Making cars more efficient will not necessarily curb our emissions

It is safe to say that the German carmakers will be looking less jolly than usual this Weihnachtszeit . The European Commission has just unveiled its proposals for reducing vehicle carbon emissions; from 2012 new cars will be permitted to emit no more than an average level of 130 grams of carbon dioxide per kilometre. If this target is not met manufacturers will face stringent and mounting financial penalties.

But if German carmakers like Mercedes, BMW, Porsche and Audi are fee...