Annual CO2 emissions from land-use change by major emitting countries and the rest of world over 1959-2024. Country-level land-use change emissions are not yet available for 2025. Data from the Global Carbon Project. Chart by Carbon Brief.
Historical land-use emissions have been revised upward in the 2025 GCB report compared to prior estimates. This reflects a combination of two factors:
Global emissions of fossil CO2 – including coal, oil, gas and cement – increased by around 1.1 per cent in 2025, relative to 2024, with an uncertainty range of 0.2-2.2 per cent. This represents a new record high and surpasses the prior record set in 2024.
The figure below shows global CO2 emissions from fossil fuels, divided into emissions from major emitting countries including China (dark blue shading), the US (mid blue), the EU (light blue), India (light blue) and the remainder of the world (grey).
Annual fossil CO2 emissions by major countries and the rest of the world over 1959-2025. This data excludes the cement carbonation sink as national-level values are not available, meaning that the sum of values reported here are slightly higher than the global average numbers. Data from the Global Carbon Project. Chart by Carbon Brief.
China represents 32 per cent of global CO2 emissions today. Its 2025 emissions are projected to increase by a relatively small 0.4 per cent (with an uncertainty range of -0.9 per cent to 2 per cent), driven by a small rise in emissions from coal (0.3 per cent), a modest rise in gas (1.3 per cent) and a larger rise in oil (2.1 per cent).
Given the uncertainty range, a decrease in Chinese emissions is also a possibility, but this will not be confirmed until the full 2025 data is available.
Similarly, recent analysis for Carbon Brief found that China’s emissions were “finely balanced between a small fall or rise” in 2025. However, it said that a drop in the full-year total became more likely after a 3 per cent decline in September. (The Global Carbon Project estimates are based on data covering January through to August, which point towards a small rise in 2025.)
Whether China’s emissions see small rise or fall in 2025, the outcome will be due to moderate growth in energy consumption combined with an extraordinary growth in renewable power generation. This would represent the second year in a row where Chinese emissions growth was well below the average rate over the past decade.
The US represents 13 per cent of global emissions and emissions in 2025 are projected to increase by 1.9 per cent (-0.2 to +4.1 per cent) compared with 2024. This marks a reversal from recent trends in declining CO2 emissions.
The projected growth of emissions in the US is likely driven by a combination of three factors: a colder start to the year after a mild 2024, which led to greater heating requirements, higher gas prices, which led to more coal being used in power generation, as well as an increase in total demand for electricity.
US emissions from coal are expected to increase by a substantial 7.5 per cent in 2025, emissions from both oil and gas by a more modest 1.1 per cent and emissions from cement to fall by -8.0 per cent.
While policies enacted by the current US administration may increase CO2 emissions going forward, their impact on national emissions levels in 2025 were likely relatively modest compared to other factors.
India represents 8 per cent of global emissions. In 2025, its emissions are projected to increase by 1.4 per cent (-0.3 per cent to +3.1 per cent) on 2024 levels, significantly below recent trends.
An early monsoon with the highest-ever May rainfall substantially reduced cooling requirements in May and June, the hottest months of the year. Strong growth or renewables – particularly solar – has also helped limit the growth of Indian emissions.
Indian emissions from coal are expected to grow 1.7 per cent, with oil growing 0.1 per cent, gas shrinking by -6.4 per cent and cement growing by 9.9 per cent.
The EU represents 6 per cent of global emissions. Its emissions are projected to increase by 0.4 per cent in 2025, with an uncertainty range of -2.1 to +2.8 per cent. This represents a divergence from a past decline in emissions (albeit with large uncertainties).
EU emissions from coal are expected to decline by -0.3 per cent, whereas emissions from oil and gas are projected to increase by 0.6 per cent and 0.9 per cent, respectively. Cement emissions are expected to fall by -4.1 per cent.
The increase in EU emissions is in part from weather-related low hydropower and wind generation which – despite increases in solar – have led to an increase in electricity generation from gas. In addition, a relatively cold February led to increased use of natural gas for space heating.
International aviation and shipping (included in the “rest of world” in the chart above) are responsible for 3 per cent of global emissions. They are projected to increase by 6.8 per cent for aviation, but remain flat for international shipping. This year will be the first time that aviation emissions have exceeded pre-Covid levels.
The rest of the world (excluding aviation) represents 38 per cent of global emissions. Emissions are expected to grow by 1.1 per cent in 2025 (ranging from -1.1 per cent to +3.3 per cent), with increases in emissions from coal (1 per cent), oil (0.5 per cent), gas (1.8 per cent) and cement (2.4 per cent).
The total emissions for each year over 2022-25, as well as the countries and regions that were responsible for the changes in absolute emissions, are shown in the figure below.
