1

By its application, the European Commission asks the Court of Justice to declare that:

2

Recitals 2, 17 and 18 of Directive 2008/50 state:

…

3

Headed ‘Subject matter’, Article 1 of Directive 2008/50 states, in points 1 to 3:

‘This Directive lays down measures aimed at the following:

4

Headed ‘Definitions’, Article 2 of that directive provides, in points 5, 7, 8, 16, 18 and 24:

‘For the purposes of this Directive:

…

…

…

…

…

5

Headed ‘Limit values and alert thresholds for the protection of human health’, Article 13 of Directive 2008/50 provides, in paragraph 1:

‘Member States shall ensure that, throughout their zones and agglomerations, levels of sulphur dioxide, PM10, lead, and carbon monoxide in ambient air do not exceed the limit values laid down in Annex XI.

In respect of nitrogen dioxide and benzene, the limit values specified in Annex XI may not be exceeded from the dates specified therein.

Compliance with these requirements shall be assessed in accordance with Annex III.

The margins of tolerance laid down in Annex XI shall apply in accordance with Article 22(3) and Article 23(1).’

6

Headed ‘Air quality plans’, Article 23 of Directive 2008/50 states, in paragraph 1:

‘Where, in given zones or agglomerations, the levels of pollutants in ambient air exceed any limit value or target value, plus any relevant margin of tolerance in each case, Member States shall ensure that air quality plans are established for those zones and agglomerations in order to achieve the related limit value or target value specified in Annexes XI and XIV.

In the event of exceedances of those limit values for which the attainment deadline is already expired, the air quality plans shall set out appropriate measures, so that the exceedance period can be kept as short as possible. The air quality plans may additionally include specific measures aiming at the protection of sensitive population groups, including children.

Those air quality plans shall incorporate at least the information listed in Section A of Annex XV and may include measures pursuant to Article 24. Those plans shall be communicated to the Commission without delay, but no later than two years after the end of the year the first exceedance was observed.

Where air quality plans must be prepared or implemented in respect of several pollutants, Member States shall, where appropriate, prepare and implement integrated air quality plans covering all pollutants concerned.’

7

Article 27 of Directive 2008/50 contains obligations concerning the submission of annual air quality reports by the national authorities. It provides that Member States must transmit to the Commission information on ambient air quality no later than nine months after the end of each year, including on zones and agglomerations in which the levels of one or more pollutants are higher than the limit values laid down in that directive, plus any margin of tolerance.

8

Annex XI to that directive, entitled ‘Limit values for the protection of human health’, sets, in Section B, the following limit values for ΝΟ2:

‘…

…

Nitrogen dioxide

…’

9

Annex XV to that directive lists the information to be included in the local, regional or national air quality plans for improvement in ambient air quality. Under point 8 of Section A of that annex, details are required of the measures or projects adopted with a view to reducing pollution, including the listing and description of all the measures set out in the project concerned, the timetable for the implementation of those measures and the estimate of the improvement of air quality planned and of the expected time required to attain those objectives.

10

On 28 May 2015, the Commission sent a letter of formal notice to the Portuguese Republic concerning the failure to comply with the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 in the zones of Lisboa Norte (PT‑3001), Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), formerly the zone of Braga (PT‑1001). In that letter of formal notice, the Commission stated that the persistent and systematic failure to comply with the annual limit value laid down by Directive 2008/50 constituted an infringement of the obligation laid down in Article 13(1) of that directive, read in conjunction with Section B of Annex XI thereto, which lays down the obligation not to exceed that limit value. In addition, the Commission pointed out that the Portuguese Republic had also failed to comply with the obligation laid down in Article 23(1) of that directive, read individually and in conjunction with Section A of Annex XV thereto, which requires Member States to take appropriate measures so that the period of exceedance of the annual limit value for the pollutant concerned can be kept as short as possible.

11

By letters of 17 July 2015, 16 October 2015 and 20 September 2017, the Portuguese Republic replied to that letter of formal notice. In those letters, the Portuguese Republic referred to a number of measures adopted and in the process of being adopted in each of the zones concerned in order to bring to an end the exceedance of the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50.

12

The Commission continued to monitor developments in the situation and, following the analysis of the various replies to the same letter of formal notice, as well as the assessment of the annual air quality reports submitted by the Portuguese authorities in accordance with Article 27 of Directive 2008/50, it concluded that the failure to fulfil obligations persisted.

13

In that context, on 13 February 2020, the Commission sent the Portuguese Republic a reasoned opinion concerning its failure to fulfil its obligations under Directive 2008/50. In that opinion, the Commission concluded that, by failing to ensure compliance with the annual limit value for ΝΟ2 in ambient air laid down by that directive from the year 2010 up to and including the year 2018 in the zones concerned, the Portuguese Republic had persistently and systematically infringed Article 13 of that directive, read in conjunction with Annex XI thereto. Furthermore, the Commission found that, by failing to take appropriate and sufficient measures to ensure compliance with the annual limit value for ΝΟ2 in ambient air so that the period of exceedance of that limit value for the pollutant concerned was kept as short as possible in those zones, the Portuguese Republic had failed, as regards the latter, to fulfil its obligations under Article 23(1) of that directive, read individually and in conjunction with Section A of Annex XV thereto, and, in particular, the obligation to ensure that that period of exceedance was kept as short as possible.

