As for austrian economics and externalities, Austrian economics is not a field that ought to answer how we deal with such things. It is merely the study of human action under scarcity. It's not something you decide to adhere to to run your society. It is merely the truth. How we ought to deal with pollution is much more of a politic problem and saifedean simply haven't written on that.

But some austrian did write a few things about this:

“The remedy for air pollution is for the courts to recognize air pollution as an invasive act, and therefore subject to prosecution as a violation of property rights. The remedy is simply to extend the prohibition of aggression to include aggressive assaults against the air and atmosphere.”

— Law, Property Rights, and Air Pollution (1982)

There's probably a lot more that can be found about this.