It took until 1806 for the population of Earth to reach a billion people. In late 2011, the world population was seven billion. We’re on our way to ten billion by 2100. Fossil fuels drove the exponential surge, forcing us to extract still more in turn and taxing our environment to breaking point. What to do? In the green corner, the Malthusian Left counsels the importance of limits and urge control of population through family planning. In the red corner, free-market Cornucopian right-wingers, augmented by religious fellow travellers, claim that human ingenuity or divine providence will ensure that all ends well. Three new books help to clarify the debate.

‘Ten billion’, a reference to the UN-sanctioned estimate for world population peak, is the hook that Stephen Emmott and Danny Dorling use to bring their contending world-views to life. Emmott’s brief but riveting 10 Billion, based on his critically acclaimed show Ten Billion at the Royal Court Theatre last year, sounds the Malthusian alarm loud and clear. Using a graphic technique that intersperses large-font text with powerful photographs to deliver his message with maximum impact, he walks us through the demographic and economic ascent of man. The result: a relentless increase in carbon dioxide, rising sea levels, mass extinction and melting Arctic ice releasing plumes of methane – the greenhouse equivalent of carbon on speed. He catalogues the litany of failed climate initiatives and technological false dawns and comes to a blunt conclusion: ‘we’re fucked’. Emmott doesn’t duck the population question. In his estimation, ‘the worst thing we can continue to do ... is have children at the current rate’. Pointing to a host of countries stuck at high levels of fertility, such as Niger, he finds religious and political obstacles repeatedly blocking the ‘inevitable’ fertility decline optimists take for granted. This raises the possibility that our numbers will push the planet over the edge. The Green Revolution, the development of new technologies that massively increased agricultural yields in the decades after the Second World War, did not prove Malthus wrong, Emmott insists. It simply purchased our survival for a few decades by off-loading carbon-intensive costs onto the environment. 

Where Emmott is urgent and minimal, Alan Weisman’s Countdown is rich, subtle and elaborate. His magisterial work should be the first port of call for anyone interested in the relationship between population and the environment. Weisman, a journalist, fails to cite the work of most academics in the field of