I think the vitriol hurled at Piketty, Stiglitz, Zucman and Ghosh is completely absurd, but part of the proposal is definitely problematic. My two cents:
1. All our evidence suggests that growth has been the sine qua non of sustained poverty eradication, that is beyond big ‘post-feudal’ redistributions of land and income. For developing countries arguably nothing is more important than brute forcing nominal output growth. But even for advanced economies, long spells of growth stagnation are linked to declining living standards. Italy is a great recent example where pure growth, no matter how chaotic, has proven beneficial.
2. It could well be that comfortably meeting resource sustainability and emissions reduction targets in a timely manner without giving up on growth-led development strictly necessitates convergence on consumption levels that imply a significant reduction for rich counties.
3. This might be compositionally impossible: a managed decline in rich countries could foreclose on development in poorer countries.
4. Even if it is possible, it is very likely that de-growth in the Global North is not just a political non-starter but politically corrosive to any decarbonisation effort and ends up having the opposite intended effect for our emissions path.
To me this just seems intractable. Either side claiming that their path is feasible is misleading either themselves or others.