14

The period prescribed by the Commission for the Portuguese Republic to take the measures necessary to comply with the reasoned opinion was initially set at two months from the date of receipt of that opinion. However, in view of the exceptional circumstances linked to the COVID-19 pandemic, all ongoing time limits in infringement proceedings were extended. The deadline for that Member State to reply to that opinion was therefore postponed until 15 June 2020.

15

The Portuguese Republic replied to that opinion by letter of 24 June 2020. In that letter, that Member State did not dispute the failure to comply with the annual limit value concerned, but repeated and supplemented the information provided in its replies to the letter of formal notice.

16

On 25 March 2022, after examining that additional information, the Commission found that the Portuguese Republic had failed to fulfil its obligations under Directive 2008/50 and brought an action for failure to fulfil obligations under Article 258 TFEU.

17

By its first complaint, the Commission claims that, by systematically and persistently exceeding the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 from 1 January 2010 in the zones of Lisboa Norte (PT‑3001), Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), the Portuguese Republic has failed to fulfil its obligations under Article 13(1) of that directive, read in conjunction with Section B of Annex XI thereto.

18

As a preliminary point, the Commission notes that, according to settled case-law, the fact of exceeding the limit values for pollutants in ambient air is sufficient in itself to establish an infringement of the combined provisions of Article 13(1) of, and Annex XI to, Directive 2008/50. The Commission refers in particular to the judgment of 3 June 2021, Commission v Germany(Limit values – ΝΟ2) (C‑635/18, EU:C:2021:437, paragraph 78).

19

The Commission also recalls that the existence of an infringement is assessed in the light of the situation of the Member State as it stood at the end of the period laid down in the reasoned opinion, namely, in this case, 15 June 2020.

20

In the present case, the annual reports on air quality submitted by the Portuguese Republic demonstrated that the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 had been systematically and persistently exceeded from 2010 in the zones of Lisboa Norte (PT‑3001), Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009). In addition, there is no coherent downward trend in ΝΟ2 concentrations in ambient air in those three zones.

21

As regards the zone of Lisboa Norte (PT‑3001), the annual values of ΝΟ2 concentrations in ambient air, measured in μg/m3, were the following, namely 65 in 2010, 61 in 2011, 58 in 2012, 53 in 2013, 53 in 2014, 59 in 2015, 57 in 2016, 60 in 2017, 61 in 2018, 55 in 2019 and 40 in 2020. Thus, exceedances of the annual limit value set for ΝΟ2 in ambient air by Directive 2008/50 were allegedly observed every year from 2010 to 2019, with an upward trend in ΝΟ2 concentrations in ambient air from 2016 to 2018. The level reached by them in 2019, namely 55 μg/m3, was 37% higher than that annual limit value. That annual limit value was complied with only in 2020.

22

As regards the zone of Porto Litoral (PT‑1004), the annual values of ΝΟ2 concentrations in ambient air, measured in μg/m3, were the following, namely 51 in 2010, 48 in 2011, 47 in 2012, less than 40 in 2013, 47 in 2014, 65 in 2015, 75 in 2016, 54 in 2017, 62 in 2018, 48 in 2019 and 40 in 2020. Thus, exceedances of the annual limit value set for ΝΟ2 in ambient air by Directive 2008/50 were allegedly observed every year, except in 2013 and 2020, with ΝΟ2 concentrations in ambient air increasing sharply from 2014 to 2016 before decreasing in 2017, increasing again in 2018 and, finally, decreasing slightly in 2019. The level reached in 2019, namely 48 μg/m3, is 20% higher than that annual limit value.

23

As regards the zone of Entre Douro e Minho (PT‑1009), the annual values of ΝΟ2 concentrations in ambient air, measured in μg/m3, were the following, namely 48 in 2010, less than 40 in 2011 and in 2012, 50 in 2013, 44 in 2014, 46 in 2015, 55 in 2016, 55 in 2017, 50 in 2018, 57 in 2019 and 32 in 2020. Thus, exceedances of the annual limit value for ΝΟ2 in ambient air set by Directive 2008/50 were allegedly observed in 2010, as well as from 2013 to 2019. The recorded concentrations of ΝΟ2 in ambient air decreased slightly between 2013 and 2014 before increasing between 2016 and 2017, decreasing slightly in 2018 and, finally, further increasing in 2019, reaching a level of 57 μg/m3, which is 42% higher than that annual limit value.

24

As regards the data relating to 2020, the Commission notes that they were strongly influenced by the restrictions linked to the COVID-19 pandemic, which were implemented in the spring of 2020, and should therefore be assessed in the light of that very specific context. The Commission refers to several scientific studies which corroborate the causal link between (i) those restrictions and their impact on road traffic and (ii) the considerable decrease in levels of ΝΟ2 concentrations in ambient air. The Commission concludes that that decrease is unlikely to persist in time after the lifting of those restrictions. The fact that the Portuguese Republic stated that it complied with the annual limit value laid down for ΝΟ2 in Directive 2008/50 in 2020 therefore in no way supports the conclusion that the systematic and persistent exceedance previously established was brought to an end.

25

As regards, more specifically, the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), the Commission further states that, for the year 2020, the Portuguese Republic had not provided any data concerning the sampling points where exceedances of the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 had been recorded in the preceding years, namely the João Gomes Laranjo-S. Hora sampling point (PT 01030) and the Fr Bartolomeu Mártires-S. Vítor sampling point (PT 01041), respectively.

