Delegates at the Cop26 climate summit should seek an agreement to ban the sale of petrol cars worldwide by 2035, a think tank has said.
The Energy Transitions Commission said a swift end for polluting cars was one of six measures that could keep the Paris Agreement targets alive.
The others include a faster coal phase-out and a cut in methane emissions led by the US, Canada, Russia and China.
A report written by dozens of energy industry insiders said cities could decide at local level when to end the use, rather than just the sale, of polluting cars.
Technological improvements “make it possible to drive road transport electrification far more rapidly than seemed feasible five years ago”, it said.
Setting a 2035 deadline for sales could lead to one in five cars on the road being electric by the end of this decade, the experts said.
They said this could save about two billion tonnes of carbon dioxide a year, and perhaps more if there is progress on heavy-duty vehicles.
“A strong agreement to commit to ending sales [of petrol cars] by 2035 at the latest is therefore a crucial Cop26 priority, supported by clear targets from countries and car manufacturers,” they said.
The panel said quick action was necessary to maintain hopes of limiting global warming to 1.5°C above pre-industrial levels. This is the aspiration of the Paris Agreement.
A landmark UN report published in August said that the effetcs of climate change would be far more severe if the 1.5°C target is breached. Climate activist Greta Thunberg this week condemned what she called the "blah, blah, blah" of pledges made by world leaders.
Britain has a 2030 deadline to stop the sale of polluting cars. The EU is looking at 2035. Germany’s plans may depend on the outcome of coalition talks involving the Green party.
The UK says it wants to use its presidency of Cop26 to push other countries to move faster towards electric cars.
In the US, President Joe Biden wants half of vehicles sold in 2030 to be electric. California has gone further with a ban on polluting cars by 2035.
Another measure favoured by experts is a quick exit from coal, which has been a thorny subject in global talks.
The think tank said that coal-fired stations accounted for about three quarters of the power sector’s emissions in 2019.
Cop26 delegates should agree to build no new coal plants and put a stop to plans that are in the pipeline, the panel said. Moving quickly away from coal is “one of the highest potential actions to reduce emissions in the short term,” it said.