There is an interesting research article that was published in 2002 called “Climate consequences of hydrogen emissions” by Ilissa B. Ocko and Steven P. Hamburg (https://doi.org/10.5194/acp-22-9349-2022).

The study highlights the overlooked and underestimated climate impacts of hydrogen emissions. The findings reveal that the scale of climate benefits or disbenefits of clean hydrogen alternatives depends on the emission rate. Higher-end emission rates (10%) in green hydrogen applications may only reduce climate impacts from fossil fuel technologies by half over the first two decades, challenging the perception that green hydrogen is climate neutral. However, over a 100-year period, climate impacts could be reduced by around 80%. Lower-end emissions (1%) have limited impacts on the climate across all timescales. For blue hydrogen, methane emissions can make hydrogen applications worse for the climate than fossil fuel technologies in the short term, but over a 100-year period, blue hydrogen offers climate benefits.

Preventing hydrogen from leaking into the atmosphere will be crucial and new large-scale facilities that promise carbon neutral operations need to be critically reviewed before they are allowed to operate.

Other articles about atmospheric impact of hydrogen:
https://www.gov.uk/government/publications/atmospheric-implications-of-increased-hydrogen-use
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1067144/atmospheric-implications-of-increased-hydrogen-use.pdf