26

The Commission observes that, in order to conclude that a limit value laid down in Annex XI to Directive 2008/50 has been exceeded for the average calculated per calendar year, it is sufficient for a level of pollution in excess of that value to be measured at an isolated sampling point. The Commission refers, in that regard, to the judgment of 24 October 2019, Commission v France(Exceedance of limit values for nitrogen dioxide) (C‑636/18, EU:C:2019:900, paragraph 44). In this respect, the failure to communicate air quality data for a sampling point where exceedances have previously been found, without adequate justification being provided, would raise doubts about compliance with the annual limit value in the two zones in question.

27

Finally, the Commission notes that, in any event, the Portuguese Republic has not contested the failure to comply with the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 for the three zones concerned, so that that Member State has acknowledged the existence of an infringement in that regard.

28

In its defence, the Portuguese Republic submits that, for the zone of Lisboa Norte (PT‑3001), a persistent exceedance of the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 was found only at the air quality monitoring station on Avenida da Liberdade, which is situated in the centre of Lisbon (Portugal) in a densely built-up zone close to one of the main road traffic routes.

29

With regard to the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), while acknowledging that there is a continued situation of non-compliance with the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 up to and including the year 2019, the Portuguese Republic states that the absence of data in 2020 for the sampling points João Gomes Laranjo-S. Hora (PT 01030) and Fr Bartolomeu Mártires-S. Vítor (PT 01041) was due to functional problems with the ΝΟ2 analysers, which led to the invalidation of the measurements taken and the replacement of those analysers. Those problems were identified as early as 2017, but specific measures to resolve them could not be taken until 2021.

30

According to the Portuguese Republic, however, in view of the very particular context of the year 2020, during which the samples were affected by the containment measures linked to the COVID-19 pandemic, and despite the existence of a doubt as to compliance with the annual limit value laid down for ΝΟ2 in ambient air by Directive 2008/50 at those two sampling points, it is likely that that limit value was complied with.

31

Furthermore, the Portuguese Republic claims that the exceedances observed could be explained by the limited effectiveness of the EU legislation seeking to reduce exhaust gas emissions, revealed in the context of the case known as ‘dieselgate’ in 2015. The measures taken at EU level to improve that effectiveness have not yet produced the expected effects.

32

Finally, the Portuguese Republic notes that the COVID-19 pandemic also had the negative effect of increasing the use of private individual transport to the detriment of public transport, whereas the use of the public transport had tended to increase before the year 2020.

33

In its reply, the Commission points out that, as regards the zone of Lisboa Norte (PT‑3001), a persistent exceedance at an isolated sampling point is sufficient to establish non-compliance with the limit values laid down in Annex XI to Directive 2008/50. Consequently, even if an exceedance was observed only at the Avenida da Liberdade station, it is sufficient to demonstrate non-compliance with that annex for the zone of Lisboa Norte.

34

As regards the lack of data in 2020 for the João Gomes Laranjo-S. Hora (PT 01030) and Fr Bartolomeu Mártires-S. Vítor (PT 01041) sampling points, the Commission observes, in essence, that a Member State cannot release itself from the obligation to collect and communicate data meeting the requirements of Directive 2008/50 by invoking failures for which it is, moreover, solely responsible. There is nothing to support the Portuguese Republic’s claim that it is likely that the annual limit value was complied with in 2020 at the sampling points concerned, despite the absence of reliable data.

35

Furthermore, as regards the Portuguese Republic’s argument concerning the effect of the situation in the ‘dieselgate’ case on the achievement of the objectives of reducing ΝΟ2 levels in ambient air, the Commission recalls that the Court rejected similar arguments in the judgments of 24 October 2019, Commission v France(Exceedance of limit values for nitrogen dioxide) (C‑636/18, EU:C:2019:900, paragraph 48), and of 10 November 2020, Commission v Italy (Limit values – PM10) (C‑644/18, EU:C:2020:895, paragraph 88).

36

Finally, the Commission notes that the Portuguese Republic’s claim relating to the increased use of individual transport to the detriment of public transport in 2020 has not been proved and does not support the conclusion that ΝΟ2 emissions in ambient air in 2020 were abnormally high.

37

In its rejoinder, the Portuguese Republic responds to the Commission’s argument that that Member State failed to collect and transmit data relating to the PT 01030 and PT 01041 sampling points for 2020. The Portuguese Republic states that the replacement of the faulty analysers was specifically intended to ensure compliance with the data quality requirements laid down in Directive 2008/50 and that the call for tenders for the acquisition of the new analysers was not launched until June 2021 because of financial constraints. Those analysers have in the meantime been installed and are now operational.

38

Finally, in support of its claim concerning the increased use of individual transport to the detriment of public transport in 2020, the Portuguese Republic cites an impact assessment report drawn up by the Instituto da Mobilidade e dos Transportes (Institute for Mobility and Transport, Portugal). It states that its claim does not seek to justify any abnormal increase in ΝΟ2 emissions in ambient air for 2020, but rather to explain that the adoption of additional measures is necessary in order for the trend in favour of an increased usage of public transport, which prevailed before the COVID-19 pandemic, to resume.

