I Legal background

The Xylella fastidiosa case falls within the scope of Council Directive 2000/29/EC on protective measures against the introduction into the EU territory of organisms harmful to plants or plant products and against their spread within the Union (hereinafter “Plant Health Directive”).Footnote ¹

The Plant Health Directive, amended in November 2016,Footnote ² regulates the “introduction of plants and plant products into the EU from [third] countries, and the movement of plants and plant products within the EU”, and lists Xylella fastidiosa in Part A, Section I of Annex I, among the “harmful organisms not known to occur in any part of the EU and relevant for the entire EU”.

Article 16 of this Directive requires Member States “to immediately notify the Commission and the other Member States of the presence in its territory of any of the harmful organisms listed in Annex I, Part A, Section I […].” The Member State concerned “shall take all necessary measures to eradicate, or if that is impossible, inhibit the spread of the harmful organisms concerned. It shall inform the Commission and the other Member States of the measures taken.”Footnote ³

Moreover, according to Article 16(3), “in cases referred to in paragraphs 1 and 2, the Commission shall examine the situation as soon as possible within the Standing Committee on Plant Health. […] The necessary measures could be adopted, including those whereby it may be decided whether measures taken by the Member State should be rescinded or amended, under the procedure laid down in Article 19[…].” Before being amended, Article 23(2) of the Directive defined the necessary measures as “destruction, disinfection, disinfestation, sterilisation, cleaning or any other treatment carried out officially or upon official request” in respect of plants, plant products or other objects infected, liable to be infected, or used to introduce the harmful organism into the area in question.

In May 2015, two years after the presence of Xylella was detected for the first time in Apulia, the Commission adopted – among others – Decision 2015/789/EU,Footnote ⁴ implementing the Plant Health Directive. This decision contains a list of “specified plants” and provides for a buffer zone surrounding the infected zone (at least 10 km), stringent eradication measures, the introduction of containment measures, the establishment of a surveillance zone, and the creation of a system of traceability and official checks on movement of specified plants.

With regard to the eradication measures, Article 6(2) of Decision 2015/789 provides that the Member State concerned shall “immediately remove”: all infected plants, all host plants (regardless of their health), and all plants showing symptoms indicating possible infection by the bacterium or suspected to be infected by that bacterium, “within a radius of 100 metres around the plants which have been tested and found infected” by Xylella. In addition, under Article 6(3), Member States should, “within a radius of 100 metres around the plants which have been tested and found infected, sample and test the host plants, in accordance with the International Standard for Phytosanitary Measures”, while under Article 6(4), Member States should carry out “appropriate phytosanitary treatments prior to the removal of plants referred to in paragraph 2.” Such treatments should aim to eradicate the vectors of Xylella and their host plants, which may include the removal of plants.

II Facts

The pathogen Xylella fastidiosa is among the most dangerous plant bacteria worldwide, causing a variety of diseases with a huge economic impact on agriculture. The peculiarity of Xylella is that it lives in a plant’s xylem tissue, and is usually carried by spittlebugs, cicadas and sharpshooters, which feed on the xylem. By invading xylem vessels, Xylella blocks the transportation of water and soluble mineral nutrients, causing plants to wilt, dry up and die.

The pathogen’s presence has been limited to in America in the past, in particular in Costa Rica, Brazil and California, where it caused massive losses of grapevines in the 1990s. In 2013, the presence of Xylella was detected – for the first time in Europe – in southern Italy, where it rapidly infected thousands of olive trees in Apulia, the largest producer of olive oil in Italy.Footnote ⁵

A few months after the detection of Xylella, the infection became a phytosanitary emergency, requiring the EU to adopt emergency measures to eradicate the pathogen and stop the spread of the pest. The first measures put in place, such as limitations to the movement of plants and plant products within the EU, as well as pruning measures, were not sufficiently effective in eradicating the disease and containing its spread. As a consequence, on 30 December 2014, the Commission requested the scientific opinion of EFSA on “the risk to plant health posed by Xylella fastidiosa in the EU territory, with the identification and evaluation of risk reduction options”.Footnote ⁶

