
Ask HN: Are there too many people in the world? - kaycebasques
If this thread takes off it’ll probably get flooded with vague, emotional arguments, but I’m asking on the off chance that we get some unexpected perspectives backed by evidence.
======
chupa-chups
Relevant:

[http://www.bbc.com/earth/story/20160311-how-many-people-
can-...](http://www.bbc.com/earth/story/20160311-how-many-people-can-our-
planet-really-support)

My own opinion: i don't know the limit, but there definitely is one. And i'm
not sure if we're preparing for reacting the right way if that happens (or has
happened already).

~~~
shoo
That article focuses on climate change and per-capita CO2 pollution, making
the point that it isn't merely population size that is the problem, but
population size * per-capita environmental impact.

Climate change is the number one example of a planetary boundary that has been
crossed from the "safe operating space for humanity" into an unsafe zone
(Planetary boundaries, Rockström et al [1]).

One way of framing environmental impact is by the equation

    
    
        I = PAT
    

where I is environmental impact, P is population, A is "affluence" (measured
in affluence-units per capita), and T is "technology" (measured in
environmental-impact-units per affluence-unit) [2]. This equation is fairly
artificial in that it is an accounting identity, you start with I = I and pick
some variables to factor the right hand side with. But it gives one way to
start thinking about the problem.

Since this is hacker news, probably the factor people get excited about
improving is the T factor, labelled "technology" \-- i.e. reducing the
pollution intensity of each unit of affluence -- think energy efficiency etc.
Reducing the T factor is compatible with capitalism, compatible with a mindset
that all problems have a technical fix, doesn't require talking about
explicitly limiting anyone's freedom re: the P or A factors. On another hand,
just focusing on improving efficiency doesn't necessarily result in an overall
lower environmental impact once the whole economic system reacts (c.f. Jevon's
paradox [3]). If you reduce T maybe P or A shoot up, giving you a greater I.

On a small scale, if you sit down and crunch the numbers, and focus on a time
horizon of 100 years or so, you could ask which family & their descendants
contributes the most CO2 pollution:

(a) a family in a low natural population growth, high CO2-pollution society;
or (b) a family in a high natural population growth, low CO2-pollution society
.

At extremes, comparing e.g. (a) a couple from Australia (15.4 tons CO2/capita)
with (b) a couple from Bangladesh (0.5 tons CO2/capita), the environmental
impact of the relatively low-population-growth, high-per capita pollution
couple is FAR worse, even if you say that _all_ CO2 emissions of children,
grandchildren, great-grandchildren etc over the time horizon are attributed to
the original couple [4]. So in my mind, at least in the short run of 100
years, population isn't the concern, it's the population of individuals in
high-pollution countries with high-pollution lifestyles (like myself).

On the other hand, there's nothing really special about climate change, if
global human population continues to grow, if we figure out how to avoid or
mitigate climate change, the interesting thing to watch will be how we deal
with crossing the second global ecological boundary, or the third...

    
    
      [1] https://en.wikipedia.org/wiki/Planetary_boundaries#Nine_boundaries
      [2] https://en.wikipedia.org/wiki/I_%3D_PAT
      [3] https://en.wikipedia.org/wiki/Jevons_paradox
      [4] https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita

------
chobeat
No, there are just too many with a lifestyle way too consumeristic.
Eliminating the western lifestyle, especially the American one should be
enough.

