A common misunderstanding is that if we save all the poor children, the world will become overpopulated.

This may sound logical, but it's wrong.

It's the other way around!

Saving the poor children's lives is required to end population growth.

Now! Look at the UN numbers.

Poor parents on average have five children. And one dies.

Look! Two parents are replaced by four surviving children in the next generation.

This means population is growing very fast among the poorest.

This is the average family in the worst off places like Congo and Afghanistan.

Today, where child mortality is highest, that's where population is growing faster than anywhere else.

How many people live like this?

There are seven billion people in the world. One block: one billion.

The poorest two billion...

...they live like this.

The other five billion...

...they have this average family. Two parents having two children and there are few child deaths.

This is the majority of the world population, not only Europe and the US.

It's throughout religions and cultures: China, Iran, Mexico, large cities in Africa.

Today in most populations children just replace parents.

And the size of generations are no longer increasing.

This means the population will stop growing.

How did so many people end up with small families?

Well, their children stopped dying.

As they left extreme poverty and girls got education, parents no longer had to

compensate for child death by having many babies. And a large family stopped being

an economic necessity or a social status symbol.

And with modern contraceptives, parents across the world, the majority,

decided to have a small family.

So, by saving the lives of poor children and helping the last two billion out of poverty,

these parents will also decide to have fewer children.

And fewer.

Eventually...

...reaching the two child family.

That showed the UN family size forecast up to the end of the century.

Then the world population is expected to stop growing.

Before it stops, another four billion people will be added to the world population.

Four billion more. That's a lot of people!

But the longer poor children keeps dying and this change is delayed,

the more billions will be added.

So ending population growth starts by saving the poorest children.