Ask HN: Are there too many people in the world?
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.
http://www.bbc.com/earth/story/20160311-how-many-people-can-...
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).
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
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- 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.
I don't want to live in a tiny apartment. I want to live in a big house with a garage so I can start companies like Jeff Bezos.
https://en.wikipedia.org/wiki/List_of_countries_by_ecologica...
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.
Your question was the only question where I was stunned, talking to an older man who was ( a little) racist and a lot more.
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.
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..
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.
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.
My thinking is that history has shown that when humans exacerbate resources they shrink back/go away (ghost towns, abandonded civilizations, etc.).
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.
* 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?
Here's "Optimum Human Population Size" - GC Daily, AH Ehrlich, PR Ehrlich , from '94: (full text: 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.