As time goes by, I notice that people's general view of the world seems to be changing in a more "Green" direction.
That is, protecting nature and the planet seems to have become for the left and right, a sacred duty. It is tied to issues such as regulation and job creation under depressions as well as trade and globalization. Supporting it seems to be a utilitarian argument for animal rights, skeptical postmodernism, and a general distrust of capitalism. But above all it seems to be supported by popular christianity and popular religion in general which is how it ("Greenism") has become such a popular meme. This idea I would guess, will play a major role in the 21st century -it has all the justifications for things like wars for natural resources as well as increased regimentation of the economy.
The left wing would support the enviromental ideology to further its traditionally "socialist" aims while the right wing would support the enviormental ideology to further its traditionally "imperialist" ones.
Is there any other ideology that could lay hold of the popular imagination as against enviromentalism? I don't think so -racism lost its viability decades ago, libertarianism is too radical to be consolidated into the popular mind, and religion is too vague a value to be considered a force all its own in political thought.
But there is a way that enviro-mercantilism can collapse and this is if it eventually looses the institutional struggle. One way that it could do this is if the third world somehow defeats or somehow outcompetes the first world -that would probably ring the death-nell of enviro-mercantilism. Would this happen? I don't know.