1- There is an absolute physical and ecological limit to economic growth.
2- We are rapidly approaching that limit.
3- We must stop economic growth before we reach that limit. Otherwise, human well-being will fall precipitously.
4- Rich nations should establish the steady state economy right now, while the poorer nations should, for humanitarian reasons, increase their wealth for the time being.
A post by Will Wilkinson has some bearing on proposition 4:
As the world grows increasingly globally interconnected, you have to squarely face the fact that slowing growth in the big economies really, really hurts poor people elsewhere. This is not dogma. It's what you might call "reality based," or the truth. And that's one of the main reasons I find it despicable when comfortable western intellectuals argume to the effect that England, say, ought to impose policies meant to get their citizens to work less and enjoy more leisure time, since the added wealth created by their economic production isn't doing THEM as much good as longer vacations would. But policies that effect the productivity of the English economy don't just effect the English. Lower growth in England means more hungry, sick and dying babies in China. That's why growth-slowing "quality of life" reforms in advanced economies can be construed as "progressive" only relative to a repugnant nationalist, anti-cosmopolitan standard.In case anyone is worried, I also note that the empirical support for proposition 2 is very weak.