Transportation Infrastructure, NH3
To reiterate, cars can run longer range on same amt of fuel with H2 than gasoline.
Tank is filled in 5 minutes.
Hydrogen Fuel cell tech is already here.
H2 can be produced at gas stations.
If not, the fuel can be transported to stations in order to get the benefits of scale. Transporting hydrogen was somewhat harder, but with the CSIRO invention mentioned above H2 can simply be taken out of NH3, on site. Where does the ammonia come from? Ammonia is already produced in huge amounts in our economy, transported easily as liquid at room temparature. We do need to make sure tho the production of ammonia is green as well, but this is already doable.
All this sounds like a major slam-dunk. What remains is enterpreneurial, policy push to implement it at scale. CSIRO probably has a patent on the NH3/H2 seperation tech, a company perhaps previously in gasoline business can to go into partnership with them (patents suck, yes).
Countries with lots of sunshine, Australia, Saudi Arabia, can generate and export ammonia.
Countries like Russia generate hydrogen and pipe it through the same network used for natural gas. Britain has experiments underway to use H2 as heating at homes.
Then, maybe, hopefully we dont frickin die in a few decades, air and water is clean, no more wars to dig up some gunk from the soil.