The opinion of EFSA – published on 6 January 2015 – showed that the causal link between Xylella and the disease affecting the olive trees in Apulia could not be confirmed with absolute scientific certainty. The report put forward that the disease might have been caused by a complex of pests, including Xylella, which the researchers named CoDiRo (Rapid Complex Desiccation of Olive Trees). This complex included “several fungal species belonging to the genera Phaeoacremonium and Phaemoniella and Zeuzera pyrina (leopard moth)”,Footnote ⁷ which could have been contributory causes of the disease, even if not the most significant.

However, EFSA pointed out that the association between the disease and Xylella was rated as very likely for so-called plants for planting because: “(1) they have been found to be a source of the bacterium for outbreaks; (2) host plants can be asymptomatic and often remain undetected; (3) a very large number of plant species are recorded as hosts; and (4) very high quantities of plants for planting are imported from countries where [Xylella] is reported.”Footnote ⁸ Therefore, according to EFSA, Xylella – whose presence in Europe at that moment was restricted to some tens of thousands of hectares in the province of LecceFootnote ⁹ – represented a major risk to the EU territory.Footnote ¹⁰ Indeed, Xylella had the potential to: (1) “cause disease in the risk assessment area once it establishes, as hosts are present and the environmental conditions are favourable”, and (2) infect not only olive trees, but also a much broader range of host plants, including citrus fruits, olives, grapes, almond, peach, oak, plane tree and oleander.Footnote ¹¹

Furthermore, EFSA was of the opinion that the complete elimination of Xylella from a focus zone was likely to be unsuccessful in the areas where the bacterium was extensively established. This was because the main obstacle to its complete eradication was represented by the wide range of host plants and various species of insects acting as vectors.Footnote ¹²

Following the EFSA assessment, the EU in 2015 laid down stricter measures, requiring Italy to eradicate all infected plants and all host plants, regardless of their health status, within a radius of 100 metres around the infected plants.

Nonetheless, such eradications were highly contested by local entrepreneurs and environmental associations, who challenged the Italian implementing measures before national administrative courts. In particular – in January 2016 – two of these casesFootnote ¹³ were referred by the Regional Administrative Court of Lazio to the CJEU for a preliminary ruling on the validity of the eradication measures laid down in Decision 2015/789 vis-à-vis the Plant Health Directive, and the principles of precaution and proportionality.Footnote ¹⁴

III Judgment

Firstly, regarding compatibility with the Plant Health Directive, the CJEU pointed out that the eradication measures laid down in Decision 2015/789 were based on Article 16(3) of the Directive, which requires the Commission to follow the development of the situation in case of actual or suspected presence of a harmful organism in a Member State, following notification by the latter. Moreover, the Directive requires – where certain conditions are metFootnote ¹⁵ – the Commission to “amend or repeal” the necessary measures adopted in the meantime by the Member State. In this regard, the Directive leaves the Commission a certain degree of discretion in choosing the most adequate remedy in case of the spread of a harmful organism. Indeed, Article 16(1) states that each Member State (and therefore also the Commission when amending national remedies) “shall take all necessary measures to eradicate, or if that is impossible, inhibit the spread of the harmful organisms concerned.”

According to the CJEU, by allowing the Member States to take “all necessary measures”, the Directive does not consider the list of necessary measures laid down in Article 23 as a numerus clausus. Conversely, it leaves room for other measures, which could be applied if necessary and supported by reliable scientific evidence.Footnote ¹⁶ Therefore, according to the EU judges, the Commission did not act beyond what was allowed by the Directive in this case, but – on the contrary – the Commission performed a duty laid down by the Directive itself. If the Directive – in order to protect plants’ health – allowed the Commission to adopt all necessary measures to eradicate or, at least, inhibit the spread of the pathogen concerned, such measures may also include the eradication of healthy plants within a radius of 100 metres around the infected plants, provided that this measure is proportionate to the objective pursued.

