From Dougald Hine, What do you do, after you stop pretending?:

‘Changing the world’ has become an anachronism: the world is changing so fast, the best we can do is to become a little more observant, more agile, better able to move with it or to spot the places where a subtle shift may set something on a less-worse course than it was on. And you know, that’s OK – because what makes life worth living was never striving for, let alone reaching, utopias.

There’s a big difference between the task of trying to sustain “civilisation” in its current form … which is what “sustainability” has largely come to mean, and the task of holding open a space for the things which make life worth living. I’d suggest that it’s this second task, in its many forms, which remains, after we’ve given up on false hopes.