Human Population Growth - Crash Course Ecology #3

[@fartzinwind]

"So they are not having as many OOPS children" Best way of putting that lightly ever!

[@x77punk77x]

Less educated and less intelligent women are more likely to have "oops" children. It has been documented that they are far more likely to fail to use birth control or to use it incorrectly.

[@tanz5229]

Table of Contents 1) R vs. K Selection Theory 01:41 2) Causes of Exponential Human Growth 03:24 3) Human Carrying Capacity 03:30 4) Ecological Footprints 06:40

[@kkl4448]

Spider-Man Gaming Ur the goat

[@sopmac9998]

THE GOAT 🐐

[@glitterglitterglitter222]

Thankkks

[@ItsJustme526]

When you're a broke college student and can't afford the text book so you come onto crash course and it saves your life. Yea that's me

[@johnnyblueye]

Same this video just gave me my final exam answer done and done in 10 minutes.

[@error_d2c]

sad... very, very sad

[@trishastokes6945]

Mary Herrera lmfao 😂😂😂 got a quiz on this shitz and I couldn't get the book caz there's no PDF online bruuuuh 🙄

[@nickarmagno1045]

rent it for $20

[@lane6953]

Had to answer questions on this for my freshman biology class hahaha

[@Davegaeth]

"... human population is important to think about because we kinda need to do something about it. And I think pretty much every other species on the planet would agree with me on that." I couldn't agree more. Thanks for pointing out that other species are sharing the Earth with us, it seems that some people disregard that fact when talking about human overpopulation.

[@thecrippledpancake9455]

We don’t necessarily have to do anything about it. Eventually nature will care of us....... and by that I mean theirs gonna be a huge die off of people because Earth won’t be suitable anymore 🙃😉

[@heathermariegaming]

I know!

[@1990SammieJ]

I just want to say I love you guys at Crash Course! You got me through uni and I'm now an ecologist, and it all started revising here :3

[@MrDavidBFoster]

I like that he says human population is a problem that needs to be dealt with, _"and I think every other species on the planet would agree with me on that."_

[@Acproe]

*Thanos Snaps

[@deeznutz6595]

@@Acproe "Mr Green I don't feel so good"

[@mecchabaron64]

Doing the math in my head, I realise more and more how much we are SCREWED.

[@bribri2925]

No one: Not a single soul: Me: Did we hit our cap yet? Corona: *Yes*

[@joachimschoder]

The problem with setting an absolute limit for human population is that it uses head counts while the real limit heavily depends on the average consumption of energy, non-renewable and renewable resources.

[@arckopolo]

You are an amazing help to about 60 of us through our revision of Population and Community Ecology course which we have an exam in next week at Edinburgh Uni. Big thank you from all of us!!!

[@brocktallutoboi3955]

Anyone else watching this for school so that your teacher doesn't beat you?

[@mostkilz]

I was bored and forcing myself to complete my summer ecology homework when I get to the r and k selection of my packet. Then the thought of crash course ecology hits me in the face, yelling to me to close my textbook and watch the video again. I do so, and thanks to Hank, I am able to answer the questions about r and k selection without the aid of my textbook. Screw textbooks, go online video education :D Keep up the good work on your new chemistry videos but I'll always look back to older vids!

[@BigT.Larrity]

Think abut this: you can never be truly sure you aren't a oops children.

[@phillipreed4919]

The Green Brothers are the best thing to ever happen to KZbin.

[@peregrination3643]

I've read a lot of ecology books and taken several classes, but this is the first time I've had r vs K (the choice in letters and capitalization) explained. And of course, I always forget to ask in class.

[@LordOrx]

I love discussions on human population growth and human carrying capacity, since it isn't something most people tend to think about. An analysis of the probable events of a human population crash, and the avenues through which such could occur, would be fairly interesting. Putting that into perspective would give some of those who are more short-sighted insight as to why human population growth and sustainability are issues to address.

[@brightmal]

From what I've seen, an increase in access to electricity, education, and something approaching gender equality causes human to shift rapidly from the R to the K end of that spectrum.

[@SuperKoopaguy]

I'm going to adopt rather than have my own children. People need to have

[@jessicayu1926]

ras144 Remember that developing countries have fewer access to resources such as food, water, sanitation and health care. Thus even if there's a high birth rate, there's also a high death rate (especially infant mortality rate). So really, their net contribution to overpopulation is smaller than we think. (To what degree of developing are we talking about?) In comparison, when you think of some developed countries, people are living upwards from 80. Honestly, the answer is difficult. Maybe we should all become population ecologists.

