Population; Sustainability; and Malthus: Crash Course World History 215 Video Lecture | A Complete Guide to World History : 2 - World Knowledge

Hi, I'm John Green. This is Crash Course World
History and today we're talking about one
of my least favorite subjects, the end of
humanity.
Mr. Green! Mr. Green! Does that mean that
you can see the future? If so, how do things
work out with Amanda Key?
Oh, me from the past, the phrase "work out"
implies that there was a relationship to work
out, which there wasn't, and there will never
be.
However, you do currently know your eventual
wife. But I'm not telling you who she is,
because if I do you will screw it up!
So we're not gonna look at the actual end
of humanity today. We're going to learn about
a theory about the downfall of civilization.
And unlike all the true theories, this one
doesn't involve aliens, or robots, or robot
aliens. But it is related to environmental
catastrophes of the man-made variety. Today
we're going to look at population and the
most persistent theory about population
growth and its effect on humanity.
The one proposed by Thomas Malthus.
And what's amazing about the persistence of
this theory, is it's complete lack of connection
to actual human history. All right so in 10,000
BCE fewer than a billion people lived on earth.
Nearly 12,000 years later, around 1800 CE,
human population had grown to...
still under a billion.
At about that time, an Anglican minister,
named Thomas Malthus wrote an essay on the
principle of population. That explained why
this slow population growth was the way things
were always going to be. Malthus saw the growing
number of poor people on the English streets
and he did what any reasonable thinker would
do, he analogized them to rabbits. He reasoned
that the same forces that checked the population
of rabbits would limit humans too. Predators,
harsh weather, epidemics, and starvation.
Now it turns out that humans have ways of
dealing with predators, we killed all the
lions. And also we've got this amazing way
of dealing with harsh weather that rabbits
have never figured out called clothes. Not
to even get in to fire and housing.
So that leaves us with alien predators, disease,
and starvation as the big obstacles. Okay,
we're going to address these one at a time.
First, Arnold Schwarzenegger already took
care of the alien predators. Thank you Mr.
Schwarzenegger, in exchange we made you
Governor of California.
Then we have disease. So around the time Malthus
was writing, disease was becoming less dangerous
to human populations. And then there's starvation,
right, well we've argued in the past that
starvation is generally a man-made problem.
But to Malthus, it was still a natural disaster.
For Malthus, uncontrolled reproduction was the central
problem. Remember, he was, you know, coming
from the context of rabbits.
He explained it through math. Humans could
reproduce geometrically, capable of doubling
population every 25 years, but land on Earth
is finite and at best, it could only be coaxed
into producing small, arithmetic, increases
in food. So you've got population growing
geometrically, food growing arithmetically,
all the people are gonna die. Now among simpler
creatures, the theory went food shortages
caused immediate famine. But humans would
continue to eek out ever more desperate lives,
as increasing demand raised the price of food,
and clothing, and bread, and medicine.
Powerful individuals and nations would seize
the assets of the weak, but even some of the
strong would fall victim to hunger and disease.
Inevitably the population would then dip low
enough for the land to recover. Giving another
generation a chance to repeat the same mistakes.
Over time then, human population would remain
roughly constant with the natural fertility
of the land. Because he was such a fun guy,
Malthus called this theory of history "The
Cycle of Misery." This essay is one of the
most influential pieces of writing in history,
along with a handful of other works, it established
the methods and importance of the modern field
of economics. It opened the door to the universe
of evolutionary science. And most immediately,
Malthusian theory played a devastating role
in the Irish Potato Famine of 1846-1851. Let's
go to the sure to be depressing, Thought Bubble.
Nearly 1 million Irish people died of starvation,
disease, and violence during the famine, which
was triggered when a fungus wiped out the
one strain of potato grown in Ireland. Had
Ireland's poor population had access to the
thousands of other varieties of potato or
aid to purchase more expensive crops, the
suffering may not have been as terrible.
But official English policy toward Ireland,
as determined by its colonial master Charles
Trevelyan, was to give no aid nor allow anyone
else to give it either. He blocked American
ships filled with corn from reaching the island.
He allowed Irish farms that grew crops other
than potatoes to sell them straight to England.
Now hundreds of years of anti-Irish Catholic
hatred, were the roots of England's cruel
policies. But Malthusian theory also played
a role. In the century before 1846, Ireland's
population had grown significantly, and many
English thinkers saw the famine as an outcome
of Malthus' predictions. From this point of
view, providing food or aid to the Irish was
futile - it could only delay the cycle of
misery until it's downward swings scythed
down even more people.
Trevelyan thus felt assured of pronouncing
that the only remedy for the starving was
for them to die, and let their corpses serve
to remind the survivors not to have sex. Quote,
"the judgment of God sent the calamity to
teach the Irish a lesson and that calamity
must not be too much mitigated".
Trevelyan reassured people upset about the
news of starving children, the real evil with
which we have to contend is not the physical
evil of the famine, but the moral evil of
the selfish, perverse, and turbulent character
of the people.
Thanks Thought Bubble. So why did Ireland
want independence in the first place? Oh right,
yeah that! So by 1852, emigration and starvation
had shrunk the population of Ireland from
about 6.5 million to 4 million. In 2010, the
islands population was still lower than at
the famine's start. So Malthusian theory seemed
to have it's airtight proof, right?
Well, no.
In fact, even as Malthus was writing, the
curve of human population growth was beginning
to slope upward. The increase in population
was so gradual that all Malthus noticed of
it, were the outliers, the poor clinging to
life. But the growth in the number of human
beings was far more permanent than Malthus
ever imagined. In fact, it was unstoppable.
