TRUE data exposes threat of delaying Brussels LEZ
The proposed postponement of the LEZ tightening in 2025 would allow the highest emitters to remain on the road for two more years.
The Brussels low-emission zone (LEZ) is currently in the hot seat and its future is uncertain. Since elections in June, the government of the Brussels-Capital Region has yet to be formed, leaving an opening for political debate surrounding the LEZ and its implementation. Several parties have recently proposed a postponement of the planned LEZ tightening in 2025 to the Brussels Parliament, which would ultimately weaken the city’s commitment to improving the Belgian capital’s air quality.
In 2021, the TRUE Initiative, in partnership with Brussels Environment, investigated the potential impacts of the capital’s low-emission zone, already in effect since 2018, through a real-world remote sensing campaign. As one of the most polluted cities in Europe related to its nitrogen dioxide concentration levels, it’s estimated that air pollution causes more than 900 premature deaths annually in the region. The Brussels LEZ, therefore, was set to significantly improve air quality by progressively tightening its stringency to make Brussels diesel-free by 2030 and gasoline-free by 2035. The next phase prohibiting Euro 5 diesel and Euro 2 gasoline cars is now in danger of being delayed by two years to 2027.
The previous TRUE study, using 250,000 real-world emissions measurements from vehicles on the road, points to Euro 5 diesel cars as the light-duty vehicle class responsible for the largest share of nitrogen oxide (NOX) emissions – equalling 40% of total emissions from passenger cars and nearly 50% of emissions from light commercial vehicles, including taxis. Euro 6 diesel vehicles, which would still be allowed in the LEZ during this next phase, have NOX emissions around half of those from Euro 5 diesel vehicles in real driving conditions. This highlights the large potential emission benefits the next phase could generate.
While politicians are divided over the 2025 step, it’s clear the Brussels LEZ has proved extremely effective in improving air quality and reducing vehicle pollution. A 2022 study conducted by Brussels Environment showed that the LEZ contributed to notable reductions in NOX (31%), black carbon (62%), and particulate matter 2.5 (30%) emissions throughout the four years since its introduction in 2018.
This downward trend could continue if the Brussels LEZ remains on track. Advocates for clean air in the capital region, including doctors and environmentalists, look to London, another TRUE city, and their Ultra Low Emission Zone (ULEZ) as a prime example. Covering all 32 boroughs of Greater London, the ULEZ currently allows only diesel cars and vans of Euro 6 and above, and gasoline cars and vans of Euro 4 and above, to enter. After only six months, the ULEZ has brought about a dramatic reduction in nitrogen dioxide (NO2) concentrations in central London, which was estimated to be 53% lower than they would have been without the ULEZ.
Although the Brussels LEZ scheme is less strict than London, its impact will still be substantial. A recent memo from Brussels Environment in support of the 2025 schedule estimated that a two-year delay would result in NO2 levels exceeding the proposed EU average annual limit of 20 µg/m³ on 8% of all roads in Brussels in 2030. In addition, the excess carbon dioxide emissions caused by not adhering to the schedule could further cost the region €19 million in fines by 2030 and derail the Brussels-Capital Region from the European Commission’s targets of reducing greenhouse gas emissions by 47% by 2030.
With its progressive agenda for environmental and health policies, Brussels was on track to showcase how an LEZ could succeed in improving air quality and its health impacts if supplemented by policies to support those that are most vulnerable to the impacts. A delay of its next phase will be a giant step back that would result in negative environmental, social, and financial consequences.
