The best way to convince the willfully ignorant that something is wrong is to let them live the consequences of it. If they're going to go out of their way to refuse or deny what they are seeing elsewhere, the only thing that will wake them up is a mostly peaceful protestor putting a molotov through their front window. In the long term, this is a guaranteed solution, the consequences will eventually reach them, in a form that even the most determined cannot resist. If its not direct assaults on their persons, homes and cities, it will be the economic consequences of these decisions. In the short term, a lot of people will be caught up in the middle as unwilling collateral, and frankly there's nothing we can really do about it.
The real question is whether they'll drop their ignorance in time to fix anything. By the time their homes are burning, their jobs moved out of the city, and their municipal budget imploding over loss of revenues, it may be too late to save what remains in an area. It'll be dying like Detroit.