I've just got a few questions. I don't much believe in human carbon emissions having an appreciable effect on worldwide climate, but if carbon is causing any greenhouse effect, won't clouds of water vapour be even worse? Water vapour is certainly preferable to smoke in busy traffic. But wouldn't it still turn into a big - admittedly clean but still dark and grey - cloud of fog over heavily populated areas? Would all that damp cause problems to the surrounding buildings and infrastructure? I'm thinking for example of conservation isssues in historic buildings made of easily eroding stones.
Other than those practical problems, I am very happy with this news. I've always felt the current 'solutions' to the problem of people burning fossil fuels to drive cars around are ineffective and even counterproductive.
Electrical cars are available, but impractical. They are small and can't drive long distances. So they're fairly useless for most real families. You can't use one to get two children and your luggage to the beach for a weekend break. Charging them up takes too much time as well. Not to mention that it simply shifts the fuel-consumption problem as you charge it with electricity made in primarily coal-fired plants.
A lot of the same problems occur with hybrid cars. There's not a single hybrid people carrier, and on a long haul, you'd need a lot of fuel anyway.
And there's another problem with trying to change the way people drive by changing the way their cars work. It's slow and has the most succes with the wrong people. Electrical and hybrid cars are incredibly expensive. Most families could not possibly afford to upgrade to one, especially not while the car they own right now is so incredibly expensive to run. Raising fuel prices through taxes only reinforces this cycle (it really isn't going to stop people using their cars, obviously!). As long as I'm driving my 'old' car, I spend so much money on it, I'll never save up enough for a new one. Only a few people can afford to buy electrical or hybrid cars, therefore it will remain a luxury article. It may well be that once you have such a car, it 'pays for itself' in saved fuel, but the majority can't afford the initial outlay.
Usually, going green means paying extra, and often it means sacrificing something (comfort, convenience...). That's why it's hard to really do it succesfully. I want to look after my planet, but I also have practical needs to use my car. To really make a change, you've got to produce something that people can switch to easily, and that can be mass-marketed and mass-distributed. If I can simply drive up to the pump in my old car and choose between Diesel at £1.50/l or Hydrogen at £0.19/l, I know what I'll pick!
This is an innovation that makes ecological, economical and social sense! I'm all for it.