[@jessicayu1926]

I do know about the population pyramid. Thanks for bringing that up. Okay, just continuing the conversation. Let's say we're talking about China. China does have the harsh one child policy, so the reason why their population continues to grow is just there massive already present population. Also, even when talking about China you have to compare cities and villages. There are cities (Shanghai, Beijing) that are highly developed, but also many many villages that live at lower standards of life. Of course, the largest populations do center in cities. However if we're going to solve this problem, we're going to have to limit both population growth and resource consumption (and even then we will hit the carrying capacity because the capacity is not infinite). Easiest current answer to the latter? Being vegetarian. Plants take up much less land to produce. However, I fully intend to grow to my full stature before I consider becoming vegetarian. I don't know much about India so I can't say. Also out of curiosity, if the answer isn't difficult, what would you propose to solve the world's overpopulation and resource waste problem?

[@mercedesperez5008]

if you go to settings and change the speed to 0.5 hank becomes drunk

[@donnybrasco9026]

+Mercedes Perez this is the best thing i have ever seen on the internet.

[@velosistar237]

+Mercedes Perez this is what i needed in my life

[@moiralarkin1148]

I can't stop giggling

[@StefaniaCzech]

omg i needed that laugh! lol

[@macaylagregory573]

HahahahahahahahahahahXD

[@sparshsharma8854]

The interesting thing is that since this video came out, we added another billion to the population.

[@afinnandfaunaproductions6557]

Phew, I wish he would've taught me in high school! Thanks for these videos.

[@taylorfrench6722]

Human Population Growth - Crash Course Ecology #3 NOTES 1: Human Population Growth 1.1: Human population has increased exponentially for a few hundred years, and it’s important to know why this is happening and how long exponential growth can be sustained 2: R vs K Selection Theory 2.1: Quantity vs quality determines how individuals reproduce, known as the R vs K Selection Theory 2.2: Some organisms will aim towards exponential growth while others will only reproduce up to the carrying capacity 2.2.1: R-Selected species go by the former (r stands for rate) while K-Selected species go by the latter (k stands for carrying capacity) 3: Human Growth 3.1: Humans should lean heavily towards K because they only have a few children, but invest in them heavily 3.2: Instead, humans have begun to resemble an R as shown by the exponential growth of human population 3.3: Humans have removed or mitigated limiting factors, allowing carrying capacity to grow indefinitely 3.3.1: Agriculture became mechanized around the 17th century, increasing food production 3.3.2: Medical advances such as vaccination allowed more children to survive to adulthood and make their own children 3.3.3: Sewage systems, beginning in the 1500s, prevented the spread of disease 3.3.4: 20th century advances allowed human habitation basically anywhere 3.4: Every human increases carrying capacity slightly, but this will end eventually 4: Ecological Footprint 4.1: An ecological footprint determines what resources each person requires, and differs based on individual habits 4.2: While we can theoretically fit 1 trillion people on Earth, they would conflict over space and resources 4.3: Also, other species suffer from human overpopulation as there is limited and decreasing available space, water, and food, giving support to the theory that we are currently living through an extinction event 5: Limits to Growth 5.1: Growth rates peaked around 1962 and have decreased since as cultural shifts have led to women entering the workforce 5.2: Also, back when most people lived on farms, having more children was an asset as they could provide free work and were relatively cheap 5.2.1: With more people living in cities, children have become liabilities as they are expensive and can’t provide labor for the family

[@samueltanjw]

"Oops children" Hahaha that cracked me up. Great video!

[@AsdBiggs]

One hour till my uni ecology module exam and this is how im learning... wish me luck...

[@Shil0hhhhh]

did you pass

[@icarlyrocks1000]

So glad you mentioned how meat eating isn't as sustainable as being vegetarian. Not many people make the connection.

[@dec081]

Very educational and fact filling. Keep up the great work.

