Donuel, you're cavilling. The point is that there's a huge difference between recycling stored fossil energy (which releases CO2 into the atmosphere) and using sources of energy that are derived from outside the Earth (wind/ tidal = solar), or using energy from nuclear reactions, both of which don't add to the CO2. the problem with current fission solutions is that they add to something else instead.

So hydrogen, whether converted in fuel cells or burnt directly in an IC engine, is merely a means of transmitting the energy from the site of production (by whatever means) to the point where the energy is used. Unless we find a reservoir of molecular hydrogen somewhere on Earth, it can't generate anything.

Having said that, its flexibility- you can make hydrogen from anything from a waterwheel or a bicycle to a nuclear power station- makes it very attractive as a storage medium for low- grade alternative production sources. If we can keep it from blowing up.