Relative numbers are what matters realistically when comparing countries. The comfort and buying power of 1.4 billion Chinese people counts as much as that of all of the citizens of the EU and USA together.

It is not in any way moral or acceptable to imagine that China or India should have lower total emissions than the EU or the USA, despite having many, many more citizens.

And this is not even discussing total historical emissions, which is what actually matters most for global warming, and where the first century of massive emissions was almost exclusively due to Europe and the USA.

Absolute numbers matter when considering the total CO2 budget for the Earth.

When considering how to divide that budget among the people of Earth absolute numbers for countries do not matter, because the atmosphere does not care about arbitrary lines humans draw on maps.

One easy way to see that per capita is the correct way to allocate the budget rather than per country is to consider what happens if countries split. Suppose we agree on a worldwide budget of 4 x 10^10 tons of CO2/year.

If we go by country each country's share is 2 x 10^8 tons/year. That would mean in a small country like Liechtenstein they could live a lifestyle that required 5000 tons/year/person.

Meanwhile, in the US we could only live a 0.6 ton/year/person lifestyle--about what Zimbabwe uses today. That's about 1/25th of the current US lifestyle.

That is not going to work. The US could hold a constitutional convention and dissolve with each of the current 50 states becoming an independent country, and at the same time make strong free trade and mutual defense treaties. They can call this the "American Union".

That raises the number of countries in the world, so each country now gets a smaller slice of that 4 x 10^10 tons/year global emission budget. Collectively the total emissions budget of the combined states in the American Union is around 8 x 10^10 tons/year. That allows the American Union to live a 24 ton/year/person lifestyle as a whole (which is 60% more than the current US lifestyle).

Of course China, which only gets a 0.16 ton/year/person lifestyle under the original country allocations could do the same thing. If they did the Chinese Union with the individual countries being what are now prefectures, that Chinese Union could have a 15 ton/year/person lifestyle (about the same as the current US CO2 emissions.

Each time a large country does this "split into a strong union of separate countries" thing the boost in how carbon intensive a lifestyle that union's residents can lives comes at the expense of a drop in what the rest of the world can have.

The limit of this is a world of thousands, or even millions, of micro-countries, each with about the same per capita CO2 allowance.

Hey, I personally produce less CO2 than the entire USA combined. I guess the USA better up its game!

No, but when talking about whether a country is emitting more than its "fair" share of GHG for any reasonable definition of "fair" per capita is what matters, unless someone can make a convincing argument that some people have some kind of natural or divine right to contribute more to GHG emissions than others.

More details are in this comment [1].

[1] https://news.ycombinator.com/item?id=42229636

Why didn't you include England's total historical contributions to GHG emissions and technologies in your comparison then?

The British Isles were not providing food, heating, cooling, electric light, raw materials etc for the population of the British Empire.

And if you want to count the population consuming industrial goods as the population that "causes" those emissions, then China looks even better, because they are producing goods consumed by literally billions of people.