After imposing several penalty payments, the Conseil d'État has ruled that the French government has taken the necessary measures to improve air quality and has fully complied with its 2017 legal decision. No area now exceeds the pollution threshold for fine particulate matter (PM10), and the nitrogen dioxide (NO₂) threshold is nearly met in Lyon and close to being met in Paris.
In 2017, the Conseil d'État, acting on appeals from several environmental organisations, ordered the French government to implement plans to reduce concentrations of nitrogen dioxide (NO₂) and fine particulate matter (PM10) in 13 urban areas, with a view to meeting the pollution thresholds set by the European Air Quality Directive and incorporated into French law. In 2020, noting that the measures taken were still insufficient to achieve this goal in eight areas in France, it ordered the State to take action or face a fine of 10 million euros for every six months of delay.
In 2021 and 2022, the Conseil d'État ordered the French state to pay three 10-million-euro fines. In 2023, it ordered the government to pay two additional fines, reduced to 5 million euros for every six months of delay, noting that fine particulate pollution thresholds were no longer exceeded in any urban area, and nitrogen dioxide levels were only exceeded in Lyon and Paris.
Lyon: measures to comply with thresholds
In 2023 and 2024, air quality measuring stations in the Lyon metropolitan area met the threshold of 40 μg/m3 of nitrogen dioxide as an annual average. Only one measuring station recorded a concentration in excess of the threshold (measuring 44 μg/m3 in 2023), but it was expected to meet the 40 μg/m3 target in 2024.
The Conseil d'État ruled that, although the concentrations observed do not mean that the situation can be considered fully stabilised, the State has demonstrated that the measures taken will now ensure compliance with the thresholds in the Lyon conurbation. It noted that the third atmospheric protection plan for the conurbation, adopted on 24 November 2022, includes a range of specific measures to improve air quality, such as dedicated carpool lanes and speed limit regulations on certain roads, some of which had already been implemented in 2024. Furthermore, Lyon’s low-emission zone for transport (ZFE-m) is already helping to reduce transport-related air pollution and introduces new measures, including traffic restrictions for vehicles classified Crit'Air 3 and above, effective from 1 January 2025.
In view of all these factors, the Conseil d'État considered that its 2017 decision should be deemed implemented for the Lyon conurbation.
While occasional excesses persist in Paris, they are expected to be resolved promptly given the measures announced.
In the Paris urban area, the latest estimates for nitrogen dioxide indicate that three monitoring stations will still exceed the limit in 2024, two in 2025, and none by 2026.
While the maximum thresholds cannot yet be considered fully met, the Conseil d'État noted that specific measures have been implemented to continue reducing pollution in the remaining non-compliant areas. On one hand, the adoption of the Île-de-France region's fourth atmospheric protection plan in January 2025 introduced measures to improve air quality, including reducing the speed limit on certain roads. On the other hand, as of 1 January 2025, Crit'Air 3 vehicles and above are prohibited from entering the ZFE-m on weekdays between 8 a.m. and 8 p.m. Similar to the Lyon conurbation, the continuation of ongoing actions and the introduction of new measures should help reduce nitrogen dioxide emissions from vehicles, notably by promoting the ongoing renewal of the vehicle fleet.
In view of all the measures taken, the Conseil d'État considered that its 2017 decision should also be deemed as implemented for the Paris conurbation.
Air pollution trends in France since 2017 Fine particles: Nitrogen dioxide: |
Read the decision (in French)