The UK Net Zero strategy would take three times the UK's share of the global CO2 budget

The UK Government published its Net Zero 2050 climate strategy in October 2021. This web page is an assessment of whether the strategy complies with the Paris Agreement and the need to limit global warming to 1.5°C.

The UK's CO2 emissions are currently about 10 tonnes per person per year. The UK Government plans to reduce this steadily to zero over the 30 years to 2050. This gives total CO2 emissions of 150 tonnes per person.

But the residual global carbon budget to keep global warming to 1.5° is just 50 tonnes CO2 per person.

So the UK's Net Zero 2050 strategy would take three times the UK's share of the residual global CO2 budget, and so is not consistent with the Paris Agreement.

At such a crucial time, it is vital that the UK Government takes an honest and responsible approach to the climate emergency, and that any departure from this is not tolerated.

The following 10 steps allow readers to look at the figures from the original sources and perform or verify the calculations themselves.

A. The current CO2 emissions from the UK population
1. The UK's total greenhouse gas emissions can be obtained from the report from the Department of Business, Energy and Industrial Strategy at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/957887/2019_Final_greenhouse_gas_emissions_statistical_release.pdf.
The report's Figure 1 (p4), shown on the right, shows that the "Consumption-based emissions" (which includes net imports but excludes aviation and shipping) are 790 million tonnes CO2 equivalent per year.

2. Only 80% of this 790 million tonnes is CO2; the rest is other greenhouse gases (as explained in the report). So the UK emits 790 x 80%, i.e. 630 million tonnes CO2 per year.

3. The UK population can be found at https://www.unfpa.org/data/world-population-dashboard - it is 68 million.

4. Dividing the total UK CO2 emissions (630 million tonnes) by the UK population (68 million) gives the per person CO2 - it is 9.3 tonnes CO2 per person per year.

5. An amount for UK aviation needs to be added. This is an uncertain figures due to uncertainty in the ratio of UK to foreign nationals travelling throught UK airports, and over radiative forcing, but UK aviation uses at least 15 million tonnes oil per year (https://www.ons.gov.uk/file?uri=/economy/environmentalaccounts/datasets/ukenvironmentalaccountsfuelusebytypeandindustry/current/fuelusebytypeandindustry.xls), which would give 38 million tonnes CO2 for the UK, i.e. 0.6 tonnes CO2 per person. Adding this to 9.3 tonnes and rounding gives UK emissions of 10 tonnnes CO2 per person per year.


B. The total UK emissions during the period covered by the plan (to 2050)
6. The planned emission cuts are set out in the UK Net Zero 2050 strategy document at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1033990/net-zero-strategy-beis.pdf.
An edited version of Figure 12 from p76 is shown on the right. The planned decline in emissions is close to a straight line from the current figure at 2020 to zero at 2050.

7. Since the current figure is 10 tonnes per person per year, and there is a steady decline to zero, the average over the 30 year period is 5 tonnes per person per year, and the total over the 30 year period is 30 x 5 tonnes i.e. 150 tonnes CO2 per person.


C. The residual global CO2 budget
8. The AR6 WG1 report was released by the Intergovernmental Panel on Climate Change (IPCC) in August 2021 at https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM_final.pdf. How much more CO2 humanity can release into the atmosphere is given in Table SPM.2 on page 29. This gives 400 billion tonnes CO2 as the amount that would limit global warming to 1.5°C with 67% confidence.

9. Dividing the total carbon budget of 400 billion tonnes CO2 by the world's population of 8 billion (https://www.unfpa.org/data/world-population-dashboard) gives the per person carbon budget of 50 tonnes CO2 per person. This is a lifetime limit.

D. Comparing the UK's planned total CO2 emissions with the global fair share
10. Comparing the UK's planned 150 tonnes CO2 per person with the global budget of 50 tonnes CO2 per person, the UK's timescale of cuts would take three times the global average.

What does the UK Net Zero 2050 strategy say about compliance with the global CO2 budget?

It says nothing. It does not mention it. The document is 368 pages long, it is a document about meeting the UK's commitments under the Paris Agreement, and yet the document does not even consider whether it succeeds in meeting this aim.

What are the consequences of the UK exceeding its share of the CO2 budget

The UK must choose between

Further reading and resources



First published 28 Jan 2022
Last updated: 4 Feb 2022