39

Under the second subparagraph of Article 13(1) of Directive 2008/50, as regards ΝΟ2, the limit values laid down in Annex XI thereto may not be exceeded from the dates set out in that annex.

40

Section B of Annex XI to that directive provides that, on 1 January 2010, the limit value per calendar year for ΝΟ2 is set at 40 μg/m3.

41

In that regard, it should be recalled that the complaint alleging infringement of Article 13 of that directive must be assessed taking into account the settled case-law of the Court, according to which the procedure provided for in Article 258 TFEU presupposes an objective finding that a Member State has failed to fulfil its obligations under the FEU Treaty or secondary legislation (judgment of 16 February 2023, Commission v Greece(Limit values – ΝO2), C‑633/21, EU:C:2023:112, paragraph 34 and the case-law cited).

42

According to settled case-law, the fact of exceeding the limit values fixed by Directive 2008/50 for pollutants in ambient air is in itself sufficient for a finding of a failure to comply with Article 13(1) of, in conjunction with Annex XI to, that directive (judgment of 16 February 2023, Commission v Greece(Limit values – ΝΟ2), C‑633/21, EU:C:2023:112, paragraph 35 and the case-law cited).

43

The infringement of those provisions is examined in that context at the level of zones and agglomerations, and the exceedance concerned must be analysed for each zone or agglomeration on the basis of the records taken by each monitoring station. In order to establish that a limit value laid down in Annex XI to that directive has been exceeded in respect of the average calculated for a calendar year, it is sufficient for a level of pollution in excess of that limit value to be measured at an isolated sampling point. Consequently, there is no de minimis threshold for the number of zones in which an exceedance can be observed (see, to that effect, judgment of 3 June 2021, Commission v Germany(Limit values – ΝΟ2), C‑635/18, EU:C:2021:437, paragraphs 86 and 87 and the case-law cited).

44

In those circumstances, it cannot be sufficient, in order to prevent a finding of a systematic and persistent failure to comply with the provisions of Article 13 of, in conjunction with Annex XI to, Directive 2008/50, that the limit values referred to therein were not exceeded for certain years during the period covered by the action. Indeed, as is apparent from the very definition of ‘limit value’ in Article 2(5) of Directive 2008/50, that value must, in order to avoid, prevent or reduce harmful effects on human health and/or the environment as a whole, be attained within a given time limit and not be exceeded once attained (judgment of 10 November 2020, Commission v Italy (Limit values – PM10), C‑644/18, EU:C:2020:895, paragraph 75).

45

In the present case, it is apparent from the Commission’s arguments that its first complaint concerns the period from 1 January 2010 to the year 2020 inclusive, whereas the reasoned opinion of 13 February 2020, referred to in paragraph 13 of this judgment, related only to the period from 2010 to 2018 inclusive.

46

In that context, it should be recalled that, while the subject matter of an action for failure to fulfil obligations under Article 258 TFEU is determined by the Commission’s reasoned opinion, so that the action must be based on the same grounds and pleas in law as that opinion, the Court has held that where, as in the present case, such an action seeks a finding of a systematic and persistent failure to comply with the combined provisions of Article 13(1) of, and Annex XI to, Directive 2008/50, the production of additional evidence intended, at the stage of the proceedings before the Court, to substantiate the generality and consistency of the failure thus alleged cannot be excluded in principle. Thus, the subject matter of an action for failure to fulfil obligations which is alleged to be persistent may extend to facts subsequent to the reasoned opinion, provided that those facts are of the same nature and constitute the same conduct as the facts referred to in that opinion (see, to that effect, judgment of 3 June 2021, Commission v Germany(Limit values – ΝΟ2), C‑635/18, EU:C:2021:437, paragraphs 47, 54 and 55 and the case-law cited).

47

As regards the infringement alleged in the present case, it must be held that the data relating to the years 2019 and 2020 constitute facts which occurred after the reasoned opinion of 13 February 2020, but which are of the same nature as those referred to in that reasoned opinion and constitute the same conduct, so that the subject matter of the action may extend to them (see, by analogy, judgment of 3 June 2021, Commission v Germany(Limit values – ΝΟ2), C‑635/18, EU:C:2021:437, paragraph 57 and the case-law cited).

48

In that regard, it is apparent from the data cited in paragraphs 20 to 23 of the present judgment that the ΝΟ2 concentrations in ambient air in the three zones in question considerably and regularly exceeded the annual limit value of 40 μg/m3 between 1 January 2010 and the year 2019 inclusive. It should be recalled that those data were communicated by the Portuguese authorities themselves and are therefore not disputed.

49

As regards the zone of Lisboa Norte (PT‑3001), the annual limit value for ΝΟ2 in ambient air set by Directive 2008/50 was never complied with during that period. In other words, the exceedance of that annual limit value was permanent from 2010 to 2019. For the zone of Porto Litoral (PT‑1004), that annual limit value was complied with, during that period, only in 2013 and in 2020. In other words, that exceedance persisted from 2010 to 2012 and from 2014 to 2019. Finally, as regards the zone of Entre Douro e Minho (PT‑1009), the same annual limit value was complied with, during the same period, only in 2011 and in 2012. In other words, that exceedance was observed in 2010 and was uninterrupted from 2013 to 2019.

