The thing is that YES - solving the problem of runaway climate change is dependent on limiting and reducing the population. But NO that doesn't mean adopting a China-style one child policy or running around like crazed eugenicists sterilising anyone without a degree. And it also doesn't mean doing away with child benefit. Because (surprise Peter!) child benefit is not paid to encourage people to have children. It's not a reproduction bribe. Who the hell would decide to raise a child for 18 years in return for £15 a week? It's paid to help parents afford to raise their children well. Once you've fed, clothed, housed, educated and entertained your child you're not necessarily going to have much change left to treat yourself to nights out and designer clothes...
But here's the good news. There are millions of women around the world and right here at home who desperately want to have less or no children, to have children later in life and to control their own fertility. Furthermore some of us crazy feminist types actually think it is their right to do so and to be given access to the tools and education to enable them to make those choices in their own lives. We call them reproductive rights.
Free access to and information about contraception - including condoms which also prevent the spread of HIV and other STDs - and abortion are basic rights that every woman should have. All we have to do is provide them.
Of course it's harder than it sounds. We're not up against "crazy" lefties insisting that benefits be made available to enable parents to afford basics for their children. We're not up against "polite" society's refusal to discuss legislation which would force limits and restrictions on women who wanted to have larger families. We're actually mostly up against religion. Organised religion has worked tirelessly to deny women access to contraception, abortion and even to basic sex education and information about how their bodies work and the options available to them to control their own fertility. Religions benefit from encouraging their adherents to have large families, and this plays straight into a huge patriarchal structure that has attempted for centuries to control women, treat them as breeding factories and keep them in the home raising the next generation of brainwashed disciples.
The planet has much to gain from limiting and reducing the population but the mechanism for this needn't be controlling women's fertility - it can be empowering them to control their own fertility.