Something to keep in mind when hearing about hydrogen as a renewable or green fuel is that nearly half of hydrogen production, worldwide, comes from natural gas. Another 45% or so come from coal and oil sources. Renewable hydrogen - electrolysis, generally - is basically a blip.
Hydrogen is, in many cases, an attempt _by the fossil fuels industry_ to carry on business as usual in the face of carbon-reduction initiatives by putting the carbonaceous parts out of sight.