50

It follows that, having regard to the case-law cited in paragraph 44 of this judgment, for the period from 1 January 2010 to the year 2019 inclusive, the exceedances found must be regarded as persistent and systematic, without the Commission being required to adduce further evidence in that regard (see, by analogy, judgment of 3 June 2021, Commission v Germany(Limit values – ΝΟ2), C‑635/18, EU:C:2021:437, paragraph 82 and the case-law cited).

51

The fact that the annual limit value set for ΝΟ2 in ambient air by Directive 2008/50 was complied with in those zones in 2020 in an isolated manner does not mean that those persistent and systematic exceedances ended during that year.

52

As regards, in the first place, the zone of Lisboa Norte (PT‑3001), the Portuguese Republic claims that the exceedance is limited to a single sampling point. In the light of the case-law referred to in paragraph 43 of the present judgment, it is sufficient for a pollution level higher than the limit value concerned to be measured at an isolated sampling point for a failure to fulfil the obligations under Directive 2008/50 to be established. The fact that that sampling point is located in a place characterised by a high construction and road traffic density is irrelevant in that regard.

53

In the second place, as regards the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), while the data submitted by the Portuguese authorities did not report exceedances in 2020, it should be noted that, as the Portuguese Republic has acknowledged, it was an atypical year, characterised by the impact of the containment measures linked to the COVID-19 pandemic, so that the observed fall in ΝΟ2 concentration levels in ambient air was of a cyclical nature, and that, having regard to the case-law of the Court referred to in paragraph 44 of this judgment, it is not sufficient, in order to prevent a finding of a systematic and persistent failure to comply with the combined provisions of Article 13 of Directive 2008/50 and Annex XI thereto, for the limit values referred to therein not to have been exceeded in the course of such an atypical year.

54

Moreover, those data do not include, for the year 2020, any results concerning two sampling points where exceedances of that limit value were recorded in previous years, owing to functional problems affecting the ΝΟ2 analysers in those zones. In such a context, since the Portuguese Republic has acknowledged that those problems had already been identified in 2017, without measures having been taken in sufficient time to resolve them, there is nothing to support its claim that it is likely that the annual limit value was complied with at those two sampling points in 2020.

55

Finally, with regard to the Portuguese Republic’s argument concerning the alleged ineffectiveness of the EU legislation on the reduction of exhaust gas emissions, which was revealed in the context of the ‘dieselgate’ case in 2015, it should be recalled that, according to the settled case-law of the Court, the EU rules applicable to the type-approval of motor vehicles cannot exempt Member States from their obligation to comply with the limit values laid down by Directive 2008/50 on the basis of the scientific knowledge and the experience of the Member States in such a way as to reflect the level deemed appropriate by the European Union and by the Member States for the purpose of avoiding, preventing or reducing the harmful effects of air pollutants on human health and the environment as a whole (see, in particular, judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 106 and the case-law cited).

56

Consequently, the first complaint must be upheld.

57

By its second complaint, the Commission claims that the Portuguese Republic has failed to fulfil its obligations under Article 23(1) of Directive 2008/50, read individually and in conjunction with Section A of Annex XV thereto, so far as concerns the zones of Lisboa Norte (PT‑3001), Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), and, in particular, its obligation under the second subparagraph of Article 23(1) of that directive to take appropriate measures so that the period of exceedance of the limit values for the pollutant concerned is kept as short as possible.

58

The Commission points out that, under the second subparagraph of Article 23(1) of Directive 2008/50, Member States are required to adopt air quality plans in the event of exceedance of the limit values laid down in Annex XI to that directive. It also notes that, according to the case-law of the Court, although the Member States have some leeway in determining the measures to be adopted, those measures must, in any event, ensure that the period during which the limit values set for the pollutant concerned are exceeded is kept as short as possible. The Commission refers, in that regard, to the judgment of 3 June 2021, Commission v Germany(Limit values – ΝΟ2) (C‑635/18, EU:C:2021:437, paragraph 142).

59

According to the Commission, the Portuguese Republic was therefore required to adopt and to implement, as soon as possible, appropriate measures to that end. However, in view of the considerable systematic and persistent exceedances recorded during the period in question, the Portuguese Republic has clearly failed to fulfil that obligation.

60

As regards the zone of Lisboa Norte (PT‑3001), the air quality plan for the region of Lisboa e Vale do Tejo, approved in February 2019 and in force on the expiry of the period laid down in the reasoned opinion, namely 15 June 2020, does not meet the requirements of point 8(b) and (c) of Section A of Annex XV to Directive 2008/50.

61

According to the Commission, that plan, which included policies and measures to be implemented until 2020, focusing mainly on the transport sector, was based on data from 2014 and on an unrealistic modelling system, which had never been updated despite the increase in the levels of ΝΟ2 concentrations in ambient air observed after 2014. Moreover, that plan should have been followed by the approval of an implementation programme, which had not yet been approved by 15 June 2020. The Commission also notes that the same plan is unclear as to the specific content of some of the measures and the timetable for the implementation of those measures.

62

Furthermore, in addition to the shortcomings of the air quality plan for the region of Lisboa e Vale do Tejo as such, the Commission refers to failures to fulfil obligations as regards the actual implementation of the measures provided for in the plan. The Commission notes that, according to the case-law of the Court, where limit values are exceeded, such a situation should lead the Member State concerned as soon as possible not only to adopt but also to implement appropriate measures in an air quality plan, the room for manoeuvre available to that Member State in the event of those limit values being exceeded therefore being limited in that context by that requirement. The Commission refers, in that regard, to the judgment of 10 November 2020, Commission v Italy(Limit values – PM10) (C‑644/18, EU:C:2020:895, paragraph 150).

