Most of the „western“ world expects shrinking populations within the next two or do decades. Even huge countries like China aren’t expected to grow anymore.
Based on the data I am aware of, overpopulation won’t be an issue. The shrinking populations however will be an issue considering they’ll have a huge impact on the countries social systems and ability to produce basically anything
Indeed if the total capacity of the earth was, for example, 2 Billion people, the birth rate could be declining or even 0 for quite some time and we would still be overpopulated.
What "overpopulation"?
Humanity has creted-over, and will be dramatically smaller (globally) in population in the next ~50 years.
China, for example, is projected to drop by ~50% before 2060.
Population shrinkage could be a huge socio-economic problem worldwide, if measures are not taken soon to address it! Countries that employ pyramid schemes to handle older generations' care (a la the US' Social Security) are going to have som major rethinking to do if they plan to keep programs running that were built on the presumption of steady population growth!
A reduction in population would have immediate benefits: less manufacturing, less energy use, less pollution, less consumption, more land available for wildlife instead of stock/agricuture.
But what that means is "no growth" and "less money", which is not a popular concept in economics, politics and wealthy people, and they largely set the discourse.
It's been said that we're the only species that won't save itself because it's not cost effective. Damn right.
Some might argue that high consumption patterns along with high emissions and high resource demands all add up to a high debt which is exceeding planetary recovery boundaries.
Some in fact do make that argument.
The former is a metric of how comfortable your life is; the latter is a complex metric of energy production and surplus, food per acre and inputs, etc. and how sustainable it is (which, at the moment, it isn't).
But we're running at about 200 species extinctions per day. Every animal on the earth has detectable levels of PFAS. You have microplastics in your body and DDT in your adipose tissue. We all do. We're cooking the atmosphere and boiling the seas.
But yeah, enjoy your standard of living.
> The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment.
In other words, we’ve exceeded the carrying capacity of Earth because our current practices cannot be sustained over a longer timespan.
Your comment makes me wonder if it is indeed about “save the planet” without scarifying “growth” is what most people care about.
It is beyond obvious that the best single thing that an average individual can do for the climate is to have 0 kids — the next best thing is to have fewer kids.
Anyone who doubts this is mostly justifying their lifestyle choices (or will think they’re supremely clever for suggesting suicide as being better). Which is fine. Climate is fucked if they have 0 kids or 10 kids. Doesn’t matter a lick at this point.
The good news is that for nearly everyone wealthy enough to be on HN the bill mostly won’t come due until it’s your kids’ kids or kids’ kids’ kids lifetimes.
All that aside, I think this is the paper you’re talking about:
For example, when food is low, food prices go high, and people just stop having babies. It was also a time when people thought poor people in africa will just have kids because more kids bring in food. But having lots of kids still makes sense where there's land for subsistence farming and such. Having more kids in places like, say, Singapore wouldn't work because there's no land for food. In these places, poor people just choose not to have kids.
When people talk about there only being a fixed quantity of some resource "available," they almost universally mean "accessible." But the definition of what's accessible changes over time as prices rise (making it economical to extract harder to reach/refine resources). There's enough power from the Sun and resources in the solar system to support hundreds of trillions of humans.
Nowadays, in large parts of the world new births a decreasing much faster than modern medicine is advancing life expectancy.
Look at charts showing birth rates of Germanys births, it’s below replacement since the 70s. Similar effects can be seen for other countries are in a similar situation
As emerging economies develop, the birthrate plummets.
We've seen this time after time. We're highly confident that the asymptote is understood. Global population trends have been studied for centuries.
Peace reduces birthrate. Longterm. Short term sure there is a post war baby boom. Don't mistake local issues and trends for longterm demographics.
Simple - replacement births are simply not happening
Human life span is approaching its [medically-enhanced] limit
And women, quite frankly, are - in gestalt - not having enough babies to keep population rates growing ad infinitum
There are exceptions to the rule ... but - globally - birth rates are below replacement level.
Birth rates are a tailing indicator, but they are still there.
Though perceived views of humanity and overpopulation and the alleged benefits of reduction are the narrative
The problem is the delay. Europe is doing 4 day work weeks because the workforce does not match and some countries do 6 days because they have excess workforce. But workforce can be 20-30 years out of sync with the current state. It's why immigration/emigration is a good thing too.