One of most important observations (among many) from the late Hans Roslings’ Factfulness:
When a population is not growing over a long period of time, and the population curve is flat, this must mean that each generation of new parents is the same size as the previous one. For thousands of years up to 1800 the population curve was almost flat. Have you heard people say that humans used to live in balance with nature?
Well, yes, there was a balance. But let’s avoid the rose-tinted glasses. Until 1800, women gave birth to six children on average. So the population should have increased with each generation. Instead, it stayed more or less stable. Remember the child skeletons in the graveyards of the past? On average four of six children died before becoming parents themselves, leaving just two surviving children to parent the next generation. There was a balance. It wasn’t because humans lived in balance with nature. Humans died in balance with nature. It was utterly brutal and tragic.
Today, humanity is once again reaching a balance. The number of parents is no longer increasing. But this balance is dramatically different from the old balance. The new balance is nice: the typical parents have two children, and neither of them dies. For the first time in history, we live in balance. (pp. 87-88)
Demographers refer to this as the Demographic Transition – the move from high fertility and mortality rates to low fertility and mortality rates. A few centuries ago, living standards in some regions began to rise via technology, specialization of labor, and extensive trade. That trend dramatically accelerated about 250 years ago with the Industrial Revolution. Fewer people died young and more people lived to old age, but the fertility rate lagged in its decline. The population explosion of recent generations was due to this lagging decrease in the fertility rate relative to the falling mortality rate.
The Demographic Transition began in Europe but we have seen it repeated in every part of the world in recent generations. The global fertility rate is now below 2.5 children per woman, down from 5.0 fifty years ago, and heading toward “balance” at 2.1 children within about twenty years.* Furthermore, life expectancy at birth in recent generations has risen from about 30 years throughout human history to 72 today – in excess of 80 in some affluent countries.
Every time I reflect on these numbers, I think of Isaiah 66:20, where Isaiah describes the new creation:
Babies in Jerusalem will no longer live only a few days. Old people will not fail to live for a very long time. Those who live to the age of 100 will be thought of as still being young when they die. Those who die before they are 100 will be considered as having been cursed by God.
We are approaching that reality. The world we live in today was positively Utopian until the past generation or two.
We did not get here by being content to die in harmony with nature. We decoupled from nature. We become radically more innovative and productive. The key to future well-being and the welfare of the planet lies in greater decoupling – climate friendly fuels, environment friendly production, more productive agriculture, and the eventual transition to endlessly recycled materials. It must be a world where everyone experiences abundance through their participation in networks of productivity and exchange. That is what "living in balance with nature" truly is.
(Note: At replacement rate fertility, the global population will grow from about 7.7 billion to between nine and eleven billion by century’s end. The children born in 2020 will likely have children at about the replacement rate. However, the population born in 2010 is larger than the coming 2020 population, and the population born in 2000 is larger than 2010’s. If all these age cohorts simply replace themselves in the next few decades, the population will continue grow but at a decelerating rate.)