I agree with that. That’s why degrowth is an attempted response to consumer culture and capitalism. It’s trying to shift cultural norms so that desire to consume is once again bounded. In consumer cultures today, for most people, consumption is essentially boundless–or at least so far beyond the bounds of sustainability to warrant the use of this term. The amount of flying, driving, meat-eating, pet-owning, large home use, unsustainable gadget, and electricity use we continue is so far beyond what the planet can sustain that degrowth of overdeveloped economies like the U.S. is essential.

And while population could also be reined in by cultural forces, it will take intentional effort to do that–something governments and cultural elites are not leading. Hence the U.N’s projection of a population of 9.5 billion people by 2050. Combine that number with a growing global consumer class and climate change and other ecological devastation will drive us toward a massive contraction–as people fight over remaining arable land and retreat from submerging cities. The point of degrowth is to voluntarily contract (in a controlled manner) before climate change pushes us down the nasty path of uncontrolled and unplanned contraction. You could read more about transforming cultures in State of the World 2010, degrowth in chapter 2 of State of the World 2012, or on how to manage the transition in the third section of State of the World 2013. These may be better sources to lean on than the current one you quote.