketbook instead of a forced compliance to an arbitrary rule).
Man is a short term animal, as you indicated. Most alive today do not remember the way it was because they were either too young or not around. But anyone experiening the "greatness" of the past when all was "idealic" can think back to the old days and see how things are so much better today. Not perfect, but better. You mentioned smelling the lead. Yea, standing behind a running car was always an experience in breath control! But today, (maybe my honker is just kaput), it is barely noticeable (except for diesels).
While the horrors of polution can be seen daily, for the most part they are in nations that have not embraced the fact that polution is self defeating (we can hope they will in time). We have a place here in this state - a big pulp and paper town - that you could smell from 30 miles away back in the 70s. Today? I was out there a couple of years ago, and I could not smell it in town.
We are making progress as we progress (in both living standards and technology), It appears to be working out well, just not in the speed some want. But then their solution is to dismantle the society that is providing the solutions that allow man to progress in a healthy way. And that is just cutting off your nose to spite your face.