There is a lot of talk about reproductive choice in the developing world, and it is extremely important. All human beings have the right to engage in sexual activity on the basis of their free choices and have children only when it is their will to do so. It is an important role of the state to ensure that those rights are not violated.
That being said, there seems to be a disjuncture between concern about rising populations in the developing world and environmental problems. All else being equal, more humans tends to mean more threats to the ecosystems that sustain us. Of course, not all else is equal. People in rich states consume dramatically more resources than those in poor ones. This is true in terms of energy resources (oil, coal, gas, uranium), food resources (especially meat), and climatic impact.
Certainly, we should work to give reproductive control to people (especially women) living in developing states. However, given the concerning destruction of the natural world, does it not make sense to reduce policies that encourage reproduction in rich states? I am not advocating mandatory limits on bearing children. I am simply suggesting that it may be prudent to reduce the degree to which taxpayers in general subsidize those who choose to breed. Even with ample fossil fuels, the world is groaning and straining because of the current human population – especially those who live especially unsustainable lives in rich states. When we reach the point where those fuels are depleted – or when we refrain from using them due to climate concerns – energy intensive lifestyles will become even more unsustainable.
Increasing the cost of children may be an important mechanism for improving the welfare of future generations. No child deserves to live in poverty, but parents who choose to reproduce deserve to bear the great majority of the costs of doing so.