Mr Red, re my post on batteries and your response. Not for a second was I suggesting that avoiding the inconveniences of limited range and recharging time trumps the need to change our behaviour. I am suggesting that those inconveniences (plus the expense of battery cars) are major obstacles in persuading people to change. Governments can force people to change, of course, by setting unrealistic time scales (end of austerity by 2015, anyone?), and once they force us all to buy battery cars there'll be another inconvenience, this time for petrol drivers in their bangers, in that it'll get harder and harder to find petrol stations. But governments forcing major changes on people tend to make themselves very unpopular...