What if we run out of hydrogen?
Solar and wind are great at producing hydrogen via electrolysis. Hydrogen as a storage medium for use in automobiles and much more.
I assume you’re being sarcastic, but that would mean using up all the water in the world. Also, the main byproduct of using hydrogen tends to be water, so..
Peak hydrogen...
NASA can make supply and refueling runs with the Sun. There's lots there. Little warm though.
If you use atmospheric air as the oxygen source, there would be some NOx formation as a side product.
“What if we run out of hydrogen?”
Don’t mention this to Al Gore. We’ll have a brand new movement on our hands. They’ll be chaining themselves to the ocean. Hmmm.