Cleaner air for Londoners after Ulez - report

Pollution in London has reduced after the controversial expansion of the Ultra Low Emission Zone (Ulez), according to City Hall.

Levels of nitrogen dioxide (NO2) - a toxic gas that exacerbates asthma, impedes lung development, and raises the risk of lung cancer - across all of London is estimated to have decreased by 27%, the report found.

The zone, which aims to cut pollution by charging drivers of vehicles which do not meet emission standards, was expanded by London's mayor Sir Sadiq Khan to outer London in August 2023.

The Labour mayor praised the results while the Conservatives on the London Assembly said the data relied on "maybes, possibilities, assumptions, and straight up fantasy".

When the scheme was expanded, it sparked protests as opponents said the scheme was rushed and the benefits were not worth the financial cost for those who had to change their vehicles.

Opponents also said the changes would have happened anyway as drivers took notice of the existing Inner London Ulez zone.

According to the study, which looked at data for 12 months from September 2023, air quality has improved at 99% of air quality monitoring sites across London since 2019, and London's air quality is improving at a faster rate than the rest of England.

It also found:

• NO2 levels in outer London were 4.8% lower than expected had the expansion not gone ahead
• Particulate matter 2.5 (PM2.5) exhaust emissions from cars and vans in outer London were estimated to be 31% lower
• The London-wide compliance rate for vehicles subject to Ulez standards after the first year of the expansion (as of September 2024) was 96.7%
• For people living near London's busiest roads, there was an estimated 80% reduction in 2023 in people exposed to illegal levels of pollution, increasing to 82% in outer London, compared without Ulez
• There were nearly 100,000 fewer non-compliant vehicles detected in London on an average day in September 2024 compared with June 2023.

The results have been checked by a group of independent air quality analysis experts.

London boroughs which opposed Sir Sadiq Khan's expansion of the zone saw the largest reductions in nitrogen oxides (NOx) in 2024.

The report found the level of decreases were 15.4% in Sutton, 15.3% in both Croydon and Merton, and 15.2% in both Bromley and Harrow. All opposed the expansion of ULEZ.

Reacting to the report, Sir Sadiq said: "With boroughs in outer London seeing some of the biggest reductions in harmful emissions and London's deprived communities also seeing greater benefits, this report shows why expanding Ulez London-wide was so important."

"Indeed, the air in outer London is now as good as the air in the rest of England," he said.

"When I first became mayor, King's College said it would take 193 years to bring our air within lawful limits.

"We have done it this year, 185 years early.

"Thanks to Ulez and our other policies, all Londoners are now breathing substantially cleaner air - but there is still more to do."

But Keith Prince, Assembly member and transport spokesman for the Conservatives said: "The mayor is supposedly comparing these results to a London where the Ulez scheme didn't happen, as though we can accurately measure such a thing.

"How he can say that Ulez is responsible for London's air clearing up with a straight face is beyond me - the data relies on maybes, possibilities, assumptions, and straight up fantasy in order to justify a project that is saddling TfL (Transport for London) and Londoners with mountains of debt."

In September 2023, the mayor said Ulez expansion would help tackle climate change.

But the City Hall report found that when looking at London as a whole, carbon dioxide (CO2) emissions from cars and vans were only 1% lower than they would have been without the London-wide Ulez expansion.

That equates to a CO2 emission saving of 35,000 tonnes across London in 2024.

Since 2019, CO2 emissions are estimated to be 813,000 tonnes lower across London, equivalent to a 2% reduction.

The issue of Ulez expansion was a key issue during the 2024 mayoral election with the Conservative candidate Susan Hall saying she would scrap it.

In the Uxbridge by-election in 2023, the then Labour candidate (and now Uxbridge MP) Danny Beales blamed the expansion for his loss to the Conservative candidate who said they would oppose it.

Four London authorities, Bexley, Bromley, Harrow, Hillingdon, and Surrey County Council also took a legal challenge to the High Court in July but lost.

Reacting to the latest report, Colin Smith, leader of Bromley Council, criticised the "one size fits all lunacy" of Ulez expansion.

He said it had "destroyed care networks", forced people to change jobs, and created a "huge financial expense for people and businesses having to buy new vehicles they didn't want or need".

Simon Birkett, founder and director of Clean Air in London said the report showed the scheme had worked and that in combination with "cleaner" buses and taxis, Ulez had helped London slash NO2 concentrations by two thirds near busy roads and had edged the city closer towards World Health Organisation guidelines.

Rosamund Adoo-Kissi-Debrah whose daughter Ella died after air pollution made a material contribution to her death, said she was delighted.

"My daughter Ella died from emissions from the South Circular Road close to where we live, and I will not stop until everyone in London can breathe safe, clean air, regardless of where they live in the city."

Professor Tony Travers from the London School of Economics said Ulez had become a way of attacking the mayor, especially in the run-up to last year's mayoral election.

"Opposition (to Ulez) was greater in some parts of the media than across the population more generally. With the election long over and the policy implemented, his opponents have moved on," he said.

"Crime (or perceptions of it) is more likely to be used by his opponents now as their issue of choice."

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