Science & Technology

Improving World Health Will Reduce Overpopulation, Not Make It Worse

It's not the nicest thought but chances are you've had it: On a planet with limited resources and too many people, won't helping more people live longer make those resource problems worse? We have good news: The answer is no. In fact, the opposite is true. According to experts, making people healthier and wealthier the world over will actually ease the overpopulation crisis. Here's why.

The Prince and the Paupers

To understand the dynamics at play here, let's go back to England in the 1600s. Unless you were one of the noble few with the majority of the country's wealth, you were most likely a peasant who lived on the same plot of land as the generations before you, spending your days farming the same crops and eating the same meager meals. Most peasants lived at subsistence level, with no safety net to save them if the worst happened, and a quarter of England's population lived in a permanent state of poverty. That's roughly the poverty rate of modern-day Nicaragua. During that time, the death rate was so high that families had to have lots of children to increase the chances that a few would survive.

Then, the industrial revolution happened. Advances in science, medicine, and technology led to increases in health and a reduction in poverty — and fewer people died as a result. In 1681, the death rate in England and Wales was 35 per 1,000 people. By 1800, it was around 25 and falling. But families hadn't quite gotten the memo. Even though they had more food, greater wealth, and healthier children, they kept having kids the way they had when death was at their doorstep. In the mid-1600s, the birth rate hovered around 25–30 per 1,000. It hit an all-time high of 42 in 1816. With less death and more babies, the population of England exploded from around 6 million in 1750 to nearly 17 million in 1851. That figure had nearly doubled again to 30 million by 1901.

But then, things slowed down. Now that children were surviving into adulthood, the birth rate dropped. The death rate plateaued. The population of England in 2001 was 49 million — quite a bit more than it was a century before but nowhere near the growth rate that once was.

There are parallels in other countries. According to Our World in Data, the U.S., France, and Norway hit this plateau in the 1970s. Israel hit it in the 1990s. The population phenomenon England experienced is predictable and well documented. It even has a name: the Demographic Transition Model.

All The World's a Stage

The Demographic Transition Model has five stages:

  • Stage 1: Both birth rates and death rates are high, and population stays pretty consistent. This applied to most of the world before the Industrial Revolution.
  • Stage 2: Advancements in medicine lowers death rates, but birth rates remain high. That leads to a rapid growth in population. This applies to many of the world's least developed countries.
  • Stage 3: Birth rates gradually decrease with increases in wealth, women's status, and contraception access. This applies to most developing countries today.
  • Stage 4: Birth and death rates both plateau at a low rate and the population stabilizes. These countries tend to have better economies, healthcare, and levels of education. Most developed countries are in this stage.
  • Stage 5: This theoretical stage is when births fall below the rate needed to make up for the death rate, and the elderly outnumber the young. No country has reached this stage, but experts fear some are close.

Throughout this model, as conditions improve, population growth slows. And importantly, this doesn't always happen on the same timeline; according to Kurzgesagt, what took England hundreds of years took Malaysia and South Africa 34 years, Bangladesh 20 years, and Iran just a decade. As more countries reach stage 4, more people will have the education to advance science and technology, and that benefits the entire world. Transitioning through these various stages at different rates will certainly lead to growing pains, but if we work to lift all boats with the rising tide of nutrition, medicine, and economic growth, we could see a promising future.

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It's clear that improving global health will help the world as a whole. In "To Repair the World: Paul Farmer Speaks to the Next Generation," doctor and social activist Paul Farmer explains why and how we should tackle that challenge. We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

Written by Ashley Hamer April 9, 2018

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