I think the answer is distressingly simple. Without growth, the only way to cure poverty is through sharing. But redistribution is anathema. Without growth to push the hoped-for demographic transition, the only way to cure overpopulation is by population control. A second anathema. And without growth, the only way to increase funds to invest in environmental repair is by reducing current consumption. Anathema number three. Three anathemas and you’re out!

Without growth, how will we build up arsenals to protect democracy (and remaining petroleum reserves)? How will we go to Mars and Saturn and “conquer” space? Where can technical progress come from if not from unintended spin-offs from the military and from space research? Gnostic techno-fantasies of escaping Earth to outer space, partially turning off the sun to make more room for greenhouse gases in the atmosphere, and abolishing disease and death itself feed on the perpetual-growth myth of no limits.

from this post.