Scientists think a hidden source of clean energy could power Earth for 170,000 years — and they've figured out the 'recipe' to find it

An active fumerole in Iceland spews hydrogen sulfide gas.

Recent breakthroughs suggest that hydrogen reservoirs are buried in countless regions of the world, including at least 30 U.S. states.

Finding such reservoirs could help accelerate a global energy transition, but until now, geologists only had a piecemeal understanding of how large hydrogen accumulations form — and where to find them.