Supply of Hydrogen : Constant increase in the production of green hydrogen(a type of hydrogen fuel that is produced using renewable energy sources, such as wind, solar, or hydroelectric power) worldwide will reduce the cost of hydrogen. Hydrogen will never be depleted, and its supply is not bound to specific regions like petroleum. Given the right infrastructure, hydrogen can be produced anywhere there is water. 

High Energy Density: One of the most significant advantages of hydrogen is its high energy density per unit mass, which is about three times higher than that of traditional jet fuel. This means that, for the same amount of energy, hydrogen is much lighter to transport in an aircraft, potentially leading to increased efficiency and longer flight ranges.

Zero Carbon Emissions: Hydrogen propulsion systems do not generate carbon dioxide (CO2) during flight. When hydrogen is burned in aero engines or used in fuel cells to generate electricity for powering aircraft propellers or fans, the primary byproduct is water, leading to substantial reductions in greenhouse gas emissions.