I kinda went on a little research spree on economics this afternoon but at one point I figured it’s probably good to know if it’s possible for, say, at least 98% of people on earth to live a happy fulfilled life at all.
I know there’s plenty of people who’d be more than happy to have literally nothing more than a house, food and water, but that still leaves a whole lot of people who want other things in life.
Do we have any metrics or data on wether the earth can sustain roughly 8 billion humans?
They key to your question is “sustainably”. We can support 8 billion humans without poverty for a time. We can support 10 billion for a shorter time. There is no way to support 8 billion sustainably.
A sustainable civilization uses zero fossil fuels, and recycles 100% of metals and engages in virtually no mining. Our civilization enjoyed a energy metabolism based on fossil fuels with an energy return of 100-1 in early 1900’s. That spawns phenominal growth and automation. The easy oil is gone now, so we’re living on 20-1 EROEI and declining quickly. Renewables give a roughly 3-1 eroei. Think about all the things civilization will have to prioritize to live on a 3-1 metabolism. Monster truck rallies, NASCAR and Jetset NBA teams flying around the country eating beef hamburgers served via drive-thru (sic) to your SUV is gonzo.
A sustainable world leaves 50% of land in a state of nature, untouched by human hands to preserve biodiversity. The number 1 occupation is permaculture gardiner/farmer and we live in ultra low energy passivehouses. Everyone eats local and transport of goods is done only by sail. No more fossil fueled powered combine harvesters.
As our micro and nano plastics crises is showing us, we would have to give up synthetics like polyester for clothing. Whatever population we have would be wearing cotton, wool, hemp and leather or their birthday suit. No more single serving anything.
I could go on, but you get the idea. How many humans can be supported depends on the consumption of resources allowed by society and the equality permitted within that society. There is no exact number as there are a ton of variables.
A mostly equal society living a comfortable but austere lifestyle could probably support 1 billion which is roughly dialing back life to before the industrial revolution. Say 1800’s While the planet is much degraded since then you could argue the number is much lower, but we have a lot more knowledge and skill today about chemistry, medicine, sanitation etc.
At the same time, are we still running MRI’s in modern hospitals? What kind of pharmaceuticals can be run sustainably when your average person is a permaculturist farmer. There will naturally be some specialization. Will we choose doctors or soldiers? Do we have a militaries and political factions? That will consume an enormous amount of our sustainable energy and materials budget, thus fewer lives can be supported withing your sustainability budget.
In my personal opinion, 500 million or less would be optimal.
When life gives you a lemon, go to the store and buy more.
Awful lot of resources out in those asteroid belts. Put up a Lofstrom Loop, then a skyhook, then an orbital ring. Then you’ve got a whole solar system’s worth of resources.
I agree that the Earth should basically be managed as a wildlife preserve / population center. But you’re missing that we’re not limited to the resources on Earth.
Wait, so in a drive for sustainability, you want to fight gravity with $10,000/kg spaceflight? (Using expensive rare metals, computers and fossil fuel.)
If we need resources beyond earth? Is it sustainable in any sense of the word?
No. I want to fight gravity at $100/kg. Hence the megastructures.
I’m fairly certain that with the resources of an entire solar system on tap, the word ‘sustainable’ takes on a new meaning. If we use few enough resources that they won’t run out before the Sun explodes, does it matter that it’s not net zero?
We’re sustainably building megastructures too? How is that done exactly?
Fairly certain you’re being intentionally dense, but I’ll respond in good faith here:
I already told you the megastructures I want to build: a Lofstrom Loop, then a skyhook, and then an orbital ring. Wikipedia has good descriptions of each. Each would make getting mass into orbit much easier, so you start with the smallest to simplify the larger ones. The Lofstrom Loop would likely cost $10-$30 billion, and reduce cost/kg to a few hundred dollars. The skyhook and orbital ring would be orders of magnitude reductions. With the orbital ring up, we could literally winch payloads up to 80km, ship it around the Earth on maglev, or launch it off to other parts of the solar system - all powered by solar panels. If that’s not ‘sustainable’ in your eyes, I don’t know that further discussion will be productive.
Finally we agree on something.
What is the energy, emissions and materials costs of megastructure construction and maintenance? Where is this surplus coming from considering we’re already in deep ecological overshoot.
How do you get back within the planetary boundaries limits when people are still trying to grow and expand and accumulate resources.
Sci-fi handwavium is ridiculous.
We can definitely support the current population sustainably. The issue has never been resource shortage, it’s resource distribution.
Well, the main issue is profits, and equitable distribution of resources isn’t profitable.
Respectfully, no we can’t. Not even close. Take away the fossil fuels and put civilization on renewables and biomass and see how many people you can support.
Incorrect. The issue is about sustainability - meaning you have to halt pollution, climate change emissions, resource consumption and land and water use and protect biodiversity to what can be renewed by natural processes indefinitely.
Take away fossil fuels and pesticides and herbicides and watch agricultural yields and yield density drop significantly. Are you pumping groundwater faster than it’s being replenished? That too must end. How are you distributing this food to 10B sustainably? Ending soil erosion means permaculture where mechanization virtually ends. You also have to give back vast swaths of former farmland back to nature to protect biodiversity.
Your take is well meaning, but impossibly naive.