[Little Pig]

Excluding any pollution caused by isolating the hydrogen, the only byproduct of hydrogen oxidation (burning) is water vapor.

Of course, water vapor is the most prevalent “greenhouse” gas, but don’t tell Al Gore that.

[Travis T. OJustice]

Excluding any pollution caused by isolating the hydrogen,

LOL! There's the rub!

[Danae]

Water vapor is literally the Only Greenhouse gas that matters.