Humanity on Earth
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Human Evolution Overview
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Understanding Calendar Notation
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Correction Calendar Notation
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Development of Agriculture and Writing
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Firestick Farming
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Collective Learning
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Thomas Malthus and Population Growth
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Land Productivity Limiting Human Population
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Energy Inputs for Tilling a Hectare of Land
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Random Predictions for 2060
Thomas Malthus and Population Growth Thomas Malthus's views on population. Malthusian limits.
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- The seventeen hundreds in Europe are often
- referred to as the age of enlightenment,
- it was a time we had come out of the renaissance,
- we'd rediscovered science and reason,
- and in the seventeen hundreds,
- we saw that come about
- with even more progress of society.
- As we exit the seventeen hundreds
- and enter into the eighteen hundreds,
- we start having the industrial revolution,
- and people saw the steady march
- of human reason, of human progress.
- And because of... because of this,
- a lot of people were saying
- 'hey, humanity will continue to improve and..
- and it will improve forever,
- to a point that poverty will go away,
- we will turn to this perfect utopian civilisation
- without wars, without strife of any kind.'
- And, there was something to be said about that
- you had significant improvements,
- in fact you had even more dramatic improvements
- once the industrial revolution started.
- But not everyone in the late seventeen hundreds
- was as optimistic,
- and one of the more famous not-so-optimistic people
- was Thomas Malthus.
- [writes Thomas Malthus] right over here.
- and I will just quote him directly,
- this is from his essay on the principle of population.
- [Quote] 'The power of population
- is so superior to the power of the earth to
- produce subsistence for man,
- that premature death must in some shape
- or other visit the human race.'
- Very uplifting.
- '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 success still be incomplete,
- gigantic inevitable famine stalks in the rear,
- and with one mighty blow levels the population
- with the food of the world.'
- So not..not so uplifting
- of a little quote right over here.
- But this was his general sense.
- He lived in a time when people were being
- very optimistsic that the progress,
- the march of progress, would go on forever
- until we got to some utopian civilisation.
- But from Thomas Malthus' point of view
- he felt that if people could reproduce
- and increase the population, they will.
- That there's no way of stopping them.
- So from his point of view, the way he saw it -
- so let me on that axis,
- let's say that, that is the population,
- and this axis right over here,
- let's say that.. that is time.
- So by his thinking
- and everything he'd seen in reality up to that point
- would back this up
- that if people had enough food and time,
- they would reproduce,
- and they would reproduce in numbers
- that would grow the population.
- So in his mind the population would just
- keep on increasing.
- It'll just keep on increasing,
- until it can't support itself anymore,
- until the actual productivity of the land
- can't produce enough calories
- to feed all of those people.
- So in his mind there would be some
- natural upper bound,
- based on the actual amount of food
- that the Earth could support.
- So let's say that this is -
- (let me do that in a different colour)
- So in his mind there was some upper bound
- there was some upper bound,
- and once you get to that upper bound
- then all of a sudden
- the vices of mankind will show up and
- if those don't start killing people
- well then all of these other things will -
- epidemics, er.. pestilence, plague and then famine
- people are actually starving to death.
- So in his mind, once you got to this level,
- maybe you had a couple of good crops,
- people are feeling good about themselves,
- they overpopulate.
- But then all of a sudden you have a bad crop,
- or because you have a bad crop,
- people start fighting over resources,
- and wars happen,
- or maybe the population is so dense that
- a plague develops.
- And then you have a massive wave of depopulation.
- And so you would just oscillate around this limit.
- And this limit some people would refer to as a
- Malthusian limit, but it's really just the limit at which
- the population can sustain itself,
- and from Thomas Malthus' point of view,
- he did recognise that
- there were technological improvements,
- especially in things like agriculture,
- and that this line was moving up.
- He had seen it in his own lifetime
- that this line had moved up.
- But from his point of view,
- however far you move this line up,
- the population will always compensate for it
- and catch up to it
- and eventually get to this Mathusian,
- eventually get to this limit and then the same kind of
- not so positive things that he talks about
- would actually happen.
- And some people now say
- 'Oh Thomas Malthus, he was so pessamistic,
- he was obviously wrong, look at what's happened,
- we have so much food on this planet right now,
- we've gone through multiple agricultural revolutions'
- And they are right, in the last two hundred years,
- since Malthus or since the early eighteen hundreds
- we really have been able to outstrip population.
- So this line, this line up here, has been moving up
- much faster than even population.
- So right now we actually do have
- more calories per person on the planet
- than we've had at any time in history.
- But it's not saying that Thomas Malthus was wrong,
- it's just saying that maybe he was just a little bit, er,
- he was a little bit pessimistic
- in when that limit will be reached.
- Now the other dimension where you might say that
- he was maybe wrong,
- was in this principle that
- a population will increase if it CAN increase,
- that if there IS food and there IS time,
- people WILL reproduce.
- And a good counterpoint to that is
- what we've now observed
- in modern developed nations.
- And so this right over here shows
- the population growth.
- I got this from 'The World Bank',
- that the population growth
- over some modern developed nations.
- You can see that the United States is pretty low
- but it is still positive,
- it's still...well, it's still over half a percent in,
- but even that adds up when you compound it.
- But if you look over here, Japan and Germany,
- and Japan and Germany have
- less immigration than the U.S,
- especially Japan, they are actually negative.
- So just this population left to its own devices
- especially if you account for people
- not going across borders,
- just the population itself growing,
- they actually have negative growth.
- So there is some reason to believe that
- this is evidence that Thomas Malthus was wrong
- or not completely right, he didn't put into account
- that maybe once a society becomes rich enough
- and educated enough,
- that they might not just populate the world
- or have as many kids as they want.
- They might try to do other things with their time
- whatever that might be.
- So I just wanted to expose you to this idea
- time will tell if Thomas Malthus
- if we can always keep this line,
- if we can always keep this line of food productivity
- growing faster than the population;
- and time will tell whether our populations can become
- I guess we could say, developed enough
- so that they don't in excrib (I can never say that word)
- [execrably], they don't always just keep growing,
- maybe they DO become a Japan or Germany situation
- in the world population,
- especially if we have a high rate of literacy,
- eventually does level off.
- So that it never even has a chance of
- hitting up against that Malthusian limit.
- But though I would introduce you to the idea
- and now you can go to parties
- and you can talk about things like Malthusian limits.
- And if you wanna know what country, you know,
- is maybe closest to the Malthusian limit right now,
- and we've talked about this before,
- but a good case of example is something like
- Bangladesh. They are right now the
- most population-dense country in the world,
- they have nine hundred people per square kilometre.
- And just to give you a sense of perspective
- that's thirty times more dense than the U.S is.
- So if you took every person in the U.S
- and turned them into thirty people in the U.S
- that would give you a sense of
- how dense Bangladesh is.
- And it's probably due, to a certain degree
- that it is very fertile land,
- it's the river delta of the Ganges
- essentially makes up the entire country,
- but they do, they've had in the past had famines,
- they gotten a little bit beyond that,
- but still you do have major problems
- with the flooding and the resources.
- So hopefully they'll be able to er,
- they'll be able to say ahead of the curve.
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