You can’t have this discussion when just talking about population alone. You must understand the situation in terms of population x consumption. I.e How many people at what living standard. If we had fewer people, they could lead richer lives. Conversely, having more people means fewer available resources per capita. Don’t go too far down this rabbithole until you get the bigger picture.

Then frame this discussion against a planetary boundaries framework. We live on a finite planet that has limits. Breech those limits and suffer terrible consequences.

8 billion ridiculously unequal humans such as we are have grossly exceeded several planetary boundaries. Any combination of population reduction and consumption reduction that gets you back under the planetary boundaries is the key to avoiding human extinction.

A billionaire looks at this math and says I can have more if I push more middle class into poverty.

An ethno-fascist says my people can have more if we kill those people over there.

The communist says if we eliminated billionaires we could raise the consumption of the lowest of us to escape poverty and bring overall consumption down.

My preferred option is degrowth. Fewer people by lower birthrates and lower overall consumption by focusing on the wealthy who have room to spare. It doesn’t have to be crazy radical. Outlaw private jets. Eat less meat and return some land to it’s most ecological sound production. Return some to wilderness. Make passive house and electric heat pumps part of the building code and end fossil fuels. Build urban, regional and national electric train transit and let EVs be for last low density last leg rural. Encourage telecommuting and work from home. Outlaw planned obsolescence and mandate repairability. End casual overproduction of pollutants like PFAS and ensure its use is limited to high value use only until substitutes can be implemented.

Eventually, hopefully earth can stabilize around 1 billion, healthy, happy people around the world who have their material and energy needs met, while earths planetary boundaries are respected. We could double the population to 2B. But we would have to halve our consumption. Few people want to live like monks, so I personally lean towards fewer people and higher resources per capita. A comfortable, modest lifestyle without extremes of rich and poor.

The good news is the worlds falling birthrates are a naturally occuring phenomena. We’ve outgrown our planet, and the scarcity of energy and wealth is causing people to rethink having children. Let’s accelerate this process and we have a chance to dodge some of the worst outcomes of our profligacy.

I’ll be honest, there is a reckoning coming because we’ve so badly overshot earths planetary boundaries already. Climate change is just one facet of the predicament. The consequences already baked in are severe. Like our friends over in /r/collapse are aware, a collapse is coming. How well we respond to this collapse will determine what the future of humanity is. Degrowth is a painful, managed descent back to sustainable levels. Collapse is the unmanaged, chaotic descent back to sustainable levels. The only real choice left to us is this dichotomy. Chosing any flavour of techno-optimism “green growth” b.s. is really just choosing collapse with extra steps. For degrowth’s benefits to really shine, it has to be intense enough to get ahead of the collapse curve.

Here is a thought experiment. If you were the benevolent supreme dictator of Earth, (impossible, I know), and you wanted to optimize for a return to sustainability how would you go about it?

For me, I would command that we plan for a rapid reduction of population. Radical degrowth in one generation aiming for a stable 1 billion diverse human beings. The current generations would be tasked with building the resilient sustainable world of the smaller future. It’s a lot easier now, because you don’t need to convert all legacy infrastructure and future growth to a sustainable one. You only need to build a resilient core that accomodates 1/8th of your former population. Take a city of your choice, build a resilient, efficient, futureproof passivehouse, electric, heatpump enabled downtown core. As the population declines, and suburban legacy homes and infrastructure become abandoned, instead of mining for new resources to feed the core, you can strip your suburban periphery for the copper, aluminum, brick and wood. Suburbs, in time will be stripped back to farmers fields and wilderness. A major occupation of the smaller 1/8th will be a permaculture farmer living in a passivehouse. Urban cores will contain the remaining scientific, technological and industrial capacity of humanity. It will be focused on maximizing the circular economy where waste streams are incorporated into product development.

No progroms, death camps or race wars required. Managed degrowth back to something that can last. The big hurdle of this is letting go of the old and infirm as a rapidly aging civilization can’t be burdened with taking care of so many elderly with so few youth. Legalize compasionate medically assisted end of life. Promote graceful exits and end the suffering of vegetative old who would already be dead if not for enourmous intervention to keep the meat going long past the mind’s expiry date.

This concludes my TedX talk. Thanks for listening.