65% of Londoners told YouGov there is a lot or a fair amount of climate disinformation on social media. Sadiq Khan takes the ULEZ row to COP31 in Türkiye.

Almost two-thirds of Londoners, 65 per cent, say there is “a lot” or “a fair amount” of climate disinformation on social media. The figure comes from a YouGov poll for City Hall, published on Thursday 12 November.

The Mayor of London, Sadiq Khan, is taking it to COP31, the United Nations climate conference in Antalya, Türkiye. His main example is the Ultra Low Emission Zone, which has covered the whole of Barnet since it was expanded across London in 2023.

The ULEZ row as a warning to world leaders

The Mayor says the 2023 expansion drew “one of the most sophisticated disinformation campaigns ever seen”. He is expected to tell world leaders:

“While we act on the scientific consensus, the climate deniers and delayers are playing dirty with one last trick up their sleeve: climate disinformation. London is no stranger to lies. When we expanded our clean air zone, now the largest in the world in 2023, we faced one of the most sophisticated disinformation campaigns ever seen. We overcame it and won. But evidence from all five continents shows London was just the canary in the coal mine.”

City Hall points to a 2023 investigation by the social media analysts Valent Projects. It found:

  • around 3,700 apparently inauthentic accounts amplifying posts against the ULEZ expansion on X, then called Twitter
  • an operation that cost at least £168,000 on X alone, judged by the price of buying followers and automation software
  • no answer to who was behind it: the investigation did not establish that

What the poll asked

YouGov surveyed 1,128 London residents aged 18 and over between 16 and 25 October 2026. The answers were weighted to represent all London adults. City Hall has not published a borough breakdown, so there is no separate figure for Barnet.

The first Mayor of London on the COP main stage

City Hall says Sadiq Khan will be the first Mayor of London to speak at the World Leaders’ Summit at a COP. He will address leaders from the main stage, a slot usually kept for heads of state and government leaders. He is there as elected co-chair of C40, the network of global cities, and will urge governments to work with cities against climate disinformation.

He describes it as “a one-two punch to the planet and democracy”. He is expected to say: “Here in Türkiye, we’re calling on the world to get its guard up to defend itself and mount a comeback, to deal a knockout blow to the dark forces distorting debate.”

The evidence he will cite

The Mayor’s case rests on a study of children’s lungs. The Children’s Health in London and Luton (CHILL) study was led by Queen Mary University of London, funded by the National Institute for Health and Care Research and published in The Lancet Public Health.

It followed more than 3,400 primary school children for five years after the ULEZ first arrived in central London in 2019, using Luton as a comparison. The study linked cleaner air to faster lung growth:

  • in the London group, the share of children with clinically impaired lung function fell from 14 to 9 per cent
  • in the Luton group, it fell from 9 to 7 per cent

The children studied were in central London and Luton, not outer boroughs such as Barnet. City Hall also estimates that roadside nitrogen dioxide in central London is 54 per cent lower than it would have been without the ULEZ and its expansions. That figure comes from a separate assessment, and it too covers central London only.

Air quality remains a live issue in Barnet. The borough was under a high air pollution alert on Tuesday 10 November.

The other figures City Hall is putting forward

City Hall lists what it says climate policy has delivered across London since Sadiq Khan was elected:

  • more than 3,000 zero-emission buses in the fleet
  • over 640,000 trees planted with Mayoral funding
  • 900 hectares of green space created or improved
  • 193,700 tonnes of CO2 saved from new buildings between 2021 and 2025 through London Plan policies, which City Hall puts at the equivalent of 164,000 return flights from London to New York

London’s green economy generated £54.9 billion in sales in 2023 to 2024, according to the London Low Carbon Market Snapshot 2025. More than 20,000 businesses in it employed over 341,000 people. The figures cover low-carbon and environmental goods and services firms, with sales used as a measure of the sector’s size.

The Mayor is expected to add: “We often talk about climate action as if it were a question of sacrifice. But look at what we’ve delivered: health, happiness, and opportunity, not in some distant decade but right now.”

He is expected to close: “It’s time to resist the attacks and stand up for the facts, with a relentless focus on unlocking the finance and expertise we need to fund climate action and adaptation around the world. London and other great cities around the world are showing we can overcome this challenge, we can win this fight and we can create a fairer, greener, healthier and more prosperous planet for everyone.”

The full release is on the Mayor of London’s press pages.