That being the case, the defect of the Greens' alleged desire for zero growth which J.H. disparaged is not the zero growth itself, but their omission of specifying the concomitant requirement -- the overthrow or dissolution of the class system and the class war that sustains it.
mbs: On a), I would say that insofar as growth is an expectation of the masses, it becomes a 'need' for psychological reasons and to rulers for political reasons (stability, consent of the governed).
On b), the defect of ZG is the fact that advances in economic justice usually require growth as a context -- since zero- sum disputes are typically resolved in favor of the relatively privileged. "Overthrow or dissolution . . . etc." taken in isolation is just ultimatism, a substitute for politics in the here and now. So this would be the exchange of one form of unreality for another.
mbs