A solution has to be possible for it to be a viable solution. There is no way the world's population is just going to decide to live an ascetic life suddenly, and there is no world organization nor will to force that to happen. Not only that, but I don't want to live in a world where we have to sacrifice the gains we have made in living conditions just to survive. We need to use our innovative powers to come up with a way we can continue to progress while maintaining the livability of our planet.