Heartfield sees environmentalism as a bourgeois movement and he is right. Only those people with the capacity to forego the benefits of industrialization are willing to do so. But it's a trivial critique. Only the bourgeoisie have the *power* to decide the course of industrial development. If one section of the bourgeoisie are pressing another section of the bourgeoisie towards greener development, that's a good thing. Heartfield sees the green movement as anti-development, but what are the chances that, under a capitalist world regime, an anti-development movement will take hold? Capitalists don't make money from anti-development, so far as I can see.
Of course if that development is inevitable (and I think it is) then global warming is also inevitable and even desirable. Humans make smoke and heat and that's not going to change right away. There are also going to be a hell of a lot more humans. The only real, systemic answer is to speed up industrial development in the third world. Only then will there be greater competition for fossil fuels making *relatively* (note that word, Heartfield) wasteful practices like oversized cars too expensive and most green industrial practices require a high level of development.