Offering motorists cash to give up petrol-powered cars may encourage some to go electric.
But it won’t result in the widespread shift in attitudes which Ministers may be hoping for.
What might prompt motorists to change their habits is the widespread availability of electric cars which are affordable, reliable and fast.
Most drivers don’t expect tyre-burning performance from a vehicle, but they want something that can reach a reasonable speed and gets them to their destination without breaking down because the battery is flat.
In other words, appealing to people’s better nature and sense of care towards the environment is not going to be enough. Motorists will only pay good money for good cars.
Backing manufacturers who invest in new technology may have more effect in the long run than offering incentives to individual car-buyers.
There is, however, another essential element, which is the provision of power-points allowing drivers of electric cars to recharge their vehicles.
This is something local and national government working together would need to provide, with councils providing leadership and Whitehall making money available.
London is already pursuing this path, after city mayor Boris Johnson unveiled plans for a recharging point on every block.
Birmingham could decide to go down the same route, potentially improving local air quality and proving that the West Midlands really is a world leader in adopting environmentally-friendly technology.
But the city would be taking a gamble that electric cars are ever likely to catch on. There’s no guarantee that motorists will embrace the concept just because green campaigners feel they ought to. And some environmentalists argue that a better solution to the problem of pollution is to get people out of their cars entirely and into trams and buses.
This is one of the issues raised by a new report by think-tank the Centre for Cities, which urged ministers to free up more than £1 billion currently reserved for road pricing schemes.
This cash was supposed to pay for public transport improvements in regions where councils decided to introduce congestion charging.
But as the think-tank points out, no local authority has done this – and they probably aren’t going to.
The Government has two choices. It should either admit defeat on this one, and make the money available anyway.
Alternatively, it could take the politically dangerous step of imposing road pricing on unwilling populations. What Ministers must surely have realised by now is that local authorities are not going to embrace charges voluntarily.