GDP is a terrible way to measure economic progress. A post-growth future is about growing things that actually matter: happiness, health and social well-being.
Every day on the TV, belt-way politicians and economists tell us the answer to our problems is more econcomic growth. And yet, a growing number of indictators show that this kind of "progress" isn't progress at all. It's actually killing the planet - and isn't actually measuring the kind of progress that actually matters.
The kind of economic growth they keep talking about simply can't continue on a finite planet with finite resources. We could try to keep our extractive economy going till the ecological web we're a part of starts collapsing - but, I don't think that would end well for us.
It's time we throw this absurd economist logic out the door, understand some basic truths about our relationship to the planet, and start defining progress in a way that makes sense.