Route of all good

Which of these will save the world? Speed cameras on every road. A gauge on every dashboard showing real-time exhaust emissions. A market in which car makers buy and sell carbon quotas. These are suggestions from academics, specialists and policy pundits to help stop climate change. Can they be serious?

They certainly are. The policies have been selected by the Low Carbon Vehicle Partnership, from more than 30 submitted, as worthy of consideration. The UK government aims to reduce carbon dioxide emissions by 60 per cent by 2050 and road transport contributes around a quarter of CO2. So slash vehicle carbon emissions and our culpability for global warming will be similarly reduced.

But how can that be achieved? Routes that had seemed promising, such as road charging, hydrogen fuel cells and the promotion of new, cleaner technologies, have been diverted into lay-bys. Road charging might smooth the peaks and troughs in traffic flow but do little to reduce overall emissions. Besides, the abandonment last year of the planned trial to charge lorries is seen as a major setback to pay-per-mile projects. Progress now seems stalled until standards for road-charging systems are harmonised across Europe.