London hits legal NO2 limits for the first time since 2010 thanks to ULEZ expansion

London has achieved nitrogen dioxide (NO2) levels within legal limits for the first time since 2010, a milestone attributed to expanded Ultra Low Emission Zone (ULEZ) policies and cleaner transportation initiatives.

For the first time since the establishment of UK air quality regulations in 2010, London has achieved nitrogen dioxide (NO2) pollution levels within the legal limit, according to recent government data published by the Department for Environment, Food and Rural Affairs (Defra). This milestone marks a significant turnaround in the capital’s air quality amid longstanding concerns about harmful nitrogen dioxide emissions.

The successful reduction in toxic NO2 levels is widely attributed to the implementation and expansion of the Ultra Low Emission Zone (ULEZ) policies championed by London’s Mayor, Sir Sadiq Khan. Since its introduction, the ULEZ has steadily curbed roadside pollution, with data from multiple reports confirming its transformative impact. Following the 2023 expansion of the ULEZ to cover all London boroughs, a report revealed a 27% decrease in roadside NO2 levels citywide. This was accompanied by a notable 31% drop in particulate matter (PM2.5) emissions from vehicle exhausts in outer London compared to scenarios without the ULEZ expansion. Industry analysis equates these reductions to removing the equivalent of around 200,000 cars from the roads for a year.

The ULEZ initially covered central London in 2019 and was extended to inner London in 2021, resulting in a 46% reduction in NO2 levels in central areas and a 21% decrease across inner London by 2023. By 2024, estimates showed a 27% reduction in nitrogen dioxide levels across London and a dramatic 54% decrease in central London due to the ULEZ’s measures. Beyond NO2, the zone contributed to a 23% reduction in nitrogen oxides (NOx) emissions from cars and vans citywide since 2019. These improvements reflect the enforced charges on older, more polluting vehicles that incentivise cleaner alternatives, alongside increased adoption of electric vehicles and electrification of London’s bus fleet.

Despite this progress, not all UK cities have met the legal limits. Government data indicates that while London complied with the NO2 regulations in 2024, Manchester, Birmingham, and Liverpool exceeded those limits, underscoring the persistent air quality challenges in other urban areas.

Sir Sadiq Khan expressed his enthusiasm for the milestone, highlighting the significance of the ULEZ in improving public health and Londoners’ quality of life. Conservative representatives at City Hall have yet to comment on the achievement.

The improvements in London’s air quality come amid wider concerns over health impacts caused by nitrogen dioxide, a key pollutant linked to respiratory issues. The continued success of the ULEZ, together with complementary measures like expanding electric vehicle infrastructure, is viewed as a crucial blueprint for other cities striving to tackle pollution.

In summary, London’s attainment of legal NO2 levels is a landmark moment that reflects years of policy commitment and technological progress. The comprehensive data and reports reveal a clear causative link between emissions charges on polluting vehicles, expanded low emission zones, and tangible improvements in urban air quality, which bode well for the city’s environmental and public health future.

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Source: Noah Wire Services

Noah Fact Check Pro

The draft above was created using the information available at the time the story first
emerged. We’ve since applied our fact-checking process to the final narrative, based on the criteria listed
below. The results are intended to help you assess the credibility of the piece and highlight any areas that may
warrant further investigation.

Freshness check

Score:
10

Notes:
The narrative is based on a recent press release from the Mayor’s office, published on 30 September 2025, reporting that London met the legal limits for nitrogen dioxide (NO₂) pollution in 2024. ([london.gov.uk](https://www.london.gov.uk/london-meets-legal-limits-toxic-no2-pollution-first-time-almost-200-years-earlier-predicted?utm_source=openai)) This is the earliest known publication date for this information, indicating high freshness. The report highlights that London achieved this milestone almost 200 years earlier than predicted, demonstrating the effectiveness of the Ultra Low Emission Zone (ULEZ) policies.

Quotes check

Score:
10

Notes:
Direct quotes from the Mayor of London, Sadiq Khan, and other officials are included in the press release. These quotes are unique to this report and have not been found in earlier material, suggesting originality.

Source reliability

Score:
10

Notes:
The narrative originates from the Mayor’s office, a reputable source. The press release is published on the official London City Hall website, indicating high reliability.

Plausability check

Score:
10

Notes:
The claims about London’s air quality improvements are supported by recent data from the Department for Environment, Food and Rural Affairs (Defra), published on 30 September 2025. ([london.gov.uk](https://www.london.gov.uk/london-meets-legal-limits-toxic-no2-pollution-first-time-almost-200-years-earlier-predicted?utm_source=openai)) The report indicates that London met the Air Quality Standards regulations for the first time in 2024, with NO₂ levels nearly halved since 2016. The narrative aligns with previous reports on the effectiveness of ULEZ policies in reducing air pollution.

Overall assessment

Verdict (FAIL, OPEN, PASS): PASS

Confidence (LOW, MEDIUM, HIGH): HIGH

Summary:
The narrative is fresh, original, and originates from a reliable source. The claims about London’s air quality improvements are plausible and supported by recent data.