In a world where we think of climate change and national debt as Western worries, Asia's dirtiness is enough of an absolute eco-hazard to warrant its own kind of debt if the rest of us thought the same way.
Well. In some way classes exist. People in some of them don't bother the smog around them, they'll just walk in masks. They also get paid less. People in other ones do. They want cleaner air, good wages, plenty of affordable goods produced by the former group for its smaller wages with all the pollution.
When I talk things about how computers of 1999 were good enough, I mean that among other things.