Annual emissions for 2022, 2023, 2024 and estimates for 2025 are shown by the black bars. The smaller bars show the change in emissions between each set of years, broken down by country or region – the US (dark blue), EU (mid blue), China (light blue), India (pale blue) and the rest of the world (grey). Negative values show reductions in emissions, while positive values reflect emission increases.
Annual global CO2 emissions from fossil fuels (navy blue bars) and drivers of changes between years by country (smaller bars), excluding the cement carbonation sink as national-level values are not available. Negative values indicate reductions in emissions. Note that the y-axis does not start at zero. Data from the Global Carbon Project. Chart by Carbon Brief.
The US represented a large part of the rise in global fossil-fuel emissions in 2025. US emissions increases over 2024-25 contributed about 40 per cent of the total global increase – more than the EU, China and India contributions combined.
The Global Carbon Project notes that emissions have declined over the past decade (2015-24) in 35 nations, which collectively account for 27 per cent of global emissions. This is up from 18 countries during the prior decade (2005-14).
The decrease in emissions in those countries comes despite continued domestic economic growth and represents a long-term “decoupling” of CO2 emissions and the economy.
The carbon intensity of energy has consistently decreased over the past decade in China, the US, the EU – and, to a lesser extent, globally.
However, peaking CO2 emissions requires that the rate of decarbonisation exceeds the growth in energy demand. This has happened in some regions, including the US and EU, but not yet globally.
Modest growth in emissions from coal, oil, gas and cement
Global fossil-fuel emissions primarily result from the combustion of coal, oil and gas.
In 2025, coal is responsible for more emissions than any other fossil fuel, representing approximately 42 per cent of global fossil-fuel CO2 emissions. Oil is the second largest contributor at 33 per cent of fossil CO2, while gas comes in at 21 per cent.
The production of cement is responsible for around 3.8 per cent of global emissions, but this is reduced to 1.9 per cent once the carbonation sink – the drawdown of atmospheric CO2 by concrete – is taken into account.
These percentages reflect both the amount of each fossil fuel consumed globally, but also differences in CO2 intensities. Coal results in the most CO2 emitted per unit of heat or energy produced, followed by oil and gas.
The figure below shows global CO2 emissions from different fuels over time, covering coal (dark blue), oil (mid blue) and gas (light blue), as well as cement production (pale blue) and other sources (grey).
While coal emissions increased rapidly in the mid-2000s, they have largely flattened since 2013. However, coal use increased significantly in 2021 and then more modestly in the subsequent four years.
Annual CO2 emissions by fossil fuel over 1959-2025. Data from the Global Carbon Project. Chart by Carbon Brief.
Global emissions from coal increased by 0.8 per cent in 2025 compared to 2024, while oil emissions increased 1.0 per cent and gas emissions increased by 1.3 per cent.
Despite setting a new record this year, global coal use is only 6 per cent above 2013 levels – a full 13 years ago. By contrast, during the 2000s, global coal use grew at a rate of around 4 per cent every single year.
The figure below shows the total emissions for each year over 2022-25 (black bars), as well as the absolute change in emissions for each fuel between years.
Annual global CO2 emissions from fossil fuels (black bars) and drivers of changes between years by fuel. Negative values indicate reductions in emissions. Note that the y-axis does not start at zero. Data from the Global Carbon Project. Chart by Carbon Brief.
Global oil emissions were suppressed for a few years after the 2020, but rebounded to pre-pandemic levels as of 2024 and have continued to grow in 2025.
This reflects that, despite falling sales of internal combustion engine vehicles, not enough electric vehicles (EVs) have yet been sold to result in peak oil demand.
The global carbon budget
Every year, the Global Carbon Project provides an estimate of the overall “global carbon budget”. This is based on estimates of the release of CO2 through human activity and its uptake by the oceans and land, with the remainder adding to atmospheric concentrations of the gas.
(This differs from the commonly used term “remaining carbon budget”, which refers to the amount of CO2 that can be released while keeping warming below global limits of 1.5 or 2°C.)
The most recent budget, including estimated values for 2025, is shown in the figure below.
Values above zero represent sources of CO2 – from fossil fuels and industry (dark blue shading) and land use (mid blue) – while values below zero represent carbon sinks that remove CO2 from the atmosphere. Any CO2 emissions that are not absorbed by the oceans (light grey) or land vegetation (mid grey) accumulate in the atmosphere (dark grey). In addition, a dashed black line is shown to represent the expected sum of sinks based on estimated emissions.
Annual global carbon budget of sources and sinks over 1959-2025. Fossil CO2 emissions include the cement carbonation sink. Note that the budget does not fully balance every year due to remaining uncertainties, particularly in sinks; the imbalance can be seen by the difference between the sum of the sinks and the sum of the sources (dashed black line). Data from the Global Carbon Project. Chart by Carbon Brief.
