We need to come into the 21st century in how we think about city planning and transit as a starter, and embrace electric vehicles, transit for everyone, and infrastructure for safe biking. With the innovations in ebikes, it's cheap and easy to get around in something other than a car, and the reason most don't is because it's not safe (or they don't feel safe). So let's design our streets so they ARE safe to bike in, and then we'll see a lot more people do it! Less pollution, less traffic, and more exercise. Win-win.
We also need to support more transit. 50% of the pollution in our state is due to vehicles. So make it easy for people to not drive. When we subsidize it, ridership goes way up. That's a good thing, and not just for pollution—it's a great way to help less fortunate people become self-sufficient so they can work and commute even when they can't afford a car.
And yes, I realize our geography is difficult, and we can't fully reduce inversions. But we can certainly make a big improvement.