Apparently there's some confusion out there in environmentalland about the environmental Kuznets Curve. All it is, really, is an observation that the environment is a luxury good. By this we do not, at all, mean that nothing need be done about it. Quite the contrary, we mean that only richer societies are going to do anything about it. Thus this is simply nonsense:
Pinker suggests that the environmental impact of nations follows the same trajectory, claiming that the “environmental Kuznets Curve” shows they become cleaner as they get richer. To support this point, he compares Nordic countries with Afghanistan and Bangladesh. It is true that they do better on indicators such as air and water quality, as long as you disregard their impacts overseas. But when you look at the whole picture, including carbon emissions, you discover the opposite. The ecological footprints of Afghanistan and Bangladesh (namely the area required to provide the resources they use) are, respectively, 0.9 and 0.7 hectares per person. Norway’s is 5.8, Sweden’s is 6.5 and Finland, that paragon of environmental virtue, comes in at 6.7.
Pinker seems unaware of the controversies surrounding the Kuznets Curve, and the large body of data that appears to undermine it.
Sadly, such is the state of economic knowledge out there that we've even got to step back and explain what a luxury or superior good is. It doesn't mean something which is better, nor has it the colloquial or vernacular implications of luxury, something only for the rich and leisured.
An inferior good is something we spend less of our income upon as our incomes rise - potatoes, say. A normal good is something we spend the same portion upon, a luxury something we spend a higher portion of those rising incomes on. Just about everything is any and all of the three at some income level.
That environmental Kuznets Curve doesn't say, necessarily at least, that a richer society will be a cleaner one. What it does say is that after a certain level of income (wealth, if you prefer) then a society will spend a rising portion of that increasing income on a clean environment. It refers not to what absolutely will happen but to the economic capability of what resources will be devoted.
Once that is understood then the arguments against it disappear. We still get to have those lovely arguments about what should be done, which is the most important thing we should devote those resources to. We are, just as with GDP itself, just making an observation about the economic resources available. How they're deployed is another matter.
That's also where it all gets interesting of course, we ourselves arguing that a cleaner environment is indeed something worthwhile - because everyone else seems to think so, the true determinant - which is why we must be efficient in our deployment of those resources in cleaning it all up. Rather than killing off the industrial capitalism which provides the resources to do the cleaning....