Global CO2 emissions reach record high in 2025

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Global fossil CO₂ emissions will further increase in 2025. Some 38.1 billion metric tons of CO₂ will be emitted, which represents a new record and surpasses 2024 emissions by 1.1%. This is the conclusion of the latest report by the Global Carbon Project (GCP), an association of international scientists. Researchers from LMU Munich and the Alfred Wegener Institute (AWI) / University of Bremen were leading contributors to the study.

The report reveals that although global CO₂ emissions over the past decade (2015-2024) increased more slowly (average of 0.3% rise per year) than over the previous decade (average of 1.9% rise per year), climate action efforts remain well shy of what is needed to bring global emissions down to net zero in the long term.

Decarbonization is making progress

The authors welcomed the substantial slowdown in the increase of fossil CO₂ emissions in China and India, which is attributed among other factors to a strong expansion of renewables in these countries. Globally, 35 countries – including the United States and the countries of the European Union – have managed to reduce their fossil CO₂ emissions over the past decade, while their economies grew – twice as many countries as in the previous decade. The decarbonization of energy systems is advancing in many countries. However, this is not sufficient to balance out the increase in global energy demand.

Already, the remaining carbon budget to limit global warming to 1.5°C with a probability of 50 percent has been almost exhausted: If the level of emissions projected for 2025 continues, we have only four years left to keep to this target. To limit warming to 1.7°C or 2°C with a 50 percent probability, the carbon budget would, as things stand, last for another 12 or 25 years respectively.

Emissions from fossil fuels

The GCP projections show that emissions from all fossil sources – coal, oil, and gas – will increase globally in 2025 (on average, coal by 0.8%, oil by 1%, and gas by 1.3%). In Europe, although emissions from burning coal are decreasing, emissions from oil and gas are going up.

In the transport sector, emissions from international aviation are projected to increase by 6.8%, while emissions from shipping will remain stable.

Fall in land use emissions

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Unlike their predictions for fossil emissions, the researchers project a fall in land use emissions. According to the provisional data, overall emissions from land use changes in 2025 will amount to 4.1 billion metric tons of CO₂, slightly down on the figure for 2024. “The decrease in emissions from land use shows how successful environmental policy can be,” says Julia Pongratz, Professor of Physical Geography and Land Use Systems, who led the work to estimate land use emissions at LMU together with Dr. Clemens Schwingshackl. “Deforestation rates in the Amazon region have fallen, and this season they are at their lowest level since 2014.”

Ocean and land sinks

Over the past ten years, the world’s oceans have absorbed 29% of total CO₂ emissions. “This makes oceans the largest natural sink for anthropogenic CO₂ emissions,” says Professor Judith Hauck, environmental researcher at AWI, who coordinated the estimation of the ocean sink. Since 2016, however, the ocean sink has remained largely static, which is primarily attributable to climatic fluctuations weakening the previous upward trend. In addition, it was influenced by the heat wave in the northern hemisphere’s oceans in 2023-2024.

The absorption of CO₂ from the atmosphere by the continents’ ecosystems – the so-called terrestrial sink – suffered a sharp decline in 2024 due to El Niño. For 2025, the data indicates a recovery to the level from before this climate phenomenon. “The devastating fires of 2024 have shown how sensitive ecosystems can be if we don’t limit global warming,” emphasizes Schwingshackl. “Climate protection is in fact ecosystem protection too.”

About the Global Carbon Project

The GCP is an international research project by the Future Earth initiative for global sustainability. An international team of more than 130 climate researchers compiles the report, which is updated annually – this year for the twentieth time. The new edition will be presented on 13 November 2025 as part of the 30th UN Climate Change Conference in Belém. An accompanying publication, which sets out methodological improvements for the Global Carbon Project report, will be appearing in the journal Nature.

Contributors from the German-speaking world come from the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (Bremerhaven), ETH Zurich, Helmholtz-Zentrum Hereon (Geesthacht), the International Institute for Applied Systems Analysis (IIASA), Karlsruhe Institute of Technology, the Leibniz Institute for Baltic Sea Research Warnemünde (IOW), LMU Munich, the Max Planck Institute for Meteorology (Hamburg), the Max Planck Institute for Biogeochemistry (Jena), the Potsdam Institute for Climate Impact Research, as well as the Universities of Bern, Bremen, and Hamburg. These researchers contributed ocean observations, model simulations of ocean, land, and atmosphere, and various analyses to the report.

Friedlingstein et al.: Global Carbon Budget 2025. Earth System Science Data 2025

Friedlingstein et al.: Emerging climate impact on carbon sinks in a consolidated carbon budget. Nature 2025