Sir John Beddington, scientific adviser to the British government: "If one doesn't intervene in terms of thinking about population regulation now, you're going to be then looking later in the century to major problems."

A Call for Practical Steps on Climate from Britain's Science Adviser - YouTube

At the 2:50 mark, Beddington says "If one doesn't intervene in terms of thinking about population regulation now, you're going to be then looking later in the century to major problems." He then mentions addressing "the problem of human female fertility".