In 2015, almost every country on Earth signed up to the historic Paris Agreement on climate change. It required every country to limit its carbon emissions so that the planet was not warmed by more than 1.5 to 2°C by 2050. The amount of carbon dioxide emissions that each country was limited to is known as the global “carbon budget”. It varies from country to country.1
Put simply, a carbon budget is the total amount of CO2 emissions allowed to stay within a global warming range over a period of time. Scientists created this measure to make it easier to understand the emissions that countries and companies should limit themselves to. This is to prevent the world from heating up by 2°C, for example.2
Why every country must be responsible for the global carbon budget
The Paris Agreement made it incumbent on every country to play a part in limiting carbon dioxide emissions. It takes into account that each country has a different size, emissions and historic contribution to CO2 emissions. Therefore, every country has a different carbon budget.
Nevertheless, every country must play its part in sticking to a carbon budget. Otherwise, the system breaks down. These carbon budgets can be flexible. But, we can only deal with climate change through international cooperation.3

Photo by Martin Damboldt from Pexels
The UK is one of the few to consider including its shipping emissions in its carbon budget
The UK was the first country worldwide to create a legally binding commitment to a carbon budget. It introduced the concept in the 2008 Climate Change Act to reduce CO2 emissions by at least 80 per cent below 1990 levels by 2050.
In 2021, the UK government went a step further with a legally binding aim to slash its carbon dioxide emissions by 78 per cent by 2035 in the UK’s sixth carbon budget. Also, for the first time, the UK incorporated its share of international aviation and shipping emissions. The UK is the only government in the world to do this.4
The carbon budget and the Paris Agreement
The Paris Agreement had one big impact on global carbon budgets. It increased emphasis on limiting global warming to 1.5°C instead of accepting a rise of 2°C by 2050. In this sense, the Paris Agreement was highly influential and important. It forced countries to grapple with the urgency of climate change and make big changes to reduce carbon emissions.5
Sources
- Hausfather, Z. (2018). Analysis: How much “carbon budget” is left to limit global warming to 1.5C? | Carbon Brief. [online] Carbon Brief. Available at: https://www.carbonbrief.org/analysis-how-much-carbon-budget-is-left-to-limit-global-warming-to-1-5c.
- Carbon Tracker Initiative. (2018). Carbon Budgets Explained. [online] Available at: https://carbontracker.org/carbon-budgets-explained/.
- RealClimate. (2019). How much CO2 your country can still emit, in three simple steps. [online] Available at: https://www.realclimate.org/index.php/archives/2019/08/how-much-co2-your-country-can-still-emit-in-three-simple-steps/ [Accessed 18 May 2021].
- GOV.UK. (2021). UK enshrines new target in law to slash emissions by 78% by 2035. [online] Available at: https://www.gov.uk/government/news/uk-enshrines-new-target-in-law-to-slash-emissions-by-78-by-2035.
- Carbon Tracker Initiative. (2020). Carbon budgets: Where are we now? [online] Available at: https://carbontracker.org/carbon-budgets-where-are-we-now/.