Greenie Extinction on the cards?

It came to me the other night. In Australia there are alot of people (indeed the vast majority of voters) fanatically opposed to the carbon tax. The proportion of the population opposed to conservation initiatives could actually grow in numbers rather than shrinking as so many people who identify with being environmentalists are not reproducing! 

Not having babies. We have to do the maths. Will there be any greenie voters coming out of high schools, if the ones who are having the big families are not conservation minded. Are we greenies having such small families condemning ourselves to extinction status, unless behaviour change is sped up (en masse) before our numbers go in to decline? Something to think about. Not being a population control expert, I am putting the thought out there.