The thing about overpopulation is that it isn't the birth rate that is causing it. Advances in medicine are raising the mortality age, whereas birth rates are staying relatively steady globally. Now I'm not blaming it on older people, generational conflict is counter revolutionary, but the numbers don't lie. It doesn't have to be a problem, but the concept of overpopulation could very easily be spun to support ecofash ideas, and stuff like he's producing tend to support that idea. Considering the amount of influence Attenborough has in the UK I'd hope you're right about him.