63

In the present case, the Portuguese Republic has failed to fulfil its obligations in so far as, even where that plan laid down a precise deadline for the implementation of a measure, that time limit was not complied with in many cases. The Commission thus refers to several examples of measures which have not been implemented or which have been only partially implemented.

64

Thus, as regards the measures which were allegedly not implemented, the Commission cites, inter alia, the case of measure E 2 (Regulation on the circulation of vehicles used for tourist activities in the city of Lisbon), which provided for a period of 180 days for the adoption of a municipal implementing regulation. That municipal regulation had still not been adopted by 15 June 2020. The Commission also cites the case of measure E 3.5 (bus lanes), which provided for the creation of an additional 8 kilometres (km) of lanes reserved for public transport and which was not implemented. The Commission also refers to the lack of effective implementation of measures P 1 (Reinforcement of the requirement linked to the low emission zone – LEZ – of the city of Lisbon) and E 1 (Reinforcement of the monitoring linked to the LEZ of the city of Lisbon), which the Portuguese authorities themselves have acknowledged to be essential in order to guarantee compliance with the ΝΟ2 limit values. As regards the measures partially implemented, the Commission cites, inter alia, the case of measure E 3.3 (Extension of the cycle network), which provided for an extension of the cycle network from 60 km to 200 km, and which was implemented only to a very limited extent (106 km in 2020).

65

As regards the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), the Commission observes that the last air quality plan for the Norte region, approved in June 2014 and accompanied by an implementation programme approved in September 2015, covered the period from 2015 to 2017 and has not been in force since 2018. The abovementioned zones are therefore currently not covered by any air quality plan. Such a situation inherently constitutes an infringement of Article 23(1) of Directive 2008/50.

66

Furthermore, the air quality plan for the period from 2015 to 2017, as implemented by the Portuguese authorities, did not comply with the requirements of Article 23(1) of that directive, read in conjunction with point 8 of Section A of Annex XV thereto.

67

First, the measures provided for in the plan were insufficient, since, according to the estimates of the Portuguese authorities themselves, those measures could have resulted only in a reduction in the average annual ΝΟ2 concentrations in ambient air of around 4 μg/m3 to 5 μg/m3. Given the exceedances recorded in the zones concerned, such a reduction would not have been sufficient to comply with the annual limit value set for ΝΟ2 in ambient air by Directive 2008/50. Furthermore, according to the Commission, several of the measures envisaged are generic and have not been rigorously quantified in terms of their expected impact. The Commission mentions the case of measure M 3 (carpooling), the content of which has not been precisely explained and the impact of which has not been quantified. One of the actions allegedly carried out under that measure was a simple awareness-raising campaign, carried out by means of a single publication on the social network Facebook.

68

Secondly, those measures were not properly implemented. According to the Commission, the Portuguese Republic acknowledged that the measures had been implemented only partially, that is, at a level of 59%. The Commission refers to many measures that have not been implemented or the implementation of which has been significantly delayed.

69

Thus, with regard to the measures which were not implemented, the Commission refers, in particular, to the example of measure M 8 (Low Emission Zone) which was to cover part of Matosinhos, Leça da Palmeira, Senhora da Hora and S. Mameda De Infesta and which had not been implemented in any way by 15 June 2020. As regards the measures the implementation of which was significantly delayed, the Commission cites, inter alia, measure M 2 (Improvement of the public transport network), in respect of which the Portuguese Republic has not, moreover, provided any details as to either the specific objectives pursued or the results achieved.

70

In the alternative, the Commission submits an analysis of other measures which, without constituting air quality plans within the meaning of Article 23(1) of Directive 2008/50, were nevertheless submitted by the Portuguese Republic as measures contributing to the reduction of ΝΟ2 concentrations in ambient air.

71

The Commission notes that the measures referred to are national in scope and are therefore not intended specifically to reduce ΝΟ2 concentrations in the areas concerned by the present action for failure to fulfil obligations.

72

As regards the Estratégia Nacional do Ar 2020 (National Air Strategy 2020; ‘the ENAR 2020’), the Commission submits that it constitutes a generic list of measures which cannot be implemented directly and which, moreover, do not include a deadline for implementation. Furthermore, the ENAR 2020 has not been revised since its adoption in 2016 and, if it were to lead to the adoption of more ambitious air quality plans for the zones in question, they would in any event be out of time, given the exceedances of the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 which have been persistently observed since 2010.

73

Lastly, as regards the programmes financed through the Fundo Ambiental (Environment Fund, Portugal), namely a programme to support the reduction of public transport fares, a programme to encourage the purchase of low-emission vehicles and a programme to support electric mobility in public administrations, the Commission observes that the scope of those programmes has not been quantified and that they do not constitute support measures. According to the Commission, the same is true of the economic and social stabilisation programme adopted in June 2020, which seeks to promote teleworking, without quantifying its impact, and of the national campaign ‘Por um pais com bom ar’ (For a country with cleaner air), intended to educate and make citizens and businesses aware of good environmental practices.

