Population is one of the more heated areas of the sustainability debate. There are those who see population as enemy number one when it comes to the environment. The more of us there are, the greater our ecological impact will be. Unless reined in by deliberate policy, the emerging middle classes of developing countries will eat the planet.
Others say that since population growth is greatest in the poorest countries, consumption is the bigger problem. If one new American will have a bigger environmental impact that 25 Sub-Saharan Africans, surely we should the focus on overconsuming Westerners rather than scapegoating African mothers?
As usual, the truth is more complex than all this, but the nuances tend to get lost in all the value judgements and the long shadow of bad population policies in the past. Another big factor is the misunderstandings around why the population is growing.
Unhelpfully, we often talk about ‘baby booms’ or a ‘population explosion’, which implies a fertility problem. “People are having too many children” is the central theme of most conversations about population. But this is to misrepresent the fundamental reason why populations grow. We’re better off talking about a population transition than population boom. Here’s a useful graph:
The most important thing to notice here is that the increase in population isn’t from people having more children, but from fewer people dying. The world’s population has risen dramatically in recent decades because advances in medicine have prolonged life expectancy, and developments in agriculture have given people healthier and more dependable diets. More people are being born than are dying, and hence the increase. For all its complications, this is a nice problem to have – the alternative is people dying young.
The second thing to note is the downward curve of the birth rate – the top side of the red space in the middle. The natural consequence of a falling death rate is that people choose to have fewer children.
One of the ways in which population theorists have been wrong in the past is that they have been writing in the middle of that red section of the graph. All they see is the upward trend in population numbers, and their extrapolations point to inevitable disaster. In reality, the culture changes as people gain healthcare and sanitation and food security. The next generation will reach child bearing age and will choose to have fewer children than their parents, because they can be more confident that their children will survive into adulthood.
As the end of the graph shows, the end result of the transition is stability again. The population reaches equilibrium, where there are fewer deaths and fewer births. That’s where most developed countries are now, having passed through the transition. Many of the world’s poorest communities are on the other side of the graph – they haven’t yet seen the fall in death rates and we should expect a jump in population in those places.
Population growth occurs in the lag between the fall in the death rate and the fall in the birth rate, so the challenge for us to reduce that red space by as much as possible. That means dramatically accelerating the provision of basic healthcare, clean water and sanitation. It means addressing food security issues, encouraging greater self-sufficiency, and sharing technology and best agricultural practice. It also means slowing the diversion of food into biofuels and meat production. Once people are at liberty to choose smaller families, we need to ensure they are able to do so, and there is a huge unmet need for contraceptives.
Once you understand the process of a demographic transition, the endless claim that “people are having too many children” starts to look simplistic. These are huge cultural shifts that play out across generations. Different countries or regions are at different points along the transition, and need different interventions. And you can’t separate population from the broader narratives of development. There’s also a host of considerations about how you manage a demographic transition, from the youth bulge through to an aging population – but that’s a post in itself.
We need to stop arguing about whether population matters or not – of course it does. And we need to stop arguing about whether it’s a bigger issue than consumption, because that’s to reduce it to abstracts that aren’t relevant on the ground. Most of all, we just need to talk more intelligently about demographics.
- The graph here is from the Royal Society report People and the Planet, which is a useful and balanced analysis of population and consumption. I’ll be writing more about it soon.