York, England - Technological advances mean fossil fuel in cars could be phased out within decades but switching to electric carries its own environmental and economic concerns as more and more countries announce radical plans.
Britain on Wednesday said it would "end the sale of all conventional petrol and diesel cars" by 2040, following similar proposals by France earlier in July to reduce nitrogen dioxide pollution.
China issued plans in 2016 requiring that 12 percent of cars sold be battery-powered or plug-in hybrids by 2020, while India has said it wants to replace all vehicles with electric vehicles by 2030.
Norway hopes to end sales of new petrol and diesel cars by 2025, and other countries such as Sweden and Denmark and Finland have expressed similar ambitions to phase out fossil fuel engines.
'Highly symbolic'
Alastair Lewis, professor of atmospheric chemistry at the University of York, said: "Given the rate of improvement in battery and electric vehicle technology over the past 10 years, by 2040 small combustion engines in private cars could well have disappeared without any government intervention.
"Nonetheless this is highly symbolic," he added, "since it signals to both the public and to manufacturers that there is no turning back from electrification.
Stefan Bratzel, director of the Centre for Automotive Management said 2016 proved to be a "tipping point", shifting political will into concrete commitments.
He highlighted the emissions scandal, where manufacturers of mainly diesel cars were found to have cheated on environmental tests.
Local and national environmental targets and the progress made by China in developing electric cars are also forces propelling the move away from hydrocarbons.
'A bold bet'
But Flavien Neuvy, economist at French automobile analyst Observatoire Cetelem, said it would be a "bold bet" to suggest that the roads will be filled with only electric cars by 2040.
"To say that we forbid combustion engines in 2040 assumes that we already know which will be the most efficient technology in 2040," he said.
"That's a bold bet because the combustion engine, from an environmental point of view, may become more favourable, as can be seen with cars that can now travel 100km on two litres of fuel".
He also believes that the electric car "will be much more efficient than today", and that an improvement from the current average range of 250-300km to 400-500km would be "enough" to make them viable.
"But in reality, there are many other fuels, such as liquified natural gas and hydrogen - and manufacturers are investing heavily in autonomous cars," he added.
Incentives
Cost is also an issue, with electric cars currently selling for thousands of dollars more than their fossil-fueled counterparts.
The fashion for diesel cars in Britain was fueled by government incentives to reduce carbon emissions, but only worsened NO2 levels on a more local level - and a switch to electric cars could also have negative environmental side effects, experts say.
Neuvy questioned how the extra electricity would be produced, whether there were enough resources to produce electric batteries, how many charging points would be needed and how the cars would be recycled.
Britain has about 4500 public charging points now, catering for about 110 000 plug-in cars currently on the streets out of a total of 36.7 million registered vehicles.
A study in June by Swedish Environment Institute IVL found that making a large battery results in the emission of up to 17.5 tons of carbon dioxide, equivalent to about 700 hours of driving in an average car.
Another stumbling block could be the vast infrastructure costs associated with providing recharge points on public highways, although Britain's plan promises to install charge points at motorway service areas and large fuel retailers.
British car manufacturing lobby group the Society of Motor Manufacturers and Traders also warned that an outright ban "risked undermining the current market for new cars", pointing out that the sector employs 800 000 workers.
But for now, the momentum appears to be strong, particularly if oil prices rise again.
The Centre for Automotive Management predicts that new registrations of electric cars worldwide will increase by between 2.5 and six percent by 2020. "A big offensive by manufacturers" would then lead to a 40 percent increase by 2030.