A crucial quote from Mike Davis:

The paramount question is not whether the population has grown too large, but: how do you square the circle between, on the one hand, social justice with some kind of equitable right to a decent standard of living, and, on the other, environmental sustainability? There aren’t too many people in the world – but there is, obviously, over-consumption of non-renewable resources on a planetary scale. Of course, the way to square that circle – the solution to the problem – is the city itself. Cities that are truly urban are the most environmentally efficient systems that we have ever created for living together and working with nature. The particular genius of the city is its ability to provide high standards of living through public luxury and public space, and to satisfy needs that can never be meet by the suburban private consumption model.