Hydrogen can be used to fuel our autos. The internal combustion engine can be modified on existing cars to burn it. New ones would be produced using fuel cells with no combustion. The technology is proven and if mass produced fuel cells may become cheaper to produce than what we now have. Electricity is needed to produce hydrogen, but there are untapped forces of nature such as tides , wind, geo-thermal etc. that we could use.
Production and distribution. The big oil industry has no interest in doing this because they are making a killing (pun) overcharging us for what they now produce. To allow them to continue raising prices (some ecologists advocate this) is folly because their bottom line is all that they can see.
pdq is right in that there is much that we can do but we should focus on what makes the most sense.
To get agreement of all nations is next to impossible. The only body that can really exert any pressure is the UN and it has become rather gutless.