[@doubleohtyler6958]

you should get your own radio station

[@Clockworkcityofpain]

I think it would've been very important to point out that feeding vegans occupies even less land than feeding vegetarians. According to some estimations, if the whole world went vegan and we stopped feeding all of our food (up to 70% of all grains produced in the US) to animals, we could raise our carrying capacity greatly, as more and would be available to grow food for humans. And we would also save millions of tons of water, greatly reduce our waste and most importantly, we would give wildlife a chance to recover after human intervention almost annihilated it

[@dontxtalk]

Eventually, the same problem would still occur. But have fun with your trillion people

[@alcaeus]

There is land that is unsuitable for farming but would be great for raising sheep, or cows and if everyone went vegan we would be wasting the food production that land could provide. ultimately, eating both veg and meat is the best course for carrying capacity if we eat very little meat and more veggies.

[@PaulHoward108]

Vegan diets are too difficult for the average person to follow. It's smarter to promote vegetarian diets because of the ability to attract many more people, whereas demanding veganism often has the opposite effect.

[@Holidayinspain76]

This is way to simplified, yes we should try to reduce population growth but that won't happen by individual decisions in western countries. We need to increase income and education for women in poor regions of the world, that will have a way larger influence than your individual decision. And secondly we should definitely reduce our meat and dairy consumption. Meat is one of the biggest polluting factor currently, and feeding a growing population will be way easier if we stop eating meat

[@dulala2564]

Watching this and listening to Frederic Chopin - Nocturne op.9 No.2 ...this video became 10 times more epic than it initially was.

[@FlyingPigMD]

this was already in my mind when I watched this. It was only after I saw this that I did them simultaneously. Fits! We're gonna have to do something about this population problem. Yes, it's a problem! Colonizing another planet is only temporary.

[@grobanlover292]

Im usually cautious about hearing people talk about this topic because its been historically used in very dangerous or problematic ways. Im glad this handled this topic responsibly

[@merrymachiavelli2041]

Personally I support a mix of Boserup and Malthus. What Boserup's theory does is delay the process that Malthus describes, but Malthus is ultimately true in the end. Also, I think it's worth mentioning that Malthusian disasters, when they do happen, will happen regionally not worldwide. The developed world may not experience them, because we can buy our food, but developing regions will. Most of the developing world is experiencing high population growth rates and, in regions such as the Sahel and East Africa, increasing desertification, soil erosion and climate variability. Carrying capacity is not quite globalised yet.

[@merrymachiavelli2041]

***** Cultural hangovers. The best way to reduce the birth rate in a place has been demonstrated to be raising the status of women in a society. Generally speaking, having educated women tend to start having children later (leading to less children overall) but it also leads to lower infant (and mother) mortality rates and less couples continuing to have children after having had daughters in the hopes of getting more sons. The "open everything up to the markets!" approach can be problematic. The main impact of opening up the markets in sub-saharan Africa has been many farmers switching to cash crops like coffee or cocoa. Fun Fact: Coffee is Ethiopia's largest export (I used to study Geography, sue me) This is fine on the surface, but it leaves countries more vulnerable to famine and global economic woes. Also, no matter how open the markets are sub-saharan African economies are, they are still likely to rely on agriculture, after all, *someone* has to grow food in the world.

[@merrymachiavelli2041]

***** Fair point. I agree that, for African economies to develop to a high level, there need to be (relatively) free markets. And there is evidence of this if you look at countries like Sierra Leone (ignoring the recent Ebola outbreak) However, I'm still not convinced free markets alone will solve the problem. It's far too simplistic just to say "sell off your grain reserve!" to Malawi and expect that to solve everything. China is actually quite a good example, while it is certainly a more economically liberal country that it was during Mao's era, a large part of the reason for its rapid growth is savvy state management of the economy. This is part of the reason it overtook India in terms of growth rates. First and foremost, what Africa needs are good political leaders, capable of negotiating from a position of strength in international diplomacy.

[@SuperPorcupineFish1]

Lol, "oops" children.

[@NeonsStyleHD]

That's the problem with our population problem. Doing something about it. There are very few people on this planet that would agree on regulations to control our population, either through a China like one child policy, or even harder to think about, removal of non productive people (Nazi's crap idea). Finding a workable solution to this problem is one of the biggest problems of our world. Climate change, the extinction event and so many other of the current crisis all are caused by the one problem. Over population. My guess, is disease will step in and cull us before we choose to do something about it.

[@khoatran-pc6tb]

...or we might have nuked up eachother before anything happened

[@huckleberryharrison6248]

It will be horrible when it happens. The most simple answer is some kind of state sponsored "natural selection" but, as you said, no one wants it. Culling it is.

[@R3tr0v1ru5]

+NeonsStyle Your guess might be a good one. Bacteria are evolving too quickly for our antibiotics, surely in time a deadly super virus will sweep the population...

