Fossil Emissions Dip Slightly in 2026, but Carbon Dioxide in the Air Keeps Climbing

Fossil fuel emissions of carbon dioxide look set to be 0.40% lower in 2026 than in 2025, according to preliminary figures in the Global Carbon Budget 2026, the annual carbon accounting submitted Nov. 10, 2026, by Pierre Friedlingstein of the University of Exeter and his co-authors. The range the authors put on that projection runs from 1.5% lower to 0.6% higher, so it spans no change at all.

The carbon dioxide already in the air keeps building up either way. The same preliminary figures have the concentration rising 2.2 parts per million to reach 427.7 parts per million, which is 54% above the pre-industrial level. The Global Carbon Budget is a yearly accounting of how much carbon dioxide human activity releases and where it goes, whether into the air, into the ocean or into plants and soils, and the authors write that quantifying it is needed to understand the global carbon cycle and to project future climate change.

For 2025, a completed year rather than a projection, the authors report fossil emissions 1.2% higher than in 2024 and total human-caused emissions of about 42.8 billion metric tons of carbon dioxide, a figure that includes emissions from land use such as clearing forest. They call the uncertainty on that land-use component persistently large, and say their comparison of methods still finds low agreement on how much carbon dioxide the land takes up.

The paper is a preprint under review at the journal Earth System Science Data and has not been peer-reviewed. Public comment on it is open until Dec. 17, 2026, with referee reports, community comments and the authors' replies posted on the same page.

The budget's component estimates run back to 1959, and the authors have posted the data behind this edition publicly.