Ok, I agree that it is not the most precise language, but the basic message is there. The units of pollution, as you are implying (I think), will change as substances are transformed. For example, sulfur dioxide is formed during combustion and then transformed during scrubbing, so the pollutant has changed, yet there is still a pollutant, of some form, to be dealt with...

I don't see how starting with thermodynamics as a theoretical foundation instead of EKCs leads to "handwaving".

You get a byproduct. It may or may not constitute a form of pollution.

Maybe a better way of saying:

Thermodynamics is an analogy. It's not a law of physics which applies here.

But is the analogy a useful one? Mass may be conserved, but form matters. With you rather have a pound of plutonium or a pound of soot scattered in your backyard? Location and other issues also come into play. If various technologies and policies actually do manage to mitigate the harm from industrial byproducts, what are the added insights from an analogy with thermodynamics? I agree with JoulesBurn's earlier point...there is no scalar measure of pollution that is conserved. The fact that sulfur is scrubbed from emissions does not automatically imply an equally harmful form of pollution somewhere else.

The fact that sulfur is scrubbed from emissions does not automatically imply an equally harmful form of pollution somewhere else.

I acknowledge that very point in the post,

Wealth may allow societies to deal with pollution in a more efficient manner or transform pollution into a less harmful form, but the idea that all nations can become wealthy by consuming the world's resources yet be pollution-free is antithetical to the laws of thermodynamics.

The EKC doesn't imply that society will eventually be pollution free. It only implies that pollution levels will eventually decline. The usual argument is based on environmental quality as a normal good, so as incomes rise people want more of. Brian Copeland and Scott Taylor use production functions that imply an upper bound to pollution abatement in their models.

Edit In economic models, the EKC results from policy intervention (typically a pollution tax). Since full abatement is ruled out, there is always some level of pollution in these models. There is no law of human behaviour that I'm aware of that dictates the response will actually happen.

Copeland, Brian R. and M. Scott Taylor (2003). Trade and the Environment: Theory and Evidence Princeton University Press.

"For example, sulfur dioxide is formed during combustion and then transformed during scrubbing, so the pollutant has changed, yet there is still a pollutant, of some form, to be dealt with..."

You can sell your pollution(gypsum) to ofset some the cost of the FGD system.