Over the past decade (2015-24), the world’s oceans have taken up approximately 29 per cent of total human-caused emissions, or around 11.8GtCO2 per year.
The ocean CO2 sink has been relatively flat since 2014 after growing rapidly over the prior decades, reflecting the flattening of global emissions during that period.
This estimate for carbon sinks has been revised up from 26 per cent in prior versions of the GCB, reflecting a major update to carbon budgets driven by new data and modelling of carbon sink behavior.
The land sink takes up around 21 per cent of global emissions, or 8.7GtCO2 per year on average over the past decade – discussed in more detail in the section below. This is down from 29 per cent in prior budgets.
The atmosphere continues to accumulate the bulk of human-caused CO2 emissions, with about 49 per cent going into the atmosphere on average over the past decade – a rate of 20.4GtCO2 per year.
The growth rate of atmospheric CO2 in 2025 is expected to be around 2.3ppm, which is a bit below the decadal average rate of 2.6ppm over the past decade (2015-24). This is well below the record-setting rise of 3.7ppm in 2024, which was primarily driven by the effect of the 2023-24 El Niño conditions weakening the land sink.
Atmospheric CO2 concentrations are set to reach an annual average of 425.7ppm in 2025, representing an increase of 52 per cent above pre-industrial levels of 280ppm.
There remains an unusual imbalance in the carbon budget in 2024, where the sum of the sinks is notably larger than estimated emissions. This can be seen in the figure above, where the dashed line is below the shaded area.
Budget imbalances are not unprecedented – there are large uncertainties in both emissions data and sink estimates. But the rise in the amount of CO2 accumulating in the atmosphere in 2024 is larger than would be expected based on emissions.
There are a number of potential explanations for this 2024 imbalance. The land cover data for 2024 is not yet complete and it is possible that some fire emissions data might be missing from the record. This might result in either higher land-use emissions or lower land sinks than currently estimated.
Alternatively, it could be due to the CO2 growth rate – captured by surface stations managed by the US National Atmospheric and Oceanic Administration (NOAA) – being slightly high. CO2 records for 2024 from these stations are higher than those obtained from satellite-based sensors, though it remains unclear which provides the most accurate measurement.
A declining, but not collapsing, land sink
After an usually weak land carbon sink in 2023, there were a number of media articles about its potential collapse.
For example, in October 2024, the Guardian wrote that “the sudden collapse of carbon sinks was not factored into climate models – and could rapidly accelerate global heating”.
The truth is a bit more complicated. While the impending collapse of the land carbon sink has been greatly exaggerated, there is growing evidence of a long-term weakening of both the land and ocean carbon sinks due to human activity.
And while the land sink has recovered to its pre-El Niño strength in 2025, aided by relatively low global fire CO2 emissions, it will continue to gradually weaken as global temperatures rise. This is not unexpected – scientists have long foreseen a weaker carbon sink in a warmer world.
A weaker land sink will contribute to higher global temperatures in the future as more CO2 emissions from burning fossil fuels and land use change will accumulate in the atmosphere.
The figure below shows the percentage of human emissions absorbed by the land sink in every year since 1959, with a recovery upwards in 2025 after two relatively low years.
Percentage of global CO2 emissions (land use and fossil) taken up by the land sink each year. Data from the Global Carbon Project. Chart by Carbon Brief.
In a study published in Nature alongside the release of the 2025 Global Carbon Budget, the same team of researchers provide a detailed estimate of exactly how the land and ocean sinks have changed as a result of human activity.
The research finds that the land and ocean sinks are 25 per cent smaller and 7 per cent smaller, respectively, than they would have been without the effects of climate change over 2015-24.
This amounts to a nearly 20 per cent reduction in the efficacy of current global carbon sinks – that is, both the land and ocean – and a 15 per cent reduction compared to how large they would be without the effects of climate change.
The figure below, from the new paper, shows the impact of climate change on the ocean sink (blue), the land sink (green) and atmospheric CO2 concentrations (grey) since 1960.
Impact of climate change on the land sink (panel a), the ocean sink (panel b) and their cumulative effect on atmospheric CO2 concentrations (panel c). Source: Friedlingstein et al. (2025).
The weakening of carbon sinks due to human activity has led to an increase of atmospheric CO2 of more than 8ppm since 1960. The combined effects of climate change and deforestation have turned tropical forests in Southeast Asia and in large parts of South America from CO2 sinks to sources.
And these sinks will likely continue to weaken as long as atmospheric CO2 concentrations continue to rise and the world continues to warm. There are a wide range of estimates of carbon cycle feedbacks among climate models, but a large carbon cycle feedback could result in a few tenths of a degree of future warming.
This story was published with permission from Carbon Brief.