[@NeonsStyleHD]

Deathbyblackhole Probably. It sounds cruel to say it might be a good thing.

[@R3tr0v1ru5]

NeonsStyle I didn't mean it would be a good thing. I meant that your guess might be accurate.

[@Tutorp]

Regarding the human growth rate and its decline: While the things mentioned may well be contributing factors, neither the declining child mortality rate (which first contribute to massive population increase and, after a while, a large decrease in birth rates) or the aging of the population is mentioned. These are both very important contributors to both the growth and the decline in growth - according to Professor Hans Rosling, they are by far the most important ones.

[@EternusVia]

It's really nice to see intelligent comments in the top two.

[@LuffyissHere]

lmfao "'oops children'' :D

[@timdewit6088]

Minor gripe: the father of microbiology was Antonie VAN Leeuwenhoek, not 'Anton von Leeuwenhoek.' He was a Dutchman from Delft, not a German. Very interesting video otherwise. :-)

[@timothyle3153]

Honestly this is a very serious topic as most of the world's major problems are caused by the human population staggering number. It's something to think about and it's an interesting topic to discuss I believe. There's a book known as Inferno by Dan Brown that talks about this subject that I believe people should read to become more aware of this problem.

[@j.r.bumgarner5821]

Personally I'm fascinated by what technology can do to improve 'carrying capacity' because in a non-agrarian society what we can do with our two hands is exponentially greater than what we could do back when we all lived on farms.

[@mironeqq]

10 YEARS LATER... 8 BILLION HUMANS :o

[@mewtew8006]

Overpopulation is by far the biggest issue of our time

[@JamesZaworski]

Malthus had a thing or two to say about survival and sustainability, and carrying capacity of the environment. I was born in 1965 and there were about 3.5 billion people, and now there are more than 7 billion. Don't blame me, I didn't make any new ones. I did, however, plant 15,000 trees. So don't blame me.

[@MrLeew3]

Who here is watching this and is in Ap Human Geography lol

[@QuantumRuse]

me too lol

[@86hardluck]

There was a TED Talk about declining human birth rates and the various factors that cause that. The guy calculated that the human population would max out at around 10 billion and stay there.

[@kman2324]

He did 100% mention health and the declining child mortality rate. It was right here @4:40

[@emilyadder1574]

In 40 years, if our exponential growth rate continues, we will hit our estimated maximum potential. In our lifetimes we might see the highest population of humans the world will ever see. Kind of a frightening thought. (Also, thank you Hank Green for helping me study for my biology exam)

[@jdftba4164]

I've always thought it was interesting that humans are so concerned about their affects on other animals. (I mean, don't get me wrong, I love animals, but hear me out) Like, if any other species was having this kind of exponential growth, they wouldn't care that they are beating out others. Actually beating the others is kinda the point. So even though it would make total sense for us to be like "Survival of the fittist!" and just kill all the other animals that aren't useful to us, we don't do that. Even though we have no real obligation to help other species, we still do. Weird, right?

[@cantflyforshit]

true but i think its to do with culture like dat guy said in the video up there. i mean look around you we are saving endangered species as if we would die if we did not! weird, right?

[@freddyfredfrederickson]

Naser Alomoush We WOULD die if we didn't attempt to limit our effects on the natural environment. It's called the ecosystem.

[@Doomroar]

If we don't help other animals we die, in the end the only animals that are important is the Arthropods the insects who go around helping plants, go and watch again the non-vascular plants part on Biology CC.

[@spiehole]

Now that China got rid of its 1 child policy, what's gonna happen?

[@GhostInTheShell29]

They greatly reduced the restrictions, but the restrictions are still to strict, and they waited far to long to reduce the restrictions. Their population is going to start falling soon, and won't stop for a long time. Even if they get their fertility rates back up to 2.1 its way too late to maintain over a billion people. If it takes them 30 years to get fertility rates back up, which it probably will. Their population could fall to half a billion.

[@RhianKristen]

GhostInTheShell29 I'm sorry, but I think that's a good thing. It will definitely hurt short term, but it'll help long term. Half a billion is way too many people in the world for my liking, let alone one country.

[@GhostInTheShell29]

RhianKristen The problem is the population will be almost entirely old people. Think about it a family that follows the 1 child policy for even two generations. There will be 1 grandchild, for four grandparents. It leaves you with a mostly non working population that needs to be supported by an ever decreasing supply of workers. Look at Japan's economic troubles they are already experiencing a shrinking population, and at the same time the average age of their population is going up.

