Fossil CO2 emissions will reach a record high in 2025. If emissions remain at this level, the remaining carbon budget for staying within the 1.5°C limit is expected to be used up in four years.

Global fossil CO2 emissions will continue to rise in 2025, reaching 38.1 billion tons of CO2. This is a new record level, 1.1% above the 2024 figures. This is the conclusion of the latest report by the Global Carbon Project (GCP), a consortium of international scientists, in which researchers from Ludwig Maximilian University of Munich (LMU) and the Alfred Wegener Institute (AWI)/University of Bremen also played a leading role.

Previous climate protection efforts are far from sufficient

The report shows that global CO2 emissions in the last decade (2015-2024) have risen more slowly (by an average of 0.3% per year) than in the previous decade (an average of 1.9% per year), but that climate protection efforts to date are still far from sufficient to bring global emissions to net zero in the long term.

The remaining carbon budget to limit global warming to 1.5°C with a 50% probability is already practically exhausted: if the level of emissions forecast for 2025 continues, there are only four years left to meet this target. To limit warming to 1.7°C or 2°C with a 50 percent chance, the carbon budget would currently last for 12 or 25 years, respectively.

Decarbonization is progressing

The authors view as positive the fact that the increase in fossil CO2 emissions in China and India has slowed significantly, which is due, among other things, to the strong expansion of renewable energies in these countries. Globally, 35 countries – including the US and the countries of the European Union – have succeeded in reducing their fossil CO2 emissions over the last decade while their economies grew – twice as many countries as a decade ago. The decarbonization of energy systems is progressing in many countries. However, this is not enough to offset the increase in global energy demand.

Emissions from fossil fuels

GCP projections show that global emissions from all fossil fuel sources – coal, oil, and gas – will increase in 2025 (on average, coal 0.8%, oil 1%, gas 1.3%). In Europe, emissions from coal combustion are falling, but emissions from oil and gas are rising.

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

Trend in land use emissions is declining

In contrast to fossil emissions, researchers predict a downward trend for emissions from land use. According to preliminary data, total emissions from land use change in 2025 will amount to 4.1 billion tons of CO2, slightly less than in 2024. "The decline 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 assessment of land use emissions at LMU together with Dr. Clemens Schwingshackl. "Deforestation rates in the Amazon region have declined and are at their lowest level since 2014 this season."

The ocean sink has largely stagnated since 2016

Over the past ten years, the oceans have absorbed 29% of total CO2 emissions. "This makes the ocean the largest natural sink for man-made CO2 emissions," says Professor Judith Hauck, environmental researcher at the AWI, who coordinated the assessment of the ocean sink. However, since 2016, the ocean sink has largely stagnated, mainly due to climatic fluctuations that have weakened the previously increasing trend. It was also affected by the heat wave in the northern hemisphere's oceans in 2023-2024.

The absorption of CO2 from the atmosphere by land masses – the so-called terrestrial sink – suffered a sharp decline in 2024 due to El Niño. For 2025, the data show a recovery to the level before this climate phenomenon. "The devastating fires in 2024 showed how sensitive ecosystems are if we do not also limit global warming," Schwingshackl emphasizes. "Climate protection is also ecosystem protection."

About the Global Carbon Project

The GCP is an international research project of the Future Earth research initiative on global sustainability. An international team of more than 130 climate researchers compiles the report, which is updated annually—now for the twentieth time. This year's edition was presented on November 13, 2025, at the 30th UN Climate Change Conference in Belém. An accompanying publication explaining methodological improvements for the Global Carbon Project report appears in the journal Nature.

Scientists from the German-speaking region include researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (Bremerhaven), ETH Zurich, the Helmholtz Centre Hereon (Geesthacht), the International Institute for Applied Systems Analysis (IIASA), the Karlsruhe Institute of Technology, the Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Ludwig Maximilian University (Munich), the Max Planck Institute for Meteorology (Hamburg), the Max Planck Institute for Biogeochemistry (Jena), the Potsdam Institute for Climate Impact Research, and the Universities of Bern, Bremen, and Hamburg, which contributed to the report with ocean observations, model simulations of the ocean, land, and atmosphere, and analyses.