74

In its defence, the Portuguese Republic contests the existence of a failure to fulfil the obligation laid down in Article 23(1) of Directive 2008/50. In particular, it maintains that various measures have been implemented, both in the zones concerned and at national level. It further states that the alleged infringements concern very densely populated areas, with ΝΟ2 emissions in ambient air linked to road traffic and mobility habits.

75

As regards the zone of Lisboa Norte (PT‑3001), the Portuguese Republic states that the air quality plan for the region of Lisboa e Vale do Tejo provides for various measures, grouped into eight types of policy, structured according to two scenarios, namely, respectively, a ‘baseline scenario’ including measures in the course of implementation until 2023 and an ‘envisaged scenario’ including measures which could be added to those in the baseline scenario and which have not yet been approved.

76

According to the Portuguese Republic, the fact that the programme for implementing the measures was not approved does not prevent some of them from already being applied.

77

In that context, the Portuguese Republic notes that the measures in the baseline scenario could lead to a 19% reduction in ΝΟ2 emissions in ambient air for the whole city of Lisbon. By adding the measures of the envisaged scenario, it would be possible to reduce those emissions by approximately 23% for that city as a whole. The most significant measure is that linked to the renewal of the fleet of the public transport company Carris. The Portuguese Republic considers that, if all those measures were implemented, it would be possible to comply with the annual limit value laid down for ΝΟ2 in ambient air by Directive 2008/50 in 2023.

78

As regards the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), the Portuguese Republic acknowledges that there is currently no new air quality plan for them. That Member State also acknowledges that the air quality plan for the period from 2015 to 2017 did not have the expected impact in terms of reducing ΝΟ2 concentrations in ambient air.

79

However, the Portuguese Republic submits that the regional authorities seek to identify additional measures which could contribute to such a reduction and to coordinate with the local authorities of Porto, Matosinhos and Braga in order to assess their capacity to implement such measures. According to the Portuguese Republic, account should also be taken of the fact that the COVID-19 pandemic delayed the efforts made to reduce the exceedances observed.

80

In its reply, the Commission observes, in general terms, that the Portuguese Republic does not rely on new evidence in support of its position.

81

With regard to the zone of Lisboa Norte (PT‑3001), the Commission submits that, having regard, in particular, to the fact that the authorities concerned have still not adopted a programme for the implementation of the air quality plan approved in 2019 and in view of the very slow pace of implementation observed so far, the measures taken and implemented by the Portuguese Republic do not make it possible to ensure that the period of exceedance of the limit values laid down for the pollutant concerned is kept as short as possible, with the result that a failure to fulfil obligations under Article 23(1) of Directive 2008/50 is established.

82

As regards the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), in view of the lack of air quality plans in force and in view of the very slow pace of implementation observed so far, the Commission also concludes that there has been a failure to fulfil obligations under that provision.

83

Finally, the Commission observes that the shortcomings of the measures adopted and implemented by the Portuguese Republic since 2010 to ensure that the period of exceedance of the limit values for the pollutant concerned is kept as short as possible cannot be justified by a pandemic which occurred in 2020.

84

In its rejoinder, as regards the zone of Lisboa Norte (PT‑3001), the Portuguese Republic reiterates its claim that the lack of formal approval of the implementation programme for the air quality plan did not have the effect of preventing the implementation of the measures envisaged under the baseline scenario. Some of those measures were carried out through the Environment Fund or local authority financing programmes.

85

That is true, in particular, of the measure aimed at renewing the bus fleet of the public transport company Carris, which could contribute to reducing ΝΟ2 emissions in ambient air within the city of Lisbon by 8% by 2023. Those measures, which are already in the process of being implemented, are intended to be supplemented by an additional measure, consisting of offering public transport tickets free of charge for persons under the age of 23 and over 65 years of age.

86

Finally, the Portuguese Republic refers to the initiatives undertaken under the ENAR 2020 and the Environment Fund at national level, such as the scheme to encourage the purchase of low-emission vehicles and support for electricity mobility within public administrations. Those initiatives, dating from 2017, benefit in particular the zones of Lisboa Norte (PT‑3001), Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009).

87

Pursuant to the first to third subparagraphs of Article 23(1) of Directive 2008/50, where, in given zones, the levels of pollutants in ambient air exceed any limit value, Member States are to ensure that air quality plans are established for those zones in order to achieve the related limit value specified in Annex XI to that directive. In the event of exceedances of those limit values for which the attainment deadline is already expired, those plans are to set out appropriate measures, so that the exceedance period can be kept as short as possible.

88

Those plans are to include at least the information listed in Section A of Annex XV to that directive. Under point 8 of Section A of that annex, information is required on the measures adopted with a view to reducing pollution, including the listing and description of all the measures set out in the project concerned, the timetable for the implementation of those measures, and an estimate of the improvement of air quality planned and of the expected time required to attain those objectives.

89

According to settled case-law, Article 23(1) of Directive 2008/50 has a general scope, given that it applies, without being limited in time, to breaches of any pollutant limit value established by that directive, after the deadline fixed for its application, whether that deadline is fixed by that directive or by the Commission under Article 22 of the directive (judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 152 and the case-law cited).

90

It must also be noted that Article 23 of Directive 2008/50 establishes a direct link between, first, the exceedance of the limit values for ΝΟ2, as laid down in the provisions of Article 13(1) of, in conjunction with Annex XI to, that directive, and, secondly, the drawing up of air quality plans (judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 153 and the case-law cited).

