October 15, 2025

expert reaction to World Meteorological Organization Greenhouse Gas Bulletin

Scientists comment on the World Meterological Organisation’s (WMO) Greenhouse Gas Bulletin that shows CO2 levels in the atmosphere are at a new high.

Dr Phil Williamson, Honorary Associate Professor, University of East Anglia, said

“It was inevitable that the World Meteorological Organization would report a record high in CO2 levels for 2024: when we add more to the atmosphere, most of it stays there and its concentration therefore increases.  What’s new – and scary even for climate scientists – is that the rate of that increase has accelerated at a time when annual fossil fuel emissions have stayed much the same.  That means that the balance of removals and additions in the natural climate system is also changing, with worldwide forest fires and warming seas now providing a positive feedback to global heating.  This effect isn’t just a one year anomaly; growth rates of CO2 have tripled in recent decades.  The clear message is that it is getting harder all the time to bring climate change under control, yet more necessary than ever that we do so.”

Dr Ali Mashayek, Associate Professor, Department of Earth Sciences, University of Cambridge, said:

“Lack of sustained monitoring and observational gaps compromise advancing our understanding of the marine physical and biogeochemical processes that drive the oceanic carbon uptake, a primary sink of anthropogenic atmospheric Co2. So, I agree with the report’s call for strengthening of monitoring capabilities.”

‘WMO Greenhouse Gas Bulletin – No. 21’ was published by the World Meteorological Organization on Wednesday 15 October 2025.

https://wmo.int/publication-series/wmo-greenhouse-gas-bulletin-no-21

Declared interests

Dr Phil Williamson: No COIs.

For all other experts, no reply to our request for DOIs was received.