The much more likely is life just gets really bad for a while or at the outside possibility things fall apart enough we slide back a few centuries in some industries. If we go too far back power becomes an interesting issue because we've exploited most of the cheap easily accessible power sources so successor civilizations won't have the easy coal deposits to power a second industrial revolution.
More people is more good
Everything exists within the boundary conditions of its environment. Humans, just like any other organism, can strip its environment of resources faster than it can figure out how to escape the environment or build a new one or whatever.
We went to the moon in 1969. The last moon landing was 1973.
The world population in 1969 was 3,625,680,627 [0]
The world population in 2020 was 2020 7,794,798,739 [0]
Today's world population is 8,029,731,569 [1]
We've more than doubled the world population in the 50 years since the last moon landing and no country has ever yet made it back.
Using your argument, I can unequivocally say that more people is bad.
In 1969, there were 324.23 ppm carbon in the atmosphere. Today, there are 416.43 ppm carbon in the atmosphere. [1] This does not even count species mass extinction, other pollution, etc. Even in 1969, there were sufficiently massive real environmental damage concerns to create the EPA within the same presidential administration.
This also does not even mention the massive resource constraints and conflicts that inevitably arise with overpopulation. this includes oil, water, lithium, rare-earth minerals, and possibly most important, phosphorus, which is rapidly running out, and when it does, the entire agriculture industry that feeds the current overpopulation will crash, along with the human population.
Humans would thrive with something like 1/8 of the population, especially with the level of technology, and will continue to advance.
Just consider that a miniscule 6.7% of people have a college degree [2]. That provides something resembling an upper limit on the set of people actively contributing to technological advancement. Interestingly enough, double that is about 1/8 of the population.
The view that "some is good, more is better" is just... to be kind, massively simplistic and wrong.
[0] https://www.worldometers.info/world-population/world-populat...
[1] https://www.worldometers.info/world-population/
[2] https://educateinspirechange.org/how-many-people-of-the-worl...
Isn't that a bit like wanting to only take in high skilled immigrants without wondering where they're going to get their favourite food from home (which as a high skilled immigrant, I can tell you, food is immensely important to us).
We don't do this stuff alone, we need haircuts, streets cleaned, trains to run, people to make and deliver food etc. We all contribute.
So, let's take a look at food - and some data.
Only 150 years ago, it required over 70% of the population to produce enough food for 100% of the population. Today, it is under 5% in rich countries, and about 65% in poor countries [0].
Obviously, given the uneven distribution of technology and knowledge, those people are today contributing to society.
But it is also true that fully distributing modern agricultural technology will make entirely redundant (to the maintenance of a technologically advanced society) something like half of the world's population.
And that is just an example from one industry.
The point is that declining replacement population does NOT automatically mean that the technological level of society will decline.
Correlation is not causation.
If anything, population increased as a result of technological advance — ability to generate more food, better shelter, better medicine — technology was not the result of greater population. Once we have the technology, evenly distributing it will require far fewer people to build and maintain it.
Let's take it a step further, and say we want to avoid using massive amounts of fertilizer and pesticides common in modern agriculture. That will STILL not require the same amount of people slaving in the fields. The technology that will enable scaled-up organic farming is also massively labor-saving — agricultural robotics, not only planting and picking, but most critically monitoring for and eliminating weeds and pests [1,2].
Yes, there will be a greater need for people fabricating and maintaining agricultural robots, but that will be dwarfed by the number today's slaving-in-the-fields-jobs that will disappear in a near future decade. If they do not reproduce at full replacement rates, we will still have a society that has both technological workers, and others who contribute much more to the culture, including authentic cuisine.
[0] https://ourworldindata.org/employment-in-agriculture
[1] https://www.smithsonianmag.com/innovation/five-roles-robots-...
[2] https://www.ieee-ras.org/agricultural-robotics-automation
These can be linked, though. I have a lot of young people around me who are hesitant to have kids because of climate change and the period of instability their offspring would be born into. If we manage to address climate change, people may well enjoy the prospect more again.
According to what I read in the IPCC reports, we already have those; it's how goals like ones under the Paris Agreement get derived. I'd imagine it's a mix of footprint monitoring to see if we are hitting targets, and updating models based on new knowledge.
The bottom line is that a lot of people have a sense of "we're doomed" these days that's at odds with having the energy to make plans for a long-term future, or to look forward to it. If we improve I'd hope the collective zeitgeist would shift accordingly, and give those people a better outlook.
My own point of view is ... tricky. I'm relatively wealthy and well-educated. Privileged, really. My kids would be among the most likely to be in a position to contribute to a better world, so maybe having kids is the best ticket to keep the world going. I feel like I should invest the resources I have been lucky to get into family and children. I'm nervous if they'd grow up to agree, however, because this is easy to think while living in relative peace and comfort.
A 33% reduction in the population of one country is a tiny step in the right direction, but still far short of making a significant difference.
Applying even current levels of intelligence and knowledge (nevermind projecting even hints of the growth rates over the last ~10K years since agriculture, writing, etc. started), that is more than sufficient to develop resources for interplanetary and interstellar travel.
What unites both questions of sustainability of the environment and of population is the question "what, other than money and its getting and spending, are we for?"
It's not a merit based society. Even if someone wants to do things differently it's almost impossible to push for it.
Not necessarily. Only a small proportion of the general population "does innovation". In fact, automation and boosting productivity may mean (even should mean) more people doing high-value, innovative work.
> and markets that start getting smaller
It does not matter if a market gets smaller by number of consumers if total population also reduces and individuals are better off.
For instance, smaller population means smaller construction industry but also likely fewer builders. Does that imply that a builder will be individually worse off than now? No. They could even be better off if productivity increases drastically.
Everyone's decision to have children or not is individual, and should be addressed as such.
Population decline from things other than catastrophic events is not necessarily a bad thing.
Have you seen what life in Tokyo looks like for the average person today? The size of apartments, the crowds on subways, etc.
People's quality of life would be far better if the population density were lower.
I'd much rather have a world with a steady or shrinking number of people and a rising quality of life, than a world with an exponentially growing population and declining quality of life.
As for the reason for Canada’s birth rate woes since 1972, it was not socioeconomic (it’s likely due to declining male fertility). Abortion was only legalized in 1988 in Canada. Housing was affordable during that time and its economy was strong during the long period of consecutive population declines. Of course, like many countries a large portion of Canada’s population, including liberals, are now against immigration due to a combination of housing woes and a healthcare system in turmoil. Unfortunately, Canada has no choice unless they want to see their economy further crater and not have the working adult population to pay for socialized programs such as healthcare. According to statscan, Canada’s NIST, even if they drastically increase immigration; it will only slow down the age population bomb and not prevent it i.e. Retired elderly will still eventually outnumber both working adults and children one day too soon. The speed will likely accelerate due to the Canadian public’s growing distaste for immigration.
Japan will probably lead the way, but I'm confident we can create societies that thrive and shrink.
And if not, I need to see some real hard proof why shrinking has to hurt actual people, instead of using "economic growth" as a goal by itself.
Lower Workforce participation means people working more For Less personal reward. It also requires a transition away from using that too fund governmental function. Most governments use GDP growth and a higher future tax base to negate the fact that spend more than they receive.
In terms of impact to real people, this means adjusting to life with less material wealth. This doesn't just mean fewer trinkets, but also cuts to social Healthcare and welfare spending
I find that hard to believe.
That said, with all things being equal I would expect austerity simply because you have a smaller and smaller percent of the population working