Hydrogen production has been dominated by gray hydrogen (hydrogen produced from fossil fuels without carbon capture). Historical data for 2019–2021 show nearly steady global production and demand of hydrogen, with an average annual of 92 Mt (million tonnes) for either production or demand. Each of the global hydrogen production or demand should grow to 180 Mt in 2030 for compliance with the Net Zero Emissions by 2050 scenario (NZE) of the International Energy Agency (IEA), to bring CO₂ emissions to net zero by 2050. Recently, green hydrogen (hydrogen produced by water electrolysis using electricity from renewables) received attention, with 11 countries (Australia, United States, Spain, Canada, Chile, Egypt, Germany, India, Brazil, Oman, and Morocco) identified as expected top producers may produce together 15.9534 Mt in 2030. All of these countries except Spain, Canada, and Germany, were classified by the global Hydrogen Council as having optimal production potential of green hydrogen. Blue hydrogen (hydrogen produced from fossil fuels with carbon capture) and green hydrogen together form clean hydrogen. The share of clean hydrogen in the global total final energy consumption (TFEC) was less than 0.1% in 2020. In alignment with the 1.5 °C pathway of the International Renewable Energy Agency (IRENA) to limit the global average temperature rise to 1.5 °C above pre-industrial levels, this share should grow to 3% in 2030 and 12% in 2050, with 154 Mt of clean hydrogen and its derivatives produced in 2030 (and 614 Mt in 2050), compared to only 0.8 Mt in 2020.