Allocation of the residual global CO2 budget between countries

How should the residual CO2 budget be divided between countries?

In order to be confident of keeping global warming to less than 1.5°C, further global CO2 emissions must be kept below a total of 400 billion tonnes since 2020 - see document 54. This 400 billion tonnes is known as the residual carbon CO2 budget (or carbon budget); it is currently dwindling at a rate of 34 billion tonnes CO2 per year.

A vital question on which there is little discussion is what principle should be used to divide this residual CO2 budget between countries.

Possible ways of dividing the residual CO2 budget

Considerations in dividing the residual CO2 budget


The only justifiable principle for allocation of the residual CO2 budget is that the developed countries take no more than their fair per-capita share.

Who is advocating a fair (per capita) allocation of the residual carbon budget?

Who is advocating that developed countries take much more than a per capita allocation of the residual CO2 budget?


[1]The Paris Agreement (2015)
[2]Tyndall Centre The Tyndall carbon budget tool (2019)
[3]"Zero carbon sooner" carbon budget report from CUSP
[4]UK Government Net Zero Strategy: Build Back Greener (Oct 2021)

First published: 25 Oct 2021
Last updated: 11 Sep 2022