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