> burning fossil fuels release carbon dioxide and water vapour Either I have completely misunderstood something, or fossil fuels release only CO2 and H2O under

> burning fossil fuels release carbon dioxide and water vapour Either I have completely misunderstood something, or fossil fuels release only CO2 and H2O under ideal conditions, which never happens. Add to the fact that any jet engine is unable to utilize any after treatment systems to remove harmful products. I am fully aware that hydrogen is rather expensive to produce, but I think it's possible that nuclear energy, or (as you mention) excess solar/wind power is several magnitudes cleaner than even the cleanest burning fossil fuel engine (including all the resources it takes to pump it up and refine it).