We'll see what the younger generation does as it ages and some of its members are the "adults of the adults." I hope they can make some changes that older generations have failed to make.
One lesson that may help with optimism and/or hope is how California improved its air quality (smog problems) through various regulations in the late 20th century.
To get a good view of what Los Angeles looked like in 1988, watch the very beginning of this video https://www.youtube.com/watch?v=b1_0373UNDc It's Game 1 of the 1988 World Series, and the camera opens with a view of Dodger Stadium. Yup, that was par for the course in the those days -- and even though L.A. does have some bad air days now, it rarely looks like that.