I thought the historical motivation was just that there was not much of a concept of pollution harming people far away, so this sort of activity has traditionally been allowed by default. For thousands of years, you could burn your wood on your land and everybody was fine with that. At most you might have some trouble with your neighbors if they don't like your smoke. But the idea you'd cause diffuse harm to millions is pretty new, and has a lot of inertia to overcome.
This is actually incorrect. When I was digging through old new york times articles from the 1900s and 1930s (using the online search) I stumbled across numerous articles expressing concern about the pollutants being released by factories and combustion-engine automobiles, and how they not only affect the immediate area but surrounding towns. Don't have links to the sources at the moment, or the time right now to pull it up, will check back later, but if you search on nytimes.com you should be able to pull them up.
I'm thinking an order of magnitude or two farther back. Humanity spent thousands of years making fires, but widespread awareness of how the pollution it emits can hurt people is only a century or two old.
Yes, certsinly that also. DI meant in the context of the more recent past as the source of pollution was moved out of the city centre people probably lost interest in pollution as it affected them less directly. Prior to that people were either too sparsely populated to be affected or there was no alternative.
Or something. I guess I speculating given there's other factors I'm not taking into account like automobile emissions and the advent of emissions standards due to air quality concerns.
