Please go here to find an interesting piece by Jonathan Porritt on the links between population and the environment. He makes the very useful point that the environmental movement needs to be brave enough to once again approach the taboo subject of population because in short more mouths to feed equals more environmental pressure. Paul Ehrlich spoke about this subject forty years ago in his very famous book The Population Bomb. My humble opinion is that the problem is not merely a high population it is how that population behaves, even if global measures could be put in place to slow down population growth, the problems would not be solved unless we also change the way in which we behave. As more of the globe is Westernised we, as a global population, are getting more and more materialistic. If this trend was reversed and as a worldwide population we were becoming less materialistic, the environment would be better placed to absorb a predicted 2050 global population of 9 billion.
I think Porritt is the best Environmentalist in the UK today (if not the world) he is brave, consistent and most importantly selfless and realistic. I recommend his book too.