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Abelard Bronfman's avatar

I’ve been telling people this for decades, with little noticeable effect except to enrage some. One point I’ve used has been similar to this, though not as well explained or supported, so thank you.

But my main point has been that the groups still growing in numbers by population increase already have tiny per capita carbon footprints. They are either extremely poor, as in urban inhabitants of favellas, etc. or are fairly poor farmers who in order to survive must put at least as much carbon back into the soil as they take out. The people with large carbon footprints—the richest few percent—are either not growing in numbers through reproduction, or are actually shrinking already, like Japan, where the rate of decline is a financial and labor demographic problem.

The point is well-illustrated by Oxfam’s mushroom-shaped graph showing percent of emissions by decile group. (“Before You Eat the Rich, Check the Menu: Assigning Blame for Climate Catastrophe” This Is Not Cool, June 16, 2023)

The richest 10% emit as much as the poorest 50% or so, and wealth and therefore emissions are increasingly concentrated among an ever tinier group.* For example, about a decade ago, the richest 10 people in the world together owned as much as the poorest 50 countries together; now it’s 3 people. A lot of what’s owned emits carbon and other pollution and in a civilization based on too many non-renewable resources, uses up resources.

As George Monbiot has said, ”The rich can relax. We just need the poor world to cut emissions. By 125%.”

* Chancel and Piketty agree:

Kevin Anderson, “A succinct account of my view on individual and collective action”

“It’s a consumption issue, not a population issue. Population is a complete red herring in regards to 2°C budgets.” Prof. Kevin Anderson

Going Beyond "Dangerous" Climate Change London School of Economics and Political Science (LSE) 43:50

“Wealthier people produce more carbon pollution — even the “green” ones:

Good environmental intentions are swamped by the effects of money.”

By David Roberts Dec 26, 2017

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Abelard Bronfman's avatar

Certainly we should do the things mentioned that reduce population—for climate, other ecological and many other social and political reasons. The only non-tyrannical, non-traumatizing ways to reduce population growth, and population itself, faster & more controlled & fairly than it's already happening, are to emphasize equality, empowerment, and education for all, especially women; and ensure security for all in sickness, old age and hard times, along with free access to contraception and all family planning services. IOW, the progressive agenda, here and abroad. All of which conservatives fanatically oppose.

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gregvp's avatar

The point of decarbonisation is to leave a habitable world to our descendants.

To do that, we must *have* descendants.

An aging world, besides, is one that has no money to invest in decarbonisation. All of its money will go into pensions and healthcare for the elderly.

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Moshe Koval's avatar

I'm not planning on having descendants, and I still want to leave a habitable world for all of the sentient beings living in it, including humans. I can make an argument that even if all animals were wiped out, a beautiful planet is worth saving for its own sake.

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Rosanna's avatar

Well said and to the point!

And to highlight the first comment; the places where the population is growing are those who have a tiny carbon footprint (here, education would be key).

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Matt Ball's avatar

Love your conclusion. Educating girls and empowering women to make their own choices is excellent, in and of itself. Indeed, it might be the single best thing that is within our control - funding efforts that advance the freedom of girls and women. Each of us can help with that.

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Kevan Shaw's avatar

One problem with the paper is the assumption that the population uniformly produce 4.5 tons CO2 per year. This is manifestly not the case. The urban population produce far more as do those in the wealthy global North. Increasing population increases the per capita energy use and general resource use as resources become more difficult to obtain then energy use increases again per capita. Climate change is anthropogenic ergo more people more climate change. I do not disagree that other measures are needed in the short term however population of humans already exceeds the earth’s capacity to the detriment of all other species.

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Nigel Southway's avatar

Its the reverse... NetZero will lower prosperity or slow it and this will drive population decline.

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Mal Adapted's avatar

"[Open-ended global warming] will lower prosperity or slow it and this will drive population decline."

FIFY.

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Buzen's avatar

Poverty has been steadily falling as surely as CO₂ and temperatures have been rising, so those appear to be inversely related, whereas birth rates have been steadily falling, so I don’t believe your “fix”.

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Paul Marx's avatar

Thank you for publishing this. I wrote a letter to ERDA about energy use back in the 1970's, when energy-efficient appliances were the vogue, but our older, more inefficient appliances were still being exported. I made the point that energy use per capita would grow faster than population as more countries modernized, expanding their use of electricity. I suggested that to reduce pollution (I lumped carbon in with all the other airbornes) we needed to help other countries to leapfrog transitional technologies so that the whole world would more quickly be able to reduce its use of carbon-based fuels. Needless to say, the leapfrogging hasn't happened very often, and the US has not slowed its per capita use of carbon-based fuels.

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Robert Hargraves's avatar

The headline is correct, but there is a related issue of prosperity per capita.

Just raising electricity consumption in developing nations to EU levels will double world power demand of 3,000 GW, or ~30,000,000 MW-hours per year. At 1 t-CO2 emitted per MW-hour, that's another 30 Gt-CO2 (gigatonnes) emitted per year.