From 1750 to 1850, right when Malthus was
alive, the number of humans on Earth grew
by half a billion people. From about 800 million
to 1.3 billion. By 1960, the population reached
3 billion. And since then, the world has added
a billion humans roughly every 15 years. Sometime
in 2009 or 2010, the United Nations estimates
that the Earth's 7 billionth person was born.
Consider that contrast, at the very moment
that Malthus was writing that it was impossible,
human population was beginning it's rocket
like acceleration. So what did he miss?
Well, Malthus was like an A+ student in the
subject of human existence, he was right for
like 95% of history. But it turns out, grades
aren't a super accurate predictor of success
in life. Malthus should have looked past prominent
disasters like the potato famine and recognized
that two major revolutions in food production
were occurring while he was alive. One of
the reasons that he struck out so spectacularly
is that, like many Western thinkers,
he wasn't paying attention to China.
So Chinese farmers had altered the land, and
used a number of inventions like dykes, and
paddle wheels, and bicycle chains, to grow
rice in man-made paddies. It took a lot of
labor, but it paid off. Especially when they
discovered that by using the entrails and
bones of the fish that swam in the water,
they could get you know, fertilizer! And then
they could grow two rice crops in one year.
Thus, the secret of China's greatness: food!
And with the benefit of added surplus, fortunate
people in China were able to free up their
time to study and to invent. Yet, while the birth of this
system had begun in the ancient past, additions to it
continued throughout Chinese history and
progressed straight through the Qing dynasty.
But agriculture was also changing in Europe
during Malthus' lifetime. Like there's Jethro
Tull's seed press, the crop rotation system
developed by Charles "Turnip" Townsend, and
animal husbandry practiced by scientific farmers
such as Robert Bakewell, who increased the
size of his sheep by selective breeding. So
it kinda seems impossible that Malthus could
have missed this revolution, because he could
see it from his house in Surrey England. But
from his perspective, that agricultural revolution
had the opposite effect of what had happened
in China. Like instead of giving people more
food, and more comfort, it seemed to Malthus
that it was driving them to greater misery.
That's because, for lots of Europeans the
agricultural revolution was largely about
evictions. The most important innovation of
Europe's agricultural was largely invisible. It was
the decision to treat land as private property.
So for most Europeans, the concept that individual
humans could own, like, land was a foreign
concept. Even as late as 1500, most of Europe
conceived of land as rightly belonging solely
to its creator - God. And then God's anointed
on earth - kings and the Church - could parcel
out packets of land to people they chose.
But any land not specifically granted to a
land lord, remained open to anyone who wanted
to use it. This open land was called the commons.
And in parts of Europe it made up more than
half of the territory. But then around 1100
CE, British monarchs found themselves perpetually
strapped for cash and they needed new taxes.
So in return for voting for tax increases
and gifts, the crown granted enclosure acts
to rich Englishman. Giving them the right
to fence off the commons and claim it as their
own. So the people who'd used that land to
graze animals, or cut wood, or grow crops
could be forced off of it. And for the first
time, richer people could maintain miles of
fenced in property to pasture their sheep
or dig mines. Meanwhile the dispossessed,
deprived of their opportunity to grow or hunt
their own food, turned to beggary and theft,
and to London. Where they hired out their
labor for wages.
Wages?! That's not how humans should live!
Having to fill out time cards and punch clocks!
Wait - Stan...don't you make wages?
Ugh, it's horrible. Myself, I live off the
land. If I can't grow it, I won't eat it!
So by the time Malthus was a young man, things
weren't great for the poor and dispossessed.
So it's a small wonder that Malthus only saw
the downside of the agricultural revolution.
Only through historical hindsight, do we know
that private property accelerated incentives
to experiment with new methods of food
production, which dramatically increased
the amount of food produced.
Like before enclosure, it wouldn't have made
sense for someone to buy a seed press and
plant neat rows of seeds because anybody with
a cow could have trampled on them an hour
later. The lower food prices created by more
food supply began to ease the cycle of misery
that Malthus described, although only just
barely. So in fact, agricultural innovations
proved that Malthus was almost entirely wrong.
So, why is he still influential? I think because
there's a very seductive logic to the idea
that resources, especially food, are finite.
I mean, we live on one planet that has a certain
amount of arable land and surely at some point
humans will suck up all of the resources.
And this is especially true in the age of global
climate change. In 2014, the UN Intergovernmental
Panel on Climate Change issued a report that
warned of the potential for warmer temperatures
to restrict food supplies in the face of growing
demand. In fact, it claimed that rising temperatures
had already diminished wheat production by
2% per decade. While demand for food was rising
at 14% over the same period. Food prices,
which had been declining steadily until 2007,
have been volatile since then. Sometimes leading
to famine other times to political unrest. And those
are real problems that may yet prove disastrous.
But other doom and gloom scenarios regarding
population and food, most notably the 1968
book The Population Bomb, have proven wrong
at least so far. In fact fewer people will
die of starvation this year than died 500
years ago of starvation, even though we have
far more people on Earth. And there's still
lots of room to improve agricultural yields.
But simply knowing that Malthus was wrong,
isn't as interesting as thinking about why
he was wrong. Malthus underestimated how successful
we would be at adapting to environmental constraints.
And he underestimated the role that technology
and innovation could play in creating a world
where more humans could live. Now of course that
hasn't come without its costs - including climate change.
And that's why I think Malthus remains so
influential. Human existence is not a zero
sum game. It is possible for me to benefit
and other people also to benefit. But it's
also true that many resources that we imagine
as infinite - aren't.
Thanks for watching. I'll see you next week.
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