A global gold rush for buried hydrogen is underway — as hype builds over its potential energy source. Geologic hydrogen (or gold) refers to hydrogen gas found in its natural form beneath the earth's surface but most is produced using fossil fuels such as coal and natural gas — a process that generates significant greenhouse gas emissions. Green hydrogen, a process which splits water into hydrogen and oxygen using renewable electricity, is one exception to what’s known as the hydrogen color rainbow. Currently, momentum is building Source