Global Carbon Budget

Global carbon dioxide emissions

According to the latest Global Carbon Budget (2025), the total global fossil fuel carbon dioxide (CO₂) emissions (fossil fuels and land use change) in 2025 are projected to increase by 1.1 per cent, hitting a record 42.2 billion tonnes.

Fossil fuel 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 2025 compared to 2024. Coal accounted for 41 per cent of global CO₂ emissions (up 0.8 per cent), oil accounted for 32 per cent (up 1 per cent), and natural gas accounted for 21 per cent (up 1.3 per cent).

While fossil fuel CO₂ emissions continue to increase, the average trend in CO₂ emissions from land-use changes, such as deforestation, have declined. This means that the trend in total emissions from both fossil fuels and land use change has grown only by 0.3 per cent per year over the last decade.

Along with this slower growth trend, total CO₂ emissions are projected to decrease to 42.2 billion tonnes in 2025, down from 42.4 billion tonnes in 2024, with climate impacts on land and ocean carbon sinks contributing to the rise in atmospheric CO₂ concentration. These emissions have led to a further increase in the CO₂ concentrations in the atmosphere, with fossil fuel emissions responsible for the largest fraction of that growth. 

Changes in global fossil CO₂ emissions

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

China’s emissions (32 per cent of the global total) are projected to increase by 0.4 per cent over 2025 with uncertainties large enough to cover the possibility of no growth or slight decline. The low emission growth expected in 2025 is due to moderate growth in energy consumption combined with an extraordinary growth in renewable power generation.

The United States’ emissions (13 per cent of global) are projected to increase by 1.9 per cent, significantly above recent trends, due to greater heating requirements and an in increase in total demand for electricity.

India’s emissions (8 per cent of global) are projected to increase by 1.4 per cent, significantly below recent trends, due to reduced cooling requirements and strong growth in renewables.

European Union emissions (7 per cent of global) are projected to increase by 0.4 per cent, above recent trends but with uncertainties showing also the possibility of stable emissions. Coal use declined and solar power expanded, however, there was an increase in electricity generation from natural gas.

Emissions in the rest of the world (38 per cent of the global total) are projected to increase by 1.1 per cent.

Over the past decade, 35 countries have had declining CO₂ emissions, while growing their economies. This is twice the number of countries during the previous decade (2005-2014). These 35 countries account for 27 per cent of global fossil CO₂ emissions, and include countries as diverse as Australia, Bulgaria Denmark, Estonia, Germany, Israel, Jordan, New Zealand, Portugal, Romania Slovenia, Taiwan, Thailand, United Kingdom, and the United States.

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 2.2 billion tonnes of CO₂ per year. This offset around half of the emissions from permanent deforestation.

At current emission levels, the remaining carbon budget for a 50 per cent chance to limit warming to 1.5°C will likely be exceeded in four years.

Global carbon dioxide emissions

According to the latest Global Carbon Budget (2025), the total global fossil fuel carbon dioxide (CO₂) emissions (fossil fuels and land use change) in 2025 are projected to increase by 1.1 per cent, hitting a record 42.2 billion tonnes.

Fossil fuel 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 2025 compared to 2024. Coal accounted for 41 per cent of global CO₂ emissions (up 0.8 per cent), oil accounted for 32 per cent (up 1 per cent), and natural gas accounted for 21 per cent (up 1.3 per cent).

While fossil fuel CO₂ emissions continue to increase, the average trend in CO₂ emissions from land-use changes, such as deforestation, have declined. This means that the trend in total emissions from both fossil fuels and land use change has grown only by 0.3 per cent per year over the last decade.

Along with this slower growth trend, total CO₂ emissions are projected to decrease to 42.2 billion tonnes in 2025, down from 42.4 billion tonnes in 2024, with climate impacts on land and ocean carbon sinks contributing to the rise in atmospheric CO₂ concentration. These emissions have led to a further increase in the CO₂ concentrations in the atmosphere, with fossil fuel emissions responsible for the largest fraction of that growth. 

Changes in global fossil CO₂ emissions

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

China’s emissions (32 per cent of the global total) are projected to increase by 0.4 per cent over 2025 with uncertainties large enough to cover the possibility of no growth or slight decline. The low emission growth expected in 2025 is due to moderate growth in energy consumption combined with an extraordinary growth in renewable power generation.

The United States’ emissions (13 per cent of global) are projected to increase by 1.9 per cent, significantly above recent trends, due to greater heating requirements and an in increase in total demand for electricity.

India’s emissions (8 per cent of global) are projected to increase by 1.4 per cent, significantly below recent trends, due to reduced cooling requirements and strong growth in renewables.

European Union emissions (7 per cent of global) are projected to increase by 0.4 per cent, above recent trends but with uncertainties showing also the possibility of stable emissions. Coal use declined and solar power expanded, however, there was an increase in electricity generation from natural gas.

Emissions in the rest of the world (38 per cent of the global total) are projected to increase by 1.1 per cent.

Over the past decade, 35 countries have had declining CO₂ emissions, while growing their economies. This is twice the number of countries during the previous decade (2005-2014). These 35 countries account for 27 per cent of global fossil CO₂ emissions, and include countries as diverse as Australia, Bulgaria Denmark, Estonia, Germany, Israel, Jordan, New Zealand, Portugal, Romania Slovenia, Taiwan, Thailand, United Kingdom, and the United States.

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 2.2 billion tonnes of CO₂ per year. This offset around half of the emissions from permanent deforestation.

At current emission levels, the remaining carbon budget for a 50 per cent chance to limit warming to 1.5°C will likely be exceeded in four years.