Population growth and greater longevity, it is said, are sources of even greater future economic, environmental and developmental problems. Received wisdom has it that rapidly aging populations on the one hand will put intolerable strain on Europe’s social welfare systems. A predicted doubling in Africa’s population, meanwhile, threatens future famine and arrested development on a continental scale. Happily there’s good news baked into the demographic cake that demands we re-examine these assumptions. It should give us all a more upbeat view of the future prospects for most societies.

The gloomier predictions around population growth arise from incomplete analyses of future demographic trends based solely on human numbers. They ignore a vital factor, namely education. A hitherto underappreciated factor in demographic trends, its presence or absence in a population has a huge effect on fertility rates, population size as well as economic, social and technological development. The story of the last few decades has been one of great progress in education globally.

Over the past 40 years, the number of people with secondary or higher education has increased fourfold while the numbers of those without education have remained stable. Education’s importance cannot be underestimated. After 35 years studying these factors it is clear to me that education has multiple benefits, including lower child mortality, lower fertility, better health and higher economic growth in the medium term. Stronger democracies, better human rights and better care of the elderly are other benefits.

This remarkable, unprecedented and heartening trend of investment in global human capital is set to continue. The population educated to secondary or tertiary level globally will double in the next 40 years, while a doubling of the overall population is unlikely.

This trend, more than any other, lies behind the coming global population peak and then decline this century. This process is already underway in Europe. China’s population is likely to decline to its 2000 level during the 2040s and possibly down to half the 2000 level in a century. Globally there is an 80-90% chance the world’s population will start to decline before 2100.

A more educated global population will be healthier, longer lived and enjoy a greater quality of life further into old age due to advances in medical care and the lower levels of old-age disability that come with a more educated populace.

THE WORLD IS GETTING OLDER, FASTER. This is the other big demographic news of the coming century and while it poses challenges it is also a good thing. The world as a whole and countries with low fertility rates in particular face the challenge of an accelerating speed of aging over the coming decades although the trend will slow toward the second half of the century. The median age of the world’s population could increase from 26.6 years in 2000 to 37.3 years in 2050 and then to 45.6 years in 2100 (but there is great uncertainty around future longevity increases). The impact of this will be complex but we must not forget that overall these are positive trends. If we live longer and have a healthier life what is there to complain about?

The association between a more educated population and greenhouse gas emissions is complex. Fewer people could place less pressure on the planet. Educated people tend to emit more because they have higher incomes, but they can also move to new technologies more quickly.

But the more important impact  of education is through strengthening the adaptive capacity to unavoidable climate change. We should ask ourselves: should we spend our climate change adaptation funds educating girls rather than on capital-intensive agriculture? To the Malthusians who despair of an ever more crowded and aging planet, I point to the massive and ongoing investment in future human capital. In the face of dramatic and seemingly unavoidable climate change and greater pressure on resources throughout the next century, I believe this growing pool of human capital will strengthen mankind’s adaptive capacity to meet these new challenges.

Published by PROJECT M in November 2009