The day we became eight billion

The population milestone signals a significant global shift says Professor Andrew Scott


On 15 November 2022, the world’s population is projected to reach 8 billion people, a milestone in human development. This unprecedented growth is due to the gradual increase in human lifespan owing to improvements in public health, nutrition, personal hygiene and medicine. It is also the result of high and persistent levels of fertility in some countries.

While it took the global population 12 years to grow from 7 to 8 billion, it will take approximately 15 years—until 2037— for it to reach 9 billion, a sign that the overall growth rate of the global population is slowing.

London Business School Professor Andrew J Scott and David E. Bloom, a professor at Harvard’s T.H. Chan School of Public Health, have jointly written an article for the New York Daily News on this important milestone. 'Why 8 billion matters: The population milestone signals a significant global shift', (New York Daily News, December 04, 2022) reflects on the fact that this figure is more than double the 1972 headcount, an historically unprecedented half-century of rapid population growth.

But, argue Scott and Bloom, reaching 8 billion souls on the planet signals much more than the achievement of a catchy milestone. “It also marks an important shift in demographic trends. That shift is going to require substantial adjustments for both societies and individuals. Population growth is expected to slow in the years ahead and, in a growing number of countries, populations will decline. The main demographic challenge of the past century has been to support a rapidly growing population.”

The mega challenge ahead is to adjust to dramatic changes in the makeup of that population argue the two academics. Fewer children being born, major shifts in where the world’s population lives and burgeoning numbers of older people will bring massive new health, economic, social and political challenges.

The context of the 8 billion figure is frankly epic. More than 50 millennia passed before global population reached 1 billion. Adding the last billion took only 12 years. Historical increases in the pace of population growth routinely conjure up dark images of mass misery and human suffering, prompted by worries like those articulated by Thomas Malthus, that populations have a natural tendency to grow faster than the resources required for subsistence.

The reality has, however, been different. Over the past five decades, global population has more than doubled — but so too has income per capita, with the share of the world population living in absolute poverty declining from nearly one-half to under one-tenth.

In addition, life expectancy increased by 16 years, infant mortality declined by 70%, and educational enrolment rates increased substantially. These improvements in living standards are the result of human resourcefulness and adaptation — including changes in behaviour, investments in human capital and public goods, policy reforms and institutional and technological innovations.

“Amid all the doom and gloom we hear from every quarter, we should all pause to take in the amazing good-news story this represents: so many more people, and their well-being simultaneously increasing at a rapid clip,” assert the authors.