~~~
idDriven
So we need to put more effort into building effective mass transportation to
help the populace achieve this goal right? I mean I agree, I visited London
and want the US to have an equivalent mass transit system, in most of the US
you cannot find work if you don't have a car. These are hard things to modify
at the individual level though.

~~~
beatgammit
That's a fairly small part of the problem. Think of all the other stuff
westerners take for granted:

\- plastic wrapping on goods \- frequent replacement of electronic devices \-
rapidly changing wardrobe \- waste inherent in eating out \- large quantity of
meat in diet

The western lifestyle is _far_ more expensive than, say, African or central
Asian lifestyles. We consume far more than other cultures.

Improving mass transit would certainly help, but the crux of the issue is that
it's a culture issue.

------
idDriven
So this was an interesting book, well written and using empirical evidence
that humans are killing the planet:
[https://en.wikipedia.org/wiki/The_Sixth_Extinction:_An_Unnat...](https://en.wikipedia.org/wiki/The_Sixth_Extinction:_An_Unnatural_History)

I tend towards the view that this book is accurate, simply because I read a
lot. When you read explorers accounts hundreds of years ago you have sea and
land teeming with life and biodiversity. Now, when you watch a reality TV show
like 'Naked and Afraid', there is very little to no wild animal life, the show
should be called show up and starve.

------
NicoJuicy
If not now, probably soon: [http://www.worldometers.info/world-
population/](http://www.worldometers.info/world-population/)

Your question was the only question where I was stunned, talking to an older
man who was ( a little) racist and a lot more.

------
a-saleh
The model I am used to is the
[http://www.footprintcalculator.org/](http://www.footprintcalculator.org/)
despite the fact I don't really know what is behind the data.

It postulates, that if everybody would consume/travel, we would need two more
earths to sustain that.

On the other hand, I heard that most of the big population bump were families
still used to having 5+ children, because most wouldn't survive childhood, but
medicine being just good enough to save them all. We no longer should have
bumps of billion per decade as in the beginning of 20ct.

------
mchannon
I'm going to go contrarian and say no. There need to be more.

Before I get ecoterrorists looking up my home address, let me state that the
planet's gas balance and biodiversity are unequivocally getting thrown way out
of whack by the impact humans have and are having. Given how the plurality of
human beings are subsistence farmers who aren't really moving the needle much,
beaming them all to a faraway planet just for the "too many people" problem
would have almost no positive impact on the planet. We could do bad all by
ourselves with less than 1 billion on the planet.

If you therefore treat the impact to nature as a separate problem, then
exclusive of that, people are a good thing as far as other people go. There
are limited physical resources, but social resources push the balance the
other way. Humans need other humans to survive. Scale back America to 30
million people, and think what would happen to our comfort level and
technological innovation.

Having less people to justify your own existence through selling your own
products or services takes a lot away from you. Imagine losing 9 out of 10
choices at the store.

It's hard to see the benefits other people give you when you're staring at an
ocean of them on the 101, or waiting until your group number to board, or
waiting for your reservation at the local brasserie. But without them there'd
be no 101, no airport, and no local brasserie.

And if you're single, if you thought finding Mr. or Ms. Right was difficult
before..

------
muzani
That is probably the wrong angle to look at it. It's more that individual
humans are contributing less, and they cause too much harm.

For example, we can trade labor for money and money for wood. So we create
great logging corporations who try to chop down as much wood as possible. At
some point, the demand for wood drops, so we start creating more wooden
products, marketing toothpicks, or selling cheaper cardboard boxes. Later on,
some meal box startup decides that the price of cardboard boxes is so low that
they can send a meal box every day.

Housing prices have not 'gone up'. In fact they get a little cheaper as people
have better house building tools, and the raw material costs are about the
same. But the average person produces less average value, and struggles to
produce enough value to trade for a house.

Maybe a big part of this is that all this automation technology really has
made people less useful. Inflation and overhiring masks the fact.

~~~
kypro
Doesn't the value of a house have less to do with how much it costs to build,
but how much the land it sits on costs?

My understanding is that if you have a growing population whom all wish to
live in a few major cities then simple supply and demand means house prices in
cities will raise unless more supply is added to the equation. But then in a
city like London or New York the only place you can build is up (or down in
the case of London) so this isn't always feasible.

House prices in rural areas are fairly affordable.

------
croo
Hans Rosling has ted talks about the topic ( why wont world population exceed
11 billion, or something similar - he has a lot to say about this in multiple
videos). It is backed by statistical evidence.

------
tmm84
I don't think as of this moment in time there are too many people in the
world. However, the problems of work/food/water/housing seem like a population
problem but it is more of a resource allocation problem. I think humans have
proven we are bad at resource allocation/management when money/status
influences it.

My thinking is that history has shown that when humans exacerbate resources
they shrink back/go away (ghost towns, abandonded civilizations, etc.).

------
BentFranklin
Say what you want about Ebola, it's one of the few things that could actually
halt global warming.

~~~
kypro
How come?

------
Dinamic_Tech
I think this is not about the number of people, but more like there are too
many people on earth with different values and a mindset that they do not
agree with other peoples values/beliefs and try to change that. That is where
all the wars and stuff comes from

------
perilunar
Too many people on Earth, not nearly enough people in the rest of the solar
system.

------
BjoernKW
That's the Malthusian hypothesis, an assumption that has been repeatedly and
consistently disproven since it has first been formulated more than 200 years
ago.

Strangely enough, it's still surprisingly popular.

Groups like the Club of Rome and reports such as "The Limits to Growth" often
don't state so explicitly but when you assert that artificial limits should be
imposed on economic growth you're basically making a decision about which
human beings get to be born in the future.

In my opinion that's a both patronising as well as deeply anti-humanistic
notion that doesn't take into account that there have always been and -
extrapolating from the past - likely will still be paradigm shifts in the
future which will allow us to make both more efficient use of existing
resources and to discover new types of resources or new avenues for extracting
existing ones.

------
tomjen3
By what measure? Surely there are useless people, but we can feed the entire
world, so why not?

