I've spent most of my life as a vegan. I don't drive, I've never flown. I have consciously chosen not to procreate. In short, I've tried to actively minimise my negative impact while trying to show by example how we could create a better future. I've come to realise, however, that even if people were willing to change their lifestyles en masse to create a more sustainable society, they would simply continue to fuel the population explosion until they again reached saturation point. As an example, being vegan generally uses only a tenth of the land area of animal agriculture, but even if everyone went vegan I fully expect they would continue to overpopulate exponentially until they again reached the current rate of environmental impact. I suspect the solutions you are talking about would be the same. They might reduce the global ecological footprint of humanity initially, but I don't think we would learn anything from this as a species. Our population would continue to explode until we reached a point once again that was completely unsustainable. I appreciate this sounds negative, but after 55 years I have no faith in humanity to do the right thing. Moving the finish line on our race to self-destruction will not change the ultimate outcome.