Britain plans to ban the sale of new petrol and diesel cars by 2035 – five years earlier than its previous target – in a bid to speed up efforts to tackle climate change.

But the UK government’s commitment to reducing greenhouse gas emissions was questioned by the woman who was appointed by Prime Minister Boris Johnson to head a United Nations’ global climate summit – and then was fired last week.

Sacked conference president Claire O’Neill said Britain’s efforts to fight climate change were “miles off track.”

Britain has pledged to reduce its net greenhouse gas emissions to zero by 2050. But the government’s advisory Committee on Climate Change has warned that domestic action to slash carbon dioxide and other gases that contribute to global warming is lagging far behind what is needed.

• Related: UK hits renewable energy milestone

The UK’s new 2035 target for ending gas and diesel sales is one of the world’s more ambitious.

Several countries including France plan to stop by 2040. Norway – one of the most aggressive early adopters of electric cars – has a goal, but not a requirement, to eliminate gas and diesel cars, excluding hybrids, by 2025.

Boris Johnson (standing alongside Italian Prime Minister Giuseppe Conte) reiterated the government’s commitment to net-zero by 2050. Photo: AAP

But environmental groups said Britain’s goal was not ambitious enough.
Rebecca Newsom, head of politics at Greenpeace UK, said “phasing out the internal combustion engine faster is an important piece of the puzzle.”

“However, pushing the date later than 2030 would vastly reduce the chances of meeting our climate targets, and the potential to deliver thousands of electric vehicle manufacturing jobs,” she said.

The UK says it will bring in a ban on fossil-fuel cars and vans even earlier than 2035 “if a faster transition is feasible”. The ban will also include hybrid vehicles.

The auto industry reacted coolly to the announcement. Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders, said the automakers were already moving toward “a zero-emissions future,” and said the government had “moved the goalposts for consumers and industry”.

The announcement was timed to coincide with the launch of Britain’s plans for the climate summit, known as the 26th Conference of the Parties, or COP26. It is scheduled to be held in Glasgow in November.

Mr Johnson kicked off a year of build-up Tuesday alongside naturalist David Attenborough and Italian Prime Minister Giuseppe Conte at London’s Science Museum. Italy is hosting a preparatory meeting for the conference.

The British prime minister said the world had seen “a catastrophic period of global addiction to hydrocarbons that got totally out of control”.

“We have to deal with our CO2 emissions, and that is why the UK is calling for us to get to net-zero as soon as possible, to get every country to announce credible targets to get there – that’s what we want from Glasgow,” Mr Johnson said.

“And that’s why we have pledged here in the UK to deliver net-zero by 2050.”

Britain’s tenure at the helm of COP26 is getting off to a rocky start. On Friday, Mr Johnson sacked Ms O’Neill, a former British government minister appointed last year to head up the event. Her replacement has not been announced.

-AAP