For too long population control has been virtually absent from international political discourse. Leaders have been reluctant to raise the issue for several reasons. One is fear of the powerful religious lobbies opposed to contraception. Another is the unfortunate legacy of some over-enthusiastic family planning campaigns in the past, such as India’s in the 1970s.

But several factors are now coming together to put family planning back on the global agenda where it belongs. The most immediate is climate change.