[@scraggyboi]

Myrna well, hello there 18384838 billion

[@UntilTheeEndd]

@@GhostInTheShell29 Can you explain this in more details? This is interesting

[@lmmortalZodd]

in places where there is a shortage of resources the energy footprint will rise as a result of,say,pumping water from 200 km away and maybe cleaning it. it will then be easy to determine where the more habitable places are

[@sophiastef1568]

YOUR ACCENT DISTRACTS ME! WHY IS IT SO FUNNY?

[@rainbowkat1516]

I wonder what the planet will be like in 200 yrs.

[@Burtonesque413]

Dead. It will be dead, lol

[@SuperOtakuKyo]

We need to find alternatives so we can all live besides tearing down vegetation

[@luke-be8yw]

How the hell would 1 trillion people fit on earth?!

[@Doomroar]

With communism!

[@GhostInTheShell29]

If you had 10k square miles with the population density of Manila 111,000 people per square mile. You could fit over a trillion people on a relatively small part of the earth. Feeding, sewage, water and power supply for that many people requires technology science fiction writers have dreamed up, but aren't in our reach yet. Give it a few thousand years and we might be there.

[@timpeterson2741]

I once read an article that said if the United States had the same population density as Hong Kong there would be 6.8 billion people in the United State. Just stack them higher to get to 1 trillion.

[@monkey314159]

GhostInTheShell29 Check your math. You need 9.1 million square miles. There's only about 30 million square miles of land that isn't desert or arctic.

[@viktorkardell9366]

RoarOfDamnation Huh? I, even as a communist myself, do not see what you are talking about. If you are making a joke, it is in poor taste. If you are not, please explain yourself. Thank you, sir.

[@PollyDumfa]

5:50 is the best description of humanity's rise I have ever heard

[@mikeaye8998]

Just a stylistic note...Why did you guys choose to go with such a minimalist motif for this branch of Crash Course? The images you guys used through Thought Bubble and Thought Cafe were helpful in making the episodes entertaining AND enlightening.

[@42Evilgirl]

Hank do you have a map? Cause I'm lost in your eyes ;) xx.

[@jamesmallon1631]

HAHAHA! brilliant commet !

[@lauravilbiks]

At least you mentioned vegetarians 👍

[@michaeltariga5285]

We need to colonize Mars. And then go Total Recall.

[@scienceforall9]

that would cost TRILLIONS, we could be better off on the moon

[@michaeltariga5285]

science and more Then we need to colonize the moon. And then go Total Recall.

[@FortuitusVideo]

We actually made our first steps to colonizing space. But then we all saw a shirt with half naked women on it and we freaked the fuck out.

[@BigAl1234567AlBig]

we would be better off colonising the oceans

[@NathanDoemner]

Big Al I agree...

[@courtlynreynolds5066]

From the wise words of Dwight K. Schrute, "There's too many people on this earth. We need a new plague."

[@blubberinghumdinger35]

Nice work! "oops children" haha cracked me up

[@InfoPro89]

Dude, how the fuck does he know about all of this, psychology, history, biology... ??

[@carollawliet7345]

My guess is college, the internet and books (with a dash of common sense to wrap it all together)

[@SuperOtakuKyo]

It isn't that hard to expand knowledge. Us humans have all these resources some just choose not to use them.

[@lock_ray]

InfoPro89 script...

[@ClaySmileSoil]

They have a team of professors, script writers, teachers and internet resources. Hank may have some knowledge about all of this but for filming he's effectively reading off a script.

[@JMcomments]

im scared about what will happen when we go to 11 billion by 2100. i think its gonna be the end of the world tbh.

[@marginelouis6674]

I think it'll level off as countries develop

[@mrme1821]

or maybe Elon Musk will get us to Mars by then

[@tiffanytong1964]

There will probably be policies in many countries restricting the number of kids we can birth to. Similar to China.

[@lilchamotamp221]

CHINA CAN SEE THE FUTURE..They are sending 10 thousand people to space...It's scary.

[@mrme1821]

HUH?? I think that I might have missed something.

[@casey6556]

Phelps has 22 gold medals, so if we have 250 000 times more, we have only 5.5 million. Shouldn't we have ~33.3 million times as many medals, given our current population?

