Mayor Sadiq Khan’s Londonwide expansion of the ultra-low emission zone (Ulez) resulted in a “better than expected” reduction in toxic exhaust emissions from cars and vans, a City Hall report has suggested.
This helped to reduce the amount of nitrogen dioxide (NO2), a toxic gas, detected at the roadside in outer London by an estimated 2.7 per cent to 4.4 per cent – up to double that predicted.
As a result, about five million more Londoners are breathing cleaner air since Mr Khan chose to press ahead with the Ulez expansion – the world’s largest clean air zone - on August 29 last year.
However, the improvement in air quality is far less dramatic than seen after the launch of the central London Ulez in 2019 and the inner London Ulez in 2021. These cut NO2 concentrations by 46 per cent and 21 per cent respectively.
City Hall insists that “given the size of outer London, every percent makes a huge difference”.
The in-house analysis of the first six months of the Londonwide Ulez reveals:
- A 13 per cent reduction in nitrogen oxides (NOx) emissions from cars in outer London, surpassing the 10 per cent target.
- A seven per cent reduction in NOx emissions from vans, in line with predictions.
- A 22 per cent reduction in car exhaust emissions of PM2.5 particulates, better than expected.
- An increase in compliance rates from 93 per cent to 97.1 per cent for cars driving in the enlarged zone, and from 80.2 per cent to 88.9 per cent for vans. Vehicles that meet the Ulez emission standards are not liable for the £12.50-a-day charge.
Mr Khan said: “Today’s report shows that the Ulez is working even better than expected.
“The expansion to outer London is already having a significant effect – driving down levels of pollution, taking old polluting cars off our roads and bringing cleaner air to millions more Londoners.”
However, the City Hall Conservatives said the improvements were “minimal” when compared with the estimated £500m of public money spent expanding the zone.
Tory group leader Neil Garratt said: “The Conservative group were clear from the off that we absolutely supported improving air quality, but the case for the expansion simply did not add up. We can now see that reflected very clearly in the mayor’s own data.
“At the same time, we cannot forget there are many Londoners on low incomes who own non-compliant vehicles they purchased through finance. The scrappage scheme does not cover the amount they still owe on the vehicle, meaning they are trapped paying the £12.50 daily charge.”
According to the report, the combined reduction in NOx emissions is equivalent to removing 200,000 cars from the road for a year.
However, it admits that the improvement in air quality should be attributed to more than just the Ulez expansion.
Though thousands of Londoners will have got rid of non-compliant vehicles to avoid the 24/7 levy, many others will have upgraded to newer – and typically “greener” - cars regardless of the Ulez, including switching to electric cars.
Other factors include the increase in zero emission buses – about 1,500 of the capital’s 8,600-strong bus fleet is electric – an increase in cycling, and the phasing out of diesel taxis.
The 140-page report states: “It is not straightforward to isolate the impact of the Ulez and its expansions.
“Therefore the analysis… can be seen to show the impacts of not just the Ulez and its expansions, but of all the mayor’s policies to reduce emissions from transport.”
About two million vehicles a day are driven within Greater London. Of these, about 80,000 breach the Ulez emission rules.
Drivers who fail to pay the £12.50 levy receive an £180 fine. But about seven out of 10 drivers refuse to pay the fine – leaving Transport for London owed in excess of £200m, the Standard revealed in May.
Mr Khan spent about £160m expanding the zone from the inner boundary of the North and South Circular roads.
He also set aside a further £210m for a scrappage scheme, of which £183m has already been allocated – enabling 53,351 non-compliant vehicles to be removed from the street.
TfL has refused to reveal how much it has spent replacing or repairing more than 1,000 vandalised roadside cameras. There are more than 3,800 cameras across London.
In an updated version of his political memoir, Breathe, published last week, Mr Khan said that – despite fears that he faced the “fight of his life” to be re-elected mayor in May - expanding the Ulez was “not a political death wish”.
Prior to giving the go-ahead for the expansion, Mr Khan had been warned by TfL’s consultants Jacobs that the Ulez expansion was likely to have only a “moderate positive impact” on NOx emissions, a “minor positive impact” on PM emissions and a “minor positive impact” on the health of Londoners.
Thursday’s report suggests that London’s air quality is continuing to improve at a faster rate than the rest of England.
However, City Hall admits the report “does not provide the full analysis of the impacts of the scheme on air pollutant emissions and concentrations”.
Nor does it provide figures that would enable critics to establish whether the enlarged zone has cleaned up the air by as much as was originally promised in TfL’s 2022 consultation, in which a majority of respondents opposed the widening.
During the consultation, TfL estimated that, overall, widening the zone could “reduce road transport NOx emissions in outer London by 6.9 per cent, exhaust PM2.5 emissions in outer London by 13.6 per cent, and total road transport PM2.5 emissions in outer London by two per cent”.
Comparable data is due to be published next year in the “12 months on” report.
The report is also silent on what impact the expanded Ulez has had on carbon dioxide emissions – and whether it has helped move London towards the carbon “net zero” city that Mr Khan has promised by 2030. Carbon figures will also be provided in the “one year” report.
Professor Kevin Fenton, London’s director of public health, said the report “provides welcome and reassuring news that action to clean up London’s air is working”.
He said: “Roadside NO2 concentrations in outer London are 21 per cent lower than they would have been without all phases of the Ulez. These important reductions are likely to have significant benefits for the health and wellbeing of Londoners.”
Tim Dexter, from the charity Asthma + Lung UK, said: “These results are an incredible win in the fight to clean up London’s air. This is perfect proof that clean air schemes really do encourage people to adopt cleaner modes of transport.
“In the UK, up to 43,000 early deaths a year are linked to toxic air. With the success of Ulez so evident in London, we need to see similar bold action taken to clean up the air across the country.”
Hirra Khan Adeogun, co-director of climate charity Possible, said: “Sadiq Khan has shown real leadership here because without bold policies like the Ulez, it would have taken nearly two centuries for London to meet legal air pollution limits. We’re now on track to hit this milestone by 2025.”
Pre-pandemic, road transport accounted for 43 per cent of NOx emissions and 31 per cent of PM2.5 emissions in London.
Nitrogen oxides are nitric oxide and nitrogen dioxide (NO2), which are emitted by petrol and diesel vehicles. NO2 aggravates respiratory diseases – particularly asthma – and stunts the development of children’s lungs.
In London, the equivalent of about 4,000 premature deaths can be attributed to toxic air each year. Pollution also increases the risk of asthma and cancer. There is emerging evidence of links between air pollution and dementia.
