Prime Minister Boris Johnson announced on Tuesday that Britain will ban sales of new petrol, diesel, and hybrid vehicles starting from 2035, five years earlier than previously planned.
Britain has pledged to reduce greenhouse gas emissions to net zero by 2050, with a mixture of cuts and off-setting pollution measures such as planting trees.
The summit, known as COP26, is being hosted in Glasgow. It is an annual UN-led gathering set up to assess progress on tackling climate change.
The government’s plans come as COP26’s former president Claire O’Neill, who was sacked on Friday, wrote a bitter letter accusing Mr Johnson of failing to support her work.
At a launch event in London the prime minister will say the ban could come even earlier than 2035 for new petrol and diesel cars, if possible.
“Hosting COP26 is an important opportunity for the UK and nations across the globe to step up in the fight against climate change,” Johnson said.
“As we set out our plans to hit our ambitious 2050 net zero target across this year, so we shall urge others to join us in pledging net zero emissions.
“2020 must be the year we turn the tide on global warming — it will be the year when we choose a cleaner, greener future for all.”
At the COP26 launch event in London, Johnson was to be joined by Italian Prime Minister Giuseppe Conte and naturalist David Attenborough.
Johnson will urge other countries to join Britain in striving toward the 2050 net zero emissions goal through investment in cleaner technology and efforts to protect natural habitats.
Edmund King, president of Britain’s AA motoring association, said the new target on car sales was incredibly challenging.
“We must question whether we will have a sufficient supply of a full cross-section of zero emissions vehicles in less than 15 years,” he said.
He also urged the government to cut the sales tax on electric vehicles to make them more affordable.