Researchers have detailed the geological ingredients required to find clean sources of natural hydrogen beneath our feet. The work details the requirements for natural hydrogen, produced by the Earth itself over geological time, to accumulate in the crust, and identifies that the geological environments with those ingredients are widespread globally. Hydrogen is 135billionindustry,essentialformakingfertilizerandotherimportantsocietalchemicals,andacriticalcleanenergysourceforfuturelowcarbonemissiontechnologies,withamarketestimatedtobeupto135 billion industry, essential for making fertilizer and other important societal chemicals, and a critical clean energy source for future low carbon emission technologies, with a market estimated to be up to 1000 billion by 2050. These findings offer a solution to the challenge of hydrogen supply, and will help industry to locate and extract natural hydrogen to meet global demands, eliminating the use of hydrocarbons for this purpose.