An unpublished report from the US Geological Survey (USGS) — an agency of the US government — has found that there are as much as five trillion tonnes of natural hydrogen underground, USGS researcher Geoffery Ellis told a US conference last week, according to the Financial Times.

And just a fraction of that would be enough to meet global H₂ demand for years to come, Ellis told the American Association for the Advancement of Science annual meeting in Denver.

“Most hydrogen is likely inaccessible, but a few per cent recovery would still supply all projected demand — 500 million tonnes a year — for hundreds of years,” he said, during a preview of the USGC report at the conference.