Green hydrogen (GH2 or GH2) is hydrogen generated by renewable energy or from low-carbon power. Green hydrogen has significantly lower carbon emissions than grey hydrogen, which is produced by steam reforming of natural gas, which makes up the bulk of the hydrogen market. Green hydrogen produced by the electrolysis of water is less than 0.1% of total hydrogen production. It may be used to decarbonize sectors which are hard to electrify, such as steel and cement production, and thus help to limit climate change.