I think Attenborough raises a lot of very pertinent points there. It is kind of taboo to talk about it, but if we are going to discuss climate change we have to be honest and say 'This is clearly a very important part of it' meaning population expansionism. It makes no sense for the biggest energy consumers to have open borders either as it only leads to yet more environmental problems. For me it isn't so much climate change, but general environmental degradation. You see it here too and the population isn't increasing. It is because coal is burned and China's emissions that keep the West supplied with over packaged junk blows over too. It is toxic and some days you cannot go outside. Like with immigration there needs to be a curb in order to stop and evaluate what the heck to do. It is not a game. I might not be interested in over populating the planet, but I do want a sustainable future, so that 2,000 years from now people will still be listening to Morrissey and reading Wilde.