[@ZVlog1120]

I'm taking ecology next semester. This series is going to give me a huge edge.

[@erictaylor5462]

7:25 That is assuming everyone lived on a flat plane. But as our large cities have demonstrated, you can fit a lot of people on that 12X12 plot of land. Just stack them up in a high-rise. A 100 story building could fit 100 people on that single 12X12 plot. And 100 stories isn't that high. The Twin Towers were 110 stories, and they weren't even the tallest buildings.

[@TristanBomber]

tl;dr: We broke the system

[@jnyerere]

Having gay people (who don't want children) also helps. Having career-oriented people who don't want to be "held back" by families helps.

[@marcopolo3001]

And in the near future, having photorealistic VR sex and android companions with smart AI will also help tremendously.

Birth rates are a problem in Europe and much in the world, but in the opposite way. The birth rates are far too low such that there are going to be some major issues with managing an aging population. Peak population is predicted in about 40 years (see UN stats by googling).

[@Mroma1228]

As controversial this episode might be, I think you barely evoke the main issue : consumption. If having more population imply using more space, it's mostly means using more resources, of which many are non-renewable. I see no problem having 15 billions people if they are vegetarian, recycle and don't buy as much useless stuff as the ''Western'' population do.

[@RYSEAmato]

+Mroma1228 ding ding ding! Winner right here

[@alvinjones6856]

+Mroma1228 yup...no computers and internet....

[@lizcth233]

Great point, except it's not either/or. We're very unlikely to reduce our consumption enough to overcome our continuing population growth. There's no reason to postpone population reductions until we dismantle capitalism, greed, etc.

[@earlgreytempest]

i like the black background much better then the patchy green one. less distracting.

[@beagamechanger4life927]

at 4:15 he is wrong he is actually talking about Louis Pasture not Antonie van Leeuwenhoek. There are some inaccuracies in your science facts. van Leeuwenhoek used the population of Holand and its respective landmass size to estimate the worlds population base on its landmass.

[@kaytobe]

It's not just women becoming more educated, it's also women having more rights over their own reproduction. That's an important point.

[@KrillinDay59]

Abortion is being fought for by females to be illegal. Plus feminists tend to have lots of double standards when it comes to "equality" so I can't really agree with you on that.

[@elifuller9]

Women have the right to abstain from intercourse; not to dismember a child that's half theirs.

[@normanflippingreedus]

2020 be like:

[@jayeshhonda]

Thank god I did not make this planet I am more advanced!

[@casdraws]

There is a really great TED talk about this that basically says the population will cap out. He also researched and found that religion had very little to do with it. Education, access to family planning played a bigger part in limiting population. Women and families were able to control how big their families were and better able to support their children. I think we'll all be just fine.

[@hannawestergren2804]

Hank, did you see Hanson Rosling's talk about human growth population? he concludes it will stop at 11 billion. it's a great talk :)

[@jamesmallon1631]

This might sound harsh, but the best people to 'go' would be the religious people, since they are so out of touch with reality as it is, and they all believe once they die they will go to heaven anyway... so they could make room for us more scientific minded people to help make the world a better place...

[@KASASpace]

That is huge generalization. Many of them aren't out of touch with reality. Many atheists are out of touch with reality as well... Some scientific people are religious people too. I hate generalizations like this. It's comments like these that are preventing the world from being a better place, which EVERYONE WANTS IT TO BE. Even the Theists of the world want it to be a better place. Stop making them waste time, and maybe they can help.

[@SuperOtakuKyo]

I wouldnt say they are out of touch they just have a certain(sometimes strict) belief in something

[@emilyhouse1036]

What an awful comment to make

[@jamesmallon1631]

Emily House I am not saying i want to see all followers of faith killed. I was just stating an opinion, that the world would be a better place without religion, and that scientific minds which are not held back by their religious beliefs are more likely to help move the world forward. Religion may have had some good uses in the evolution of man and civilisation but it sure as hell is not needed in the 21st century.

[@KASASpace]

James Mallon That's debatable. There's a difference between stating an opinion and stating an opinion as fact. Do you personally know all religious people? No, you don't. You are seeing the minority. A similar one exists within atheism. and atheism =/= scientific minded.

