The elephant in the room on this issue is population growth - the Earth is simply not capabable of sustaining the current population at a decent (something like our) standard of living. Various religons (i.e Islam, Catholics etc) all encourage population growth (it means more followers)and the result is that we get rising pollution, global warming and food/fuel crisis. Fortunately rising standards of living mean that technologically advanced countries are moving to smaller families but in third world countries (especially in Moslem society) the population grows in an unsustainable fashion.
