The study lays out the geological conditions needed for hydrogen to form and collect underground, and argues those conditions exist widely across the planet rather than in a handful of rare pockets. Chris Ballentine of Oxford University, one of the researchers behind the work, said combining the right geological ingredients to find hydrogen "can be compared to preparing a soufflé." The reserves are not permanent once discovered: microbial activity underground can consume and deplete them over time.

The case for a global search was strengthened by a discovery in France's Moselle region, where a reservoir now estimated to hold 46 million tonnes of hydrogen was found. For comparison, the world consumed roughly 90 million tonnes of hydrogen in 2022. Most of that supply is "grey hydrogen," produced from fossil fuels in a process that emits close to 10 kilos of carbon dioxide for every kilo of hydrogen made.

Natural hydrogen would skip that emissions step entirely, offering a lower-carbon supply for industries and transport that rely on the gas. Exploration is already underway in Australia, the United States, and France. French authorities issued permits for natural hydrogen exploration in the Pyrénées-Atlantiques and Landes regions in late 2023.

The research team behind the Nature Reviews Earth & Environment study has set up its own exploration company to search for deposits that could be extracted commercially.