>> Perhaps a better way of thinking here would be to decrease our pollution FIRST - then come back in 20 years and see how well we did.

I agree and history shows that that approach usually makes sense.
Our cars are a great example. Whether or not the monsters we drove before US laws mandated lower emissions were pollutants, in retrospect it just makes common sense to drive smaller cars and use fewer gallons of gasoline.
My caveat is that we can consider human cost with these mandates.
If we're going to create massive disruptions in the way people earn a living we should weigh that factor in evaluating the desirability of change.