Global carbon budget

Global carbon dioxide emissions

According to the latest global carbon budget (2023), the total global fossil carbon dioxide (CO₂) emissions in 2023 are projected to increase by 1.1 per cent, hitting a record 36.8 billion tonnes.

Fossil CO₂ includes emissions from the combustion and use of fossil fuels (coal, oil and gas) and cement production. These emissions account for about 90 per cent of all CO₂ emissions from human activities.

Emissions from all fossil sources increased in 2023 compared to 2022. Coal accounted for 41 per cent of global CO₂ emissions (up 1.1 per cent), oil accounted for 32 per cent (up 1.5 per cent), natural gas accounted for 21 per cent  (up 0.5 per cent) and cement accounted for 4 per cent (up 0.08 per cent).

While fossil CO₂ emissions continue to increase, net emissions from land-use change, such as deforestation (CO₂ source), minus CO₂ removals, such as reforestation (CO₂ sink), fell. Net emissions from land-use change were 4.1 billion tonnes of CO₂ in 2023.

Terrestrial vegetation and ocean absorb about half of all CO₂ emissions. This fraction has remained stable for six decades.

Changes in global fossil CO₂ emissions

Although global emissions have increased, the picture for individual countries varies.

China’s emissions (31 per cent of the global total) increased by 4 per cent with growth in all fossil fuel sources. The highest relative growth was from oil emissions. This was in part due to the transport sector’s recovery after COVID-19 pandemic shutdowns.

The United States’ emissions (14 per cent of global) were down by 3 per cent. The rapid retirement of coal-fired power plants drove most of this decline. US coal emissions are the lowest since 1903.

India’s emissions (8 per cent of global) increased by 8.2 per cent. Emissions for all fossil fuels grew by 5 per cent or more, with coal the highest at 9.5 per cent. India is now the world’s third-largest fossil CO₂ emitter.

European Union emissions (7 per cent of global) are down by 7.4 per cent. This decline was due to both high renewable energy penetration and the impacts on energy supply of the war in Ukraine.

During the decade of 2013-2022, 26 countries had declining fossil CO₂ emission trends while their economies continued to grow. The list includes Brazil, France, Germany, Italy, Japan, Portugal, Romania, South African, United Kingdom and USA.

Besides the natural CO₂ sinks, humans are also removing CO₂ from the atmosphere through deliberate activities. We estimate permanent reforestation and afforestation over the past decade have removed about 1.9 billion tonnes of CO₂ per year. This is equivalent to 5 per cent of fossil fuel emissions per year.

At current emission levels, the remaining carbon budget for a one-in-two chance to limit warming to 1.5°C will likely be exceeded in seven years, and in 15 years for 1.7°C.