I agree with many of your points Tessa, what you haven't mentioned is that we need to find a way to reduce the rate of global population growth - as a collective of now almost 8 Billion people, we are putting an enormous strain on planet's resources. I don't see this point addressed much, but it's at the core of this issue. With each 'new' person we'll need more houses, more cars, more clothes, more electronics, food etc. etc.