I think, was when we turned over to seven -- I --, nobody knows. But nobody knows exactly

how many people there are, it's kinda hard to keep track; it's a big planet. But there

are about seven billion people on the Earth right now.

And they keep getting born, all the time. In fact, for every 2 people who die, about

4 are born. Every second, there are about four babies introducing themselves to this

world, and there are less than two people saying goodbye to it.

So, easy math here, our world's population is growing by about 2.5 people per second.

And as a reminder of this, during this video I'm going to have 2.5 ping pong balls being

thrown at me every single second throughout the entire rest of the video. Who's hitting

me in the face every single time?

[Intro]

Ok, instead of the balls, uh, were just gonna do a clock because I get nosebleeds pretty

easily, and I don't want you to have to see that.

So 7 billion people, it's hard to actually get your mind around how many people that

is, maybe if you were to just like sit down and count to 7 billion, it would take you

like 200 years or something.

On the other hand, there is plenty of space for them. If you took 7 billion people and

stood us shoulder to shoulder like we were at a Sting concert, those 7 billion people

could fit in an area the size of Los Angeles. We can fit on the Earth. There's space for

us all.

So as long as there's space for us all, what's the big deal about having 7 billion people?

Well it turns out people have been thinking about this for a long time, since around 1800,

when the world first clocked 1 billion people.

I know what you're thinking, you're like 1 billion, that's nothing, haha. Well at that

time all the economies in the world were based on agriculture. How much stuff we could grow

with human hands, farm animals, maybe a scythe and a wooden plow or something. So that kind

of technology, a billion people was really pushing it.

And the first like big-time thinker guy, to totally have a cow about there just being

too many freakin' people was a British economist named Thomas Malthus. Thomas Malthus calculated

that human populations tend to grow exponentially, while the ability of humans to feed each other

tends to grow more linearly. And so our growth as a species tends to outstrip our ability

to feed everyone.

And when that happens, it's pretty obvious what happens, you get the famine, and the

starvation. And for the people who are left over who don't die of those things, they can

get taken care of by disease and war.

Basically, Malthus thought that humanities natural state was to be cruel, miserable,

pathetic and sniveling in a pile of dirty underpants. In his essay on the principle

of population, Malthus observed... "The vices of mankind are active and able

ministers of depopulation. They are the precursors in the great army of destruction, and often

finish the dreadful work themselves. But should they fail in this war of extermination, sickly

seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their

thousands and tens of thousands. Should their success be still incomplete, gigantic inevitable

famine stalks in the rear, and with one mighty blow levels the population with the food of

the world."

Diseases also have an easier time taking hold, and of course starvation can kill off a lot

of people as well. Though he did make some pretty good points, as long as humanity is

well-fed, we're a pretty nice lot of people. But I have this problem too; when my blood

sugar just gets a little bit low, I start killing all of my neighbors -- that's not

actually true.

When you and your family's lives are threatened by starvation there's a lot of things that

you will do for food, including go to war. However, what Mister Doom and Gloom didn't

predict was the frickin' Industrial Revolution- which not only allowed the production of much

more food with far fewer laborers, it was also the impetus for this.

Uh, yeah. What that there is, is uh, the population of the Earth busting through Malthus's ceiling

and then his atmosphere and then his ozone layer and then his mesosphere and then his

- probably be pretty impressed by this. If you're not impressed yet, ah, just keep staring

at it. I can wait. I got all day.

It took humanity fifty thousand years to go from zero to one billion people, and then

to get from one billion to seven billion, about two hundred. So wow, Industrial Revolution,

thank you for allowing us to grow more food using machines, and for the fast and efficient

transportation that it takes to move all that food around to the people who needed it, and

thanks for the medical advances too, which help us understand things like the importance

of soap and the way that diseases worked, and as a result, humans now live about four

decades longer than the average guy in the eighteenth century.

Yeah! Industrial Revolution!

So Malthus might have been right about how frickin' stupid it was to be a human if the

Industrial Revolution had not happened. So now, the world's population is growing at

about 1.1 percent per year, which is a tiny bit better than the 1.3 percent per year that

got us here. If this current rate continues by 2050, we should have about 9.3 billion

people on the planet.

So the question is: at what point are these numbers going to outstrip our ability to feed

all of the people on the planet? It turns out actually that the question isn't how many

people can the Earth accommodate, it's more like: how many rich people can the Earth accommodate?

