[reducesuffering]

The per-capita point is brought up a lot, but there's a serious flaw that I don't think is very often addressed. If a country has runaway population growth, they can keep their per-capita emissions low, while in total growing their emissions catastrophically as a country. If the rest of the world is able to get their emissions per-capita under control, it doesn't matter if this overpopulating country also has low emissions per-capita if they continue to exponentially increase their emissions, while the rest of world stalls their total emissions. Because of this, I think it's important to keep in mind that both total and per-capita emissions are important.

[brippalcharrid]

Isn't the definition of a country quite arbitrary, though, in this context? If we disapprove of the population of a certain country growing beyond a particular size, would we any happier if that country were to split in two, and for their citizens to then double in number? Or for it to split into four countries, and for its citizens to increase their emissions and living standards to the level of more developed nations. I understand the temptation to pick the world as it is now as a standard by which to measure what countries ought to do in the future, but it's terribly easy for a person to do that if they don't then have to live in a country which hasn't yet reached the living standards of post-industrial society.

[JoeAltmaier]

Which country is that? I'm not sure I know of a country with runaway population growth.

[brippalcharrid]

Nigeria is the one stand-out country that has stubbornly refused to become [much] less fertile as it developed. It's quite an outlier (was ~6.4 in 1960, up to ~6.8 in 1980, now ~5.4).

LOL at the y-axis on that graph ;)

https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...

[reducesuffering]

The runaway example is more of a thought experiment to illustrate why emissions per-capita, in isolation, is flawed and can still lead to devastating climate change effects. In reality, there probably won’t be countries with unlimited population growth, but India, Nigeria, and other African countries will be adding several billion people to the planet in the future decades while most of the rest of the world will be even or decline. As climate change effects become increasingly real over the next couple decades, I don’t see the rest of world being amenable to decreased standards of living while other countries add people to developed standards of living. It’s likely countries will try to coalesce around existing populations being assigned a per-capita total emissions limit for their current population. Where a country’s additional population will come at the expense of the existing country’s population’s ability to emit.

[JoeAltmaier]

Again, I'm not sure that's true. India and almost all African countries are approaching replacement population change asymptotically.