2021 IPCC report: the global carbon budget will run out in 9 years

The IPCC AR6 Report of 2021 indicates that the remaining carbon budget to remain within 1.5°C of global warming is 400 billion tonnes CO2.

For an average country, its share of the global carbon budget will run out in 9 years.

For a high polluting county such as the UK, its share of the carbon budget will run out in 3 years.

Greenhouse gas emissions need to be rapidly reduced by phasing out fossil fuels.

IPCC report of 2021

The AR6 WG1 report [1] was released by the Intergovernmental Panel on Climate Change (IPCC) in August 2021. (The IPCC is the United Nations body for assessing the science related to climate change.)

The report includes figures for the carbon budget for 1.5°C, which is how much more CO2 can be released into the atmosphere globally without pushing global warming above 1.5°C. The calculations are based on how much CO2 has been emitted by mankind to date, and what effect this has had on global temperatures.

Carbon budget calculations had been adjusted slightly since the previous IPCC report of 2018, according to the further information available.

The residual global carbon budget to remain within 1.5°C global warming with 66% probability is given as 400 billion tonnes CO2 from the start of 2020.

With the world population reaching 8 billion people within the next few years, this is 50 tonnes per person.

Global CO2 emissions are about 36 billion tonnes per year (document 94), so the 400 billion tonnes will last just 11 years if no reductions are made, i.e. the global carbon budget runs out at the end of 2030.

For a high polluting country such as the UK, with CO2 emissions of 10 tonnes per person per year, the carbon budget will run out by the end of 2024, i.e. in 3 years - see document 33.

Most people are either unaware or in denial about the severity and urgency of the climate emergency.

Some key excerpts are:

IPCC report of 2018

The SR15 report [4][5][6] was released by the IPCC in 2018.

Some key excerpts are:

Little action has been taken by governments in response to this report.


[1]IPCC (Aug 2021) AR6 Climate Change 2021: The Physical Science Basis https://www.ipcc.ch/report/ar6/wg1/
[2]Secretary-General's statement on the IPCC Working Group 1 Report on the Physical Science Basis of the Sixth Assessment (Aug 2021) https://www.un.org/sg/en/content/secretary-generals-statement-the-ipcc-working-group-1-report-the-physical-science-basis-of-the-sixth-assessment
[3]Abdalah Mokssit (Secretary of the IPCC) (Aug 2021) IPCC press conference https://un-spbf.org/event/ipcc-press-release-climate-action-cannot-wait/
[4]IPCC (Oct 2018) SR15 report press release https://www.ipcc.ch/site/assets/uploads/2018/11/pr_181008_P48_spm_en.pdf
[5]IPCC (Oct 2018) SR15 report headline statements https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Headline-statements.pdf
[6]IPCC (Oct 2018) SR15 Summary for policymakers https://www.ipcc.ch/site/assets/uploads/sites/2/2018/07/SR15_SPM_version_stand_alone_LR.pdf

First published: Feb 2019
Last updated: 8 Apr 2022