91

Those plans may be adopted only on the basis of the balance between the aim of minimising the risk of pollution and the various opposing public and private interests (judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 154 and the case-law cited).

92

Therefore, the fact that a Member State has exceeded the limit values for ΝΟ2 is not in itself sufficient to find that that Member State has failed to fulfil its obligations under the second subparagraph of Article 23(1) of Directive 2008/50 (judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 155 and the case-law cited).

93

However, it follows from the second subparagraph of Article 23(1) of Directive 2008/50 that, while Member States have a degree of discretion in deciding which measures to adopt, those measures must, in any event, ensure that the period during which the limit values set for the pollutant concerned are exceeded is kept as short as possible (judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 156 and the case-law cited).

94

In those circumstances, it must be ascertained, on the basis of a case-by-case analysis, whether the plans drawn up by the Member State concerned comply with the second subparagraph of Article 23(1) of Directive 2008/50 (judgment of 12 May 2022, Commission v Italy (Limit values – ΝΟ2), C‑573/19, EU:C:2022:380, paragraph 157 and the case-law cited).

95

Such a case-by-case analysis must also address the question whether the measures adopted have indeed been implemented. According to the case-law, where it is established that the limit values have been exceeded, such a situation should lead the Member State concerned as soon as possible not only to adopt but also to implement appropriate measures in an air quality plan, the discretion available to that Member State in the event of an exceedance of the limit values being accordingly, in that context, limited by that requirement (see, to that effect, judgment of 10 November 2020, Commission v Italy (Limit values – PM10), C‑644/18, EU:C:2020:895, paragraph 150).

96

In the present case, as regards the zone of Lisboa Norte (PT‑3001), it appears that there were shortcomings in the air quality plan, in force on 15 June 2020, in so far as it was based on data from 2014 that had not been updated, and in so far as it contained gaps as regards the specific content of certain measures and the timetable for the implementation of those measures.

97

In addition, that plan was to be accompanied by an implementation programme which, as of 15 June 2020, had not been formally approved. Even though, as the Portuguese Republic submits, that lack of approval did not prevent the adoption of a series of measures, it is apparent from the information provided by the Commission, and not disputed by the Portuguese Republic, that the implementation of those measures was delayed and partial. Furthermore, it is apparent from the information provided by the Portuguese Republic that the adoption and implementation of all the measures envisaged could lead to compliance with the annual limit value for ΝΟ2 in ambient air set by Directive 2008/50 in 2023 at the earliest.

98

In any event, since the exceedance of the annual limit value for ΝΟ2 in ambient air laid down by Directive 2008/50 persisted from 2010 until 2020 inclusive, it must be held that the measures adopted and implemented by the Portuguese authorities clearly did not ensure that the period of exceedance of the limit values for the pollutant concerned was kept as short as possible, with the result that non-compliance with Article 23(1) of that directive, read individually and in conjunction with Section A of Annex XV to that directive, is established.

99

As regards the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009), it should be noted that the Portuguese Republic acknowledges the absence of any air quality plan since 2017. As the Commission has rightly pointed out, such a situation constitutes, in itself, a failure to fulfil obligations under Article 23(1) of Directive 2008/50, in view of the exceedances found in those zones.

100

As for the air quality plan for the period from 2015 to 2017, it must be held that the measures adopted were inherently insufficient, having regard to the estimates of the Portuguese authorities themselves. Furthermore, according to the information provided by the Commission and not contested by the Portuguese Republic, the implementation of the measures proved to be delayed and partial. The Portuguese Republic itself accepts that that plan did not have the expected impact in terms of reducing ΝΟ2 concentrations in ambient air and that, despite that observation, no new plan was adopted after 2017.

101

In that regard, the Portuguese Republic’s argument based on the impact of the COVID-19 pandemic on the adoption and implementation of appropriate measures cannot succeed. As the Commission has pointed out, the shortcomings of the measures which should have been adopted and implemented since 2010 to ensure that the period of exceedance of the limit values for the pollutant concerned is kept as short as possible cannot be justified by a pandemic which occurred in 2020.

102

Finally, the existence of initiatives taken at national level which could indirectly improve air quality within the zones concerned cannot remedy the shortcomings, let alone the absence, of air quality plans for those zones. It is clear from Article 23 of, and Annex XV to, Directive 2008/50 that the Member State concerned must establish an air quality plan, including appropriate measures, for each zone concerned. In those circumstances, the Portuguese Republic’s argument relating to the initiatives taken in the context of the ENAR 2020 strategy and the Environment Fund and their impact on ΝΟ2 concentrations in ambient air in those zones cannot succeed.

103

The failure to comply with the requirements of Article 23(1) of, and Annex XV to, Directive 2008/50 is therefore also established for the zones of Porto Litoral (PT‑1004) and Entre Douro e Minho (PT‑1009).

104

Consequently, the second complaint must be upheld.

105

In the light of all of the foregoing considerations, it must be held that:

106

Under Article 138(1) of the Rules of Procedure of the Court, the unsuccessful party is to be ordered to pay the costs if they have been applied for in the successful party’s pleadings. Since the Commission has applied for costs to be awarded against the Portuguese Republic and the latter has been unsuccessful, the Portuguese Republic must be ordered to pay the costs.

On those grounds, the Court (Sixth Chamber) hereby: