The World Meteorological Organisation (WMO) said average carbon dioxide concentrations reached 426.8 parts per million, equivalent to 153% of pre-industrial levels recorded in 1750. “Every additional part per million matters because it traps additional heat,” WMO Deputy Secretary-General Ko Barrett said.

“In effect, we are supercharging the ocean and the atmosphere. That means heatwaves, tropical cyclones and rainstorms are intensifying faster than our historical baselines prepared us for.”

Carbon dioxide concentrations stood at 377.5 parts per million when WMO first published the Greenhouse Gas Bulletin in 2004.

Annual carbon dioxide growth has tripled since the 1960s, increasing from an average of 0.8 parts per million annually to 2.4 parts per million between 2011 and 2020.

Concentrations increased by another 2.8 parts per million between 2024 and 2025, largely because of fossil-fuel use.

WMO Senior Scientific Officer Oksana Tarasova warned that concentrations could rise further in 2026 as fossil-fuel consumption continued and a powerful El Niño weakened forests and other natural carbon sinks.

About half of the carbon dioxide released annually remains in the atmosphere. Land ecosystems and oceans absorb the remainder.

The warming effect of greenhouse gases increased by 56% between 1990 and 2025, with carbon dioxide responsible for about 81% of the rise. “Another year, another new record,” Barrett said.

“The past 11 years have been the warmest on record, and this trend is set to continue.”

WMO also warned about sulphur hexafluoride, used in electricity distribution, and hydrogen leakage linked to emerging energy systems.

Sulphur hexafluoride has an atmospheric lifetime exceeding 1 000 years and a 100-year warming potential about 24 300 times greater than carbon dioxide.

Hydrogen is not a greenhouse gas but can indirectly contribute to warming by affecting atmospheric chemistry.

WMO said careful monitoring was essential to prevent unintended environmental consequences from undermining the benefits of the global energy transition.

–UN/ChannelAfrica–