Because people in general, they tend to demand stuff for their survival like uh, oxygen,

water, and food. But rich people, we have different expectations. We, for example, in

America have a lot of agricultural crops, and we have to use a lot of fresh water to

water those agricultural crops. Do you want to take a guess at the number one irrigated

crop in the United States of America? Unless you've heard this statistic before, you were

wrong! It's grass! It takes more water to create lawns than it does to create all of

the corn in America.

We're using it like crazy; though it is a pretty scarce resource, we can use less than

one percent of the water on our planet. Most of it is salt water that we cannot use to

drink or irrigate crops, and 70 percent of our freshwater is frozen in glaciers. So clean

freshwater, non-negotiable and scarce. So what's next?

Ah, food. The world's combined food output could feed around 11 billion people, and yet,

there are 1 billion people who need food. So yeah that's one of the most pathetic and

infuriating things about our planet. So if there's enough food for 11 billion people,

and there's 7 billion people and a billion of them are hungry, who is eating all of our

food?

Food, is eating all that food. A huge amount of the food that we grow in America gets uh,

in turn eaten by livestock.

It's so hard to say the truth, which is that, but, rich people can do what they want. Now

when I say 'rich' it's important to note that I'm not talking about like, uh, the 99 percent

versus the 1 percent rich. I'm talking about if you have running water, electricity that

comes into your home, a computer that you can watch youtube videos on, and regularly

can afford to eat meat - you are a rich person on the earth, and you, you know sometimes

we just have to come to terms with the fact that we - even those of us who don't have

it great in America - have it better off than a whole lot of other people. There's a lot

of people in the world who don't get that. If you can have a hot shower, that's like

the peak of luxury to me.

So assuming that you are a first worlder, that you live in a developed country in Europe,

or you live in America or Japan, you consume on average as much stuff as 32 Kenyans. And

now the number of well-off people in the world is starting to increase dramatically and quickly,

and this is what we've always wanted for the world. So now we have all these moderately

well-off people walking around all over the planet, and it's great! Except that they require

more.

In the meantime though, a huge percentage of all of the babies that we're talking about

being born right now aren't being born to these rich people in the developed world.

They're being born in developing nations, and so the population isn't just growing.

It's growing in this weird, sort of scary, lopsided way.

Fact is, people in a lot of developed countries have kinda stopped having babies. Like Japan

for example, everybody's like 'Japan what are you doing? Why aren't you having any babies??'

and Japan's like 'Uhh don't know kinda don't feel like it.' So on average, Japanese people

are having about one baby per household. They're not even replacing themselves, compared to

two or three babies in America or like, five or six in most of Sub-Saharan Africa.

So developing nations are having a baby boom, and that's what happens when you get, you

know, vaccines and antibiotics and safe water and better sanitation. You get fewer babies

dying, and we are all completely and totally in favor of fewer babies dying, I hope. But

it also means that there are going to be a lot of new Sub-Saharan Africans in the next

50 years or so, and that is where a lot of the 1 billion currently hungry people are

already living.

So while those of us in the developed world are not having any babies at all and yet consuming

enough food for like, four truckloads of babies, the governments in developing countries are

struggling with where to put all of these new people and how to feed them all. And you

also get what is known as a 'youth bulge'.

A lot of developing nations are currently seeing a huge explosion in people between

the ages of 15 and like 29. And all of those youth are out there, looking for the same

jobs, all at the same time, feeling generally hormonal as youth do, and being pretty unhappy

with their lot in life.

Some social scientists conjecture that youth bulges like this have been responsible for

nearly every insurrection in history, from the English revolution in 1640 to the more

recent Arab Spring. And neither of those things were bad things, but we should be aware that

there may be more of it coming.

And another thing that Reverend Malthus never thought of is: what happens when humanity

gets together and takes over the whole frickin' world? Seriously, because it turns out that

there are actually supposed to be some other things living on this planet with us.

Through our desire for more space and more stuff, we're putting pressure on pretty much

every habitat on earth. So much so that worldwide, 52 species of mammal, amphibian and bird move

one category closer to extinction every single year. You know, this world is pretty big,

but there's only so much room and it turns out that Bengal tigers aren't particularly

well-suited to high rise living. So the more there are of us, the fewer of literally everything

else there is, except for like, things that we enjoy eating, and petting - dogs and cats

as well; their populations continue to grow.

So happy birthday new people, welcome to Earth. I'll try not to screw it up too much for you.

If you're interested in more things to do with global population, please check out the

description below. There will be links in there for our source materials. You can also

ask us questions and leave ideas for future episodes of SciShow in the comments and get

in touch with us on Facebook and Twitter as well. Goodbye.