WMO reports a new record in atmospheric carbon dioxide

The globally averaged surface concentration of atmospheric carbon dioxide rose to 426.8 ppm in 2025, a new record according to the WMO’s report of 27 October. The shared atmospheric background matters for Hungary; planning domestic water management and agricultural adaptation also requires local observations.

The figure in the original WMO statement is also reported by AFP. Concentration expresses the proportion of gas accumulated in the atmosphere. An emissions inventory instead counts quantities released over a period; the two indicators answer different questions.

Our reader guide suggests recording climate data with three labels: what it measures, which period it covers and what area it represents. A global average does not provide a municipal forecast. An irrigation decision at a Hungarian farm, for example, also needs soil conditions, water availability and local weather information; we do not calculate such operational parameters from the global average.

The EU climate-risk proposal addresses institutional preparedness, while the EU–UNEP partnership describes international cooperation. These are separate stories from the newly released measurement. New observations from the monitoring network and the next annual report can show how the trend continues. Consistent comparison between successive releases requires the same measurement coverage and methodology.

The year label also matters: the newly published figure summarises an earlier complete year. The release date and observation period are identified separately in this report.