Cop26 President Alok Sharma has a “Herculean” task to make the summit a success, the Prime Minister’s father Stanley Johnson said.

Mr Johnson said persuading China to commit to more ambitious targets – something it has declined to do in the build-up to the Glasgow Cop26 summit – would be the key to making progress.

He said the role of the UK, led by his son Boris Johnson, would be “crucial” as the host of the summit.

“Realistically, Alok Sharma MP, as president designate of COP 26, has a Herculean task on his hands,” Mr Johnson said.

“His most important job is to persuade governments around the world to strengthen their emission reduction programmes for 2030. This is the decade that counts if we are to close the gap.”

But in a paper published by the UK Energy Security and Resilience Group, Mr Johnson argued that Cop26 could go a step further if it met one of the Government’s stated goals of a global commitment to net zero carbon emissions by 2050.

“There is no doubting the Prime Minister’s own commitment,” Mr Johnson said of his son.

But “realistically, much depends on China” and decisions made by Xi Jinping – who will not attend the summit in person – will “determine whether or not Cop26 will be seen as a success”.

He said if China does not object to a global 2050 target and commits to faster progress to “peaking” its own emissions, then “the whole atmosphere at Glasgow would surely be transformed”.

In the run-up to the summit, China has recommitted to reach carbon neutrality before 2060, peak emissions before 2030, and lower carbon emissions per unit of GDP by over 65% from the 2005 level.

And it plans to increase the non-fossil fuel share of energy consumption to 25%, increase forests and bring its installed capacity of wind and solar to more than 1,200 gigawatts (GW) by 2030.