And there’s more urbanization. Even by 2030 Lagos, San Paulo and Delhi will have

And there’s more urbanization. Even by 2030 Lagos, San Paulo and Delhi will have populations above 30 million. To prevent megacities becoming turbulent dystopias will surely be a major challenge to governance. Population growth seems currently under-discussed. That is maybe because doom- laden forecasts in the 1970s, by the Club of Rome, Paul Erlich and others, have proved off the mark. Up till now, food production has more than kept pace — famines stem from wars or mal-distribution, not overall shortage. And it’s deemed by some a taboo subject -- tainted by association with eugenics in the 1920s and 30s, with Indian policies under Indira Gandhi, and more recently with China's hard-line one-child policy. Can the Earth ‘carry’ 9 billion people? There seems no need for gloom or panic on this front... Improved agriculture — low-till, water-conserving, and perhaps involving GM crops could feed that number by mid-century. The buzz-phrase is ‘sustainable intensification’. But lifestyle changes are needed. The world couldn't sustain even its present population if everyone lived like Americans do today— using as much energy and eating as much beef. Population trends beyond 2050 are harder to predict. They will depend on what people as yet unborn decide about the number and spacing of their children. Enhanced education and empowerment of women -- surely a benign priority in itself -- reduces fertility rates. But the demographic transition hasn’t reached parts of India and Sub-Saharan Africa. If families in Africa remain large,, then according to the UN that continent’s population could double again by 2100, to 4 billion, thereby raising the global population to 11 billion. Nigeria alone would by then have as big a population as Europe and North America combined, and almost half of all the world’s children would be in Africa. Optimists remind us that each extra mouth brings also two hands and a brain. Nonetheless the higher the population becomes, the greater will be all pressures on resources, especially if the developing world narrows its gap with the developed world in its per capita consumption. So we must surely hope that the global figure declines rather than rises after 2050. Moreover, if humanity’s collective impact on nature pushes too hard against what Johan Rockstrom calls ‘planetary boundaries’, the resultant ‘ecological shock’ could HOUSE_OVERSIGHT_026733