Average if expectancy is 80, 80 minus forty is forty.
Air quality has actually been getting steadily better in the areas the world that I live in because of the other companies following the new emissions laws properly. Im confident my diesel truck and RV will allow my family to seek "greener pastures" if needed.
The key is to stay happy with a modest lifestyle. The people that will be screwed are the people with 5000 Sq ft mansons that need $1500 a month in energy just to keep them from being uninhabitable. The neighborhoods in Arizona that won't have water.
If we all do more with less, be kind, and don't complain - we will be fine.
Editing because I can't reply to the awesome comment below. Love it, so true. Statistics changes as you move through space and time. Thank you for this lovely perspective!
Given the amount of unnecessary shite in the air, I'll guess you're about 11 years old and not expecting things to improve much.