[@jamesmallon1631]

This is the most depressing topic ever

[@jamesmallon1631]

***** that is not as depressing

[@Kaitlyn-qo7bi]

Hey you! Yeah you! Cramming for the APHG Exam! Good luck! :)

[@still.rendering]

You are the reason I'm passing classes

[@Eddietheallrounder]

That first argument you gave depends largely on your definition of success. In Hank's context, I believe he is referring to success with regards to increasing our carrying capacity, which, as far as I know, has been done to a greater extent than any other species.

[@christianbolorinos7849]

Hank is the man! These shows are so informative...

[@isabellavaldes1959]

i would really love to see you talk about Human Geography im currently taking this class AP Human Geo. and would love to hear you talk about this subject matter . like so hank can see please !??!

[@hwork50]

I love your videos and showed this one today as we began looking at the Agricultural Revolution.

[@getslockedout]

Hank Greene, single handedly saving AP science students around the country.

[@raptorqu33n]

This is really helpful for my ap environmental final. Thanks!

[@hamtrio]

i've always been curious about the topic of human population. Thanks Hank for making it more clear!

[@jeremygarst394]

this episode reminds me a lot of Dan Brown's book Inferno

[@Spaceout626]

Dear Hank Green, You are the reason I am passing AP Environmental Science. Thank you, -A stressed-out high-schooler

[@HenrySims]

Good for both of you, I hope your grandchildren will be able to remember your golden years of your careers.

[@Pikazilla]

I think the carrying capacity is around 500 million, in the longrun. Remember that pollution and environmental depletion increases as population increases, and this sharp rise is fatal to human civilization. Not that we will all die the next day, but massive die offs do exist. Even if humans survive, which we probably would, hundreds of millions could die from whatever happens; most likely famine or disease.

[@EvilSandwich]

I don't think any laws for population control are necessarily needed quite yet. The culture in much of the western world and many parts of south east asia seem to be falling into the pattern of having only about one or two children per family. Not because of anything forcing them to, just the general idea that one or two is just more practical to have. Hopefully if this catches on in more parts of the world, human population should level off in the next 25 to 30 years. I'm an optimist, i know. But there is only so much I can do myself personally.

[@thetrilliantwin]

This man is incredibly intelligent and is merely reporting the facts about overpopulation. Please don't forget to be awesome.

[@marcovelliscig8601]

Great video! But would not be better to put some thought bubble graphics like in crashcourse history, just saying the black background and only one person speaking can be a little tiring for long videos.. Anyway I love this channel is very interesting!!

[@ardaisldar6758]

Germ theory disease was hypothesized and experimented first by Pasteur and then developed by Koch. Leeuwenhoek is the first person to build a microscope and observe microorganisms which he termed animalcules.

[@alvinjones6856]

+Arda Işıldar But sammelweis knew that basic hand cleaning could prevent childbirth fever...even the romans knew that smelly places had illness in them even if they didnt know that bactiria that caused the smell, rather then the smell, made folks ill

[@Tincuradan]

If you expand in all 3 directions at maximum you will do so at a rate of n^3 (where n is velocity, assuming it is constant) This rate will inevitably be matched and then overtaken by exponential growth. So even filling surrounding space with living stations will have to be complemented with tempering natural population growth to be within the limits. The upside of space expansion is that the growth of the carrying capacity is known, because engineered. It's no longer subject to speculation.

[@My-name-is-Kit]

The problem with using Honey Boo Boo as an example is that she is still from an affluent country with a mostly service-related economy. The positive feedback loop works when you apply it to rural areas in Latin American and African countries, for-example, where people tend to grow their own food. As for Bacteria, while they might outnumber us, I'd hardly call them more successful. Bacteria don't generally work to actively increase their carrying capacity the way we have.

[@corinnefloyd4036]

Ok but I think he was talking about the second agricultural revolution cause the first actually started in the middle east (mesopotamia) about 10,000 years ago. A long time after that, the second agr. revolution rolled around and out popped more effective farming, gmo's from that one dude who spent a long time in Mexico developing high yield seeds and all that, etc.

[@Modinthalis]

I don't know what we are disagreeing about now? Whilst the population is going up, birth rates ARE going down. As far as natural resources and whatnot (something I never actually talked about), it is relatively simple. If something cannot go on forever, it won't. We will adapt when some resource becomes scarce (what resources you are talking about I am not sure?)

[@EyeLean5280]

"...but I can guarantee that those people would have a hard time getting along with each other!" It's little asides like this that make me love crashcourse so.

[@snowpunk116]

I love these videos. I wish I could speed them up and slow them down like I can with the ted videos.