~~~
amibang
* If I don't have a large house with garage,

* If I don't have a car,

* If I have harsh restrictions on when or how much electricity I can use,

* If I can't move around at night for fear of disturbing housemates or neighbours,

it can be difficult to start certain kinds of ventures.

Getting rich or starting a successful business is really what I'm living for.
If I had to be a wage slave forever I'd off myself right now so that my
corporate paymasters would no longer benefit from my labour.

Is having as many people existing as possible, really what we want to optimise
for? What about optimising for freedom or quality of life?

------
codevark
Studies have estimated that the ideal Earth population, living sustainably at
an average Western standard of life, would be less than 2BN people. The
numbers vary, but the suggested populations are all well below the current.

[https://en.wikipedia.org/wiki/Optimum_population](https://en.wikipedia.org/wiki/Optimum_population)

[https://www.youtube.com/watch?v=neGdoqsuiN8](https://www.youtube.com/watch?v=neGdoqsuiN8)

~~~
shoo
The question of "optimum" global human population is an interesting one.

Here's "Optimum Human Population Size" \- GC Daily, AH Ehrlich, PR Ehrlich ,
from '94: (full text:
[http://dieoff.org/page99.htm](http://dieoff.org/page99.htm) )

> All optima must lie between the minimum viable population size, MVP [...]
> and the biophysical carrying capacity of the planet. At the lower end,
> 50-100 people in each of several groups, for a total of about 500, might
> constitute an MVP.

> Above the minimum viable level and within biophysical constraints, the
> problem becomes a matter of social preference. [...] Human population sizes
> have never, and will never, automatically equilibrate at some level. There
> is no feedback mechanism that will lead to perfectly maintained, identical
> crude birth and death rates. [...]

> 1\. An optimum population size is not the same as the maximum number of
> people that could be packed onto Earth at one time. The maximum would have
> to be housed and nurtured by methods analogous to those used to raise
> [battery] chickens, and the process would inevitably reduce the planet's
> longterm carrying capacity. [...]

> 2\. An optimum population size should be small enough to guarantee the
> minimal physical ingredients of a decent life to everyone [...], even in the
> face of an inequitable distribution of wealth and resources and the
> uncertainty regarding rates of longterm, sustainable resource extraction and
> environmental impacts. We agree with Nathan Keyfitz (1991): "If we have one
> point of empirically backed knowledge, it is that bad policies are
> widespread and persistent. Social science has to take account of them."
> [...]

> 3\. Basic human rights in the social sphere [...] should be secure from
> problems generated by the existence of too many people. Everyone should have
> access to education, health care, sanitary living conditions, and economic
> opportunities; but these fundamental rights are difficult to assure in large
> populations, especially rapidly growing ones. [...] Democracy seems to work
> best when populations are small relative to resource bases [...]

> 4\. We think an optimum population size should be large enough to sustain
> viable populations in geographically dispersed parts of the world to
> preserve and foster cultural diversity. [...]

> 5\. An optimum population size would be sufficiently large to provide a
> "critical mass" in each of a variety of densely populated areas where
> intellectual, artistic, and technological creativity would be stimulated.
> [...]

> 6\. An optimum population size would also be small enough to ensure the
> preservation of biodiversity. [...]

Ignoring the question of what an "optimal" population size might be, it seems
reasonable to attempt to clearly state what criteria we'd use to try to make
some kind of decision.

Some other criteria that are not included in the above list could include:

* individuals prefer to have freedom about if/when/by-how-much they reproduce. On the one hand many people don't want to have individual freedoms limited by society or government, although these freedoms might be incompatible with other objectives such as assuring a minimum level of human rights for the whole population. On the other hand, some individuals do have access to additional freedoms or options provided by society: access to contraception, IVF, etc.

* some countries with growing populations & economies are run like some kind of demographic pyramid scheme. Regardless of what an "optimal" population level might be there will be a lot of push back from people in positions in power who don't want to change the status quo.

------
Zelmor
Yes.

