The Lib Dems want to ban all UK petrol and engine cars from 2040. Backed by Lib Dem president Tim Farron, the change in the law could even be brought forward, if electric car and hybrid development tech surges faster than present levels. Their new manifesto also backs more congestion charging and public transport. Are the Lib Dem manifesto promises right, or realistic?
Too earlyPaul Watters from the AA doesn't think the Lib Dems are either. "You can't just ban petrol and diesel cases on a particular date," he told AOL Money. "It would need to be an evolution rather than a revolution."
"You can't set a date until you really know the parameters of the technology. If you ask anyone with tech expertise in the industry, they'd say 2040 was premature."
Although some sixties and seventies cars survive now, most have succumbed to the rot. Cars built from hot-dip galvanised steel - the practice increased during the 1990s - stand a better chance. Unless, of course, electric gremlins get there first.
"We're making good strides on reducing CO2 and getting the tech out there, but electric vehicles don't supply the solution except for city dwellers," says Watters. "Will things have moved on sufficiently for the Lib Dems? I'm not sure."
100% renewableThe Lib Dems also want to replace air passenger duty with a per-plane duty, charged in proportion to a journey's carbon emissions; they also oppose any plans for extra runways at Heathrow, Gatwick and Stansted, or for a Thames Estuary airport.
But perhaps the biggest energy commitment change is 2050 - the target date by which all of the UK's electricity is generated from sustainable energy, "setting a target of 50 per cent of electricity generation from renewable sources by 2030 and putting in place a legally binding target for the decarbonisation of the electricity sector."
Lib Dem party president Tim Farron claims if the UK economy "is not green, it will be neither competitive nor successful." Download the manifesto here.