The findings are relevant for hydrogen-based fuel cycles, say the researchers. Limiting leaks from future hydrogen fuel projects and cutting methane emissions will be key to securing benefits from hydrogen as a clean-burning alternative to oil and gas.  

Stanford University scientist Rob Jackson, senior author of the article, said: ‘The best way to reduce warming from hydrogen is to avoid leaks and reduce emissions of methane, which breaks down into hydrogen in the atmosphere.’ Since 1990, the authors estimate the annual emissions from this source of hydrogen have grown by about 4 million tonnes, to 27mn t/y in 2020.

Unlike greenhouse gases including CO₂ and methane, hydrogen itself does not trap heat in Earth’s atmosphere. Through interactions with other gases, however, hydrogen indirectly heats the atmosphere roughly 11 times faster than CO₂ during the first 100 years after release, and around 37 times faster during the first 20 years, they report.

This is primarily by consuming natural detergents in the atmosphere that destroy methane.

‘More hydrogen means fewer detergents in the atmosphere, causing methane to persist longer and, therefore, warm the climate longer,’ said lead study author Zutao Ouyang, an assistant professor of ecosystem modelling at Auburn University.

In addition to extending the heat-trapping life of methane, hydrogen’s reactions with nature’s detergents also produce greenhouse gases such as ozone and stratospheric water vapour, and affect cloud formation.

Soils have removed about 70% of hydrogen emissions since 1990, mostly through the action of bacteria.

Overall, the buildup of hydrogen in the atmosphere has contributed a fraction of a degree (0.02°C) to the nearly 1.5°C increase in average global temperatures since the Industrial Revolution, the authors estimate.

The Nature article, The global hydrogen budget, is said to be the first comprehensive accounting of hydrogen sources and sinks.

The authors of the paper also publish the Global Carbon Budget. Its last edition, released on 13 November 2025, projected that total fossil CO₂ emissions in 2025 would amount to 38.1bn tonnes, up 1.1% on 2024, to a new record high.

At that time, Professor Pierre Friedlingstein, of Exeter’s Global Systems Institute, who led the study, said: ‘With CO₂ emissions still increasing, keeping global warming below 1.5°C is no longer plausible. The remaining carbon budget for 1.5°C, 170bn tonnes of CO₂, will be gone before 2030 at current emission rate. We estimate that climate change is now reducing the combined land and ocean sinks – a clear signal from Planet Earth that we need to dramatically reduce emissions.’