Factfulness: Ten Reasons We're Wrong About the World – and Why Things Are Better Than You Think (14 page)

This number increased only slowly for almost 10,000 years, eventually reaching 1 billion in the year 1800. Then something happened. The next billion were added in only 130 years. And another 5 billion were added in under 100 years. Of course people get worried when they see such a steep increase, and they know the planet has limited resources. It sure
looks
like it’s
just
increasing, and at a very high speed.

When looking at a stone flying toward you, you can often predict whether it is going to hit you. You need no numbers, no graphs, no spreadsheets. Your eyes and brain extend the trajectory and you move out of the stone’s way. It’s easy to imagine how this automatic visual forecasting skill helped our ancestors survive. And it still helps us survive: when driving a car, we constantly predict where other cars will be within the next few seconds.

But our straight line intuition is not always a reliable guide in modern life.

When looking at a line graph, for example, it’s nearly impossible
not
to imagine a straight line that stretches beyond the end of the trend, into the future. On the population graph on the next page, I added the dashed line to clarify what I think people are instinctively imagining. Of course they get worried.

Let me now give you another example that I know you are more familiar with. My youngest grandchild, Mino, was 19.5 inches long when he was born. In his first six months he grew to 26.5 inches. An impressive growth of seven inches. Impressive, but also scary. Look at his growth chart. I have added the intuitive straight line into the future. It’s terrifying, isn’t it?

If Mino
just
continues growing, he will be 60 inches tall on his third birthday—a five-foot toddler. By his tenth birthday he will be 160 inches tall—over 13 feet. And then what? This can’t
just
continue! Somebody must do something drastic! Mino’s parents will have to remodel their house or find some medication!

The straight line intuition is obviously wrong in this case. Why is it obvious? Because we all have firsthand experience of a growing body. We know Mino’s growth curve won’t just continue. We’ve never met a person 160 inches tall. Assuming the trend will continue along a straight line is obviously ludicrous. But when we’re less familiar with a topic, it’s surprisingly difficult to imagine how stupid such an assumption may be.

The UN population experts have firsthand experience of calculating population sizes. It’s their job. This is the line they expect:

The world population today is 7.6 billion people, and yes, it’s growing fast. Still, the growth has already started to slow down, and the UN experts are pretty sure it will keep slowing down over the next few decades. They think the curve will flatten out at somewhere between 10 and 12 billion people by the end of the century.

To understand the shape of this population curve, we need to understand where the increase in population is coming from.

This one, I’ll give you the answer right away. The correct answer is B. The experts are convinced the population will keep growing, mainly because there will be more adults. Not more children and not more very old people. More adults. Here’s the same population graph I just showed you, but now separating children and adults:

The number of children is not expected to increase, which we know already from this chapter’s first fact question. Now look closely at the children line in this graph. Can you see when it gets flat? Can you see that it is already happening? The UN experts are not
predicting
that the number of children
will
stop increasing. They are
reporting
that it is already happening. The radical change that is needed to stop rapid population growth is that the number of children stops growing. And that is already happening. How could that be? That, everybody should know.

Attention, now! Because this next chart is the most dramatic in this book. It shows the incredible, truly world-changing drop in the number of babies per woman that has happened during my lifetime.

When I was born in 1948, women on average gave birth to five children each. After 1965 the number started dropping like it never had done before. Over the last 50 years it dropped all the way to the amazingly low world average of just below 2.5.

This dramatic change happened in parallel with all those other improvements I described in the last chapter. As billions of people left extreme poverty, most of them decided to have fewer children. They no longer needed large families for child labor on the small family farm. And they no longer needed extra children as insurance against child mortality. Women and men got educated and started to want better-educated and better-fed children: and having fewer of them was the obvious solution. In practice, that goal was easier to realize thanks to the wonderful blessing of modern contraceptives, which let parents have fewer children without having less sex.

The dramatic drop in babies per woman is expected to continue, as long as more people keep escaping extreme poverty, and more women get educated, and as access to contraceptives and sexual education keeps increasing. Nothing drastic is needed. Just more of what we are already doing. The exact speed of the future drop is not possible to predict exactly. It depends on how fast these changes continue to happen. But in any case, the annual number of births in the world has already stopped increasing, which means that the period of fast population growth will soon be over. We are now arriving at “peak child.”

But then, if the number of births has already stopped increasing, where are the 4 billion new adults going to come from? Spaceships?

The chart on the next page shows the population of the world divided into age groups, in 2015 and then every 15 years after that.