Juhu beach in Mumbai, India, is crowded out with people. Photograph: David Levene for the Guardian

At any public meeting on the environment over the past decade , there’s one question that almost always came up. It is a variation of ‘Why will no one talk about population?’ As a result, population is discussed endlessly while people grumble that no one ever talks about it.

The same oddly circular conversation happened in the Observer Review section in an article relating to the new book, 10 Billion, by Stephen Emmott, head of Microsoft’s Research Lab. Five full pages of extract and interview warned, ‘we’re ignoring … the biggest crisis in human history.’