That's why we need full-time low-cost nuclear power to help poor nations while checking CO2 emissions. The prosperity of electrification cuts birth rates, dropping in many areas but not poorest Africa. See ThorconPower.com about nuclear power in SE Asia.

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Ugo Bardi's avatar

Hannah, hello. I keep following your blog, and thanks for your Interesting posts. This is one of them! Excellent post, but excuse me if I disagree with you about your conclusions. You are missing something, just like the authors of the papers you cite. Population decline cannot be seen in isolation. It generates a series of negative feedbacks that reinforce each other. The final result is not the slowly declining curves you are showing. It is what I call the "Seneca Effect" which takes these feedbacks into account to show that the decline is much faster than growth. Several dynamic studies show exactly this effect, I discuss this in my upcoming book "The End of Population Growth." In short, population decline will have a much stronger effect on emissions than what the scenarios assuming a slow decline predict. That may be good for climate, but not good for us. The decline may be harsh and painful. Long story, some of my thoughts can be read in a post of mine.

https://senecaeffect.substack.com/p/the-coming-population-collapse.

Thanks again for your excellent work!

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Stacey Collins's avatar

Mike Berners-Lee in "There is no Planet B" says "A bit more growth can be tolerated provided we distribute it properly. Since the impact that each person has depends so much on how they live, it is clear that 1 billion reckless people would trash the planet in no time whilst 15 billion very careful people could live in harmony with a thriving environment. The more people there are, the more careful each one needs to be. [But] we will need to distribute the resources to the people. So, either the people are going to need to move to where there is sufficient food and energy production, or those resources are going to have to flow to them. Specifically, we have seen that existing agricultural production can feed the projected 9.7 billion people in 2050, but that only works if a lot of food grown in North and South America flows to Africa"

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Gary's avatar

"A bit more growth can be tolerated provided we distribute it properly.” Who gets to determine what is “proper?”

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Hunter's avatar
19hEdited

There is another subtle economic reason for why lower populations won’t reduce climate change.

Shrinking populations will decrease investment in new energy infrastructure because (1) less future demand for energy makes new infrastructure less profitable and (2) because a smaller working age population makes labor costs significantly more expensive.

But existing energy infrastructure is much dirtier than new energy, so via this mechanism, lower populations would generate slower energy transitions, which would ultimately increase total emissions.

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Shift2Lean's avatar

Good overview! It all comes down to economics as suggested. It has always been the case.

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Jay Roshe's avatar

In my field, medically targeting the biology of aging to address age-related ill health, people often consider the extreme of indefinite healthy lifespan and assume the population would explode with devastating effects on climate. This post is very pertinent to that, and it relates to how surprisingly small of an effect the extreme of even indefinitely healthy lifespan would have on population. Andrew Steele made a good video looking at estimates: https://www.youtube.com/watch?v=f1Ve0fYuZO8&t=275s

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Jason S.'s avatar

Point taken on footnote 3 but it still inclines me not to get caught up in the fertility fear-mongering. There will downsides to a naturally declining human population but huge upsides to land use and animal welfare.

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Donald Cheeseman's avatar

We missed our first deadline. Unfortunately, missing means that the poorest people on the planet are going to die unnecessarily. If we had responded justly 60 years ago when we discovered the climate problem. …

There is still hope. At least for the projected survivors, until the next deadline. In any event, there are going to be some changes around here.

I believe the Olys are building lifeboats. If I was a selfish, paranoid mega-man, I would. I would not spare a single thought to any one who could not demonstrate their allegiance to me.

We would have acted responsibly, if we had slowed and reversed birth rate through natural attrition and birthing fewer babies.

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Ryan K. Rigney's avatar

Incredible work as always, Hannah. This is SUCH an underrated blog.

I have a sort of goofy question: given that 1) “speed of decarbonization” seems to be the most powerful lever we have, and 2) prices for renewable energy seem to fall exponentially with increased production… is driving up demand for energy with things like big data centers potentially helpful in the sense that it would accelerate the energy transition?

Maybe another way to ask it (plugging in made-up numbers) would be: if we increased energy use by 20% today, could we get the energy mix to include double the renewables twice as quickly?

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Jason S.'s avatar

Helpful or not it’s happening. On Twitter you’ll find people making the case that it might indeed drive a lot of solar, wind and battery deployment resulting in lower per unit costs.

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Chris Fehr's avatar

Perhaps not so scientific but I can only observe energy demands going up around the world. Non carbon sources might be keeping up with increase demand but not replaing existing carbon sources. Now as people in already hot areas become wealthier they will consume more energy just like the already wealthy areas, namely air conditioning and cars.

At some point more of parts of the world just won't support the populations they have and that could be very traggic. This might be a good justification for easing back population.

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Buzen's avatar

What would cause the parts of the world to stop supporting the populations, food production and energy and GDP have been steadily rising everywhere (except maybe North Korea) so I do see what would cause it, and there is no dial for easing back or increasing the population, it’s a natural response to society.

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