Secondly, the CJEU assessed whether the EU decision was consistent with the precautionary principle. The national court suggested that the contested measures were in breach of this principle since they were adopted in conditions of scientific uncertainty and without considering the latest scientific data.Footnote ¹⁷

The Court immediately acknowledged the broad discretion that the Commission has “when it adopts risk management measures”, and that “the validity of a measure adopted in that area can be affected only if the measure is manifestly inappropriate”.Footnote ¹⁸ Moreover, the Court highlighted that “although it is true that EFSA has not in its opinion proved the existence of a definite causal link between the bacterium Xylella and the rapid olive tree desiccation in the [Apulia] Region, that opinion nevertheless demonstrated (p 3), […] a significant correlation Footnote ¹⁹ between the bacterium and the occurrence of such a pathology.” Then, the CJEU recalled that “the precautionary principle, far from prohibiting the adoption of any measures in the absence of scientific certainty as to the existence or the extent of a health risk, may, in fact, justify, […] the adoption by the EU legislature of protective measures even if scientific uncertainties remain in that regard.”Footnote ²⁰

Thirdly, the CJEU examined whether the eradication measures laid down in Article 6(2) of the contested EU decision were in breach of the principle of proportionality. On this point, the Court referred again to the EFSA opinion of 6 January 2015, stating that insect vectors are able to “fly actively in the range of about 100 metres.” However, “they can probably be transported by wind over longer distances.”Footnote ²¹ Therefore, the available data suggested that a scale of 100 metres was an appropriate mean dispersal distance, and that “the Commission was entitled to take the view, having regard to its wide margin of appreciation of the subject matter, that the obligation to remove host plants within a radius of 100 metres around the infected plants immediately was an appropriate and necessary measure for preventing the spread of the bacterium Xylella from those plants by the insect vectors of that bacterium.”Footnote ²² Furthermore, “the fact that the Commission limited the obligation to remove host plants at a radius of 100 metres, although the vectors are capable of spreading the bacterium beyond that distance, shows, on the contrary, that that obligation was limited to what is necessary for attaining the objective sought.”Footnote ²³ As a consequence, taking into account the Commission’s wide margin of appreciation of the subject matter, the CJEU concluded that the eradication measures laid down in Article 6 of the contested decision were not in breach of the precautionary and proportionality principles.

IV Comment

The Xylella case raises the questions of the role scientific expertise has in EU public decision-making on risk,Footnote ²⁴ and to what extent EFSA opinions are “binding” on the Commission and the CJEU.

The answers to these questions are necessarily intertwined. Firstly, EFSA’s role is the one of risk assessor:Footnote ²⁵ it should inform the Commission’s decision-making process by satisfying its reason-giving requirements.Footnote ²⁶ In addition, the role of EFSA is not to fill scientific gaps at any cost, but to communicate the limits of scientific risk assessment, including knowledge gaps and scientific uncertainties.Footnote ²⁷ The analysis of EFSA thus becomes the decisive basis for the exercise of the Commission’s discretion,Footnote ²⁸ and in conditions of uncertainty the Commission has a wide margin of appreciation when making policy decisions on the basis of available scientific evidence.Footnote ²⁹

Furthermore, the role of EFSA has usually consisted of providing suggestions for possible risk management strategies, although, in some cases, the Commission has been found to have merely reproduced EFSA indications, acting “as a blind driver taking directions from the passenger in the back seat”Footnote ³⁰ (even in presence of scientific uncertainties). Such behaviour by policymakers has been described by some scholars as the uncertainty paradox: even though, “on the one hand it is generally recognised that science cannot provide decisive evidence on uncertain risks, on the other, policymakers and judicial authorities are increasingly resorting to science for a greater degree of certainty and conclusive evidence.”Footnote ³¹ The Xylella case confirms the existence of this paradox.

EFSA rated the risk of spread from established infestations of Xylella in Italy as very likely, and the overall potential negative consequences of the pest in the European territory as major, mainly because of the pathogen’s potential to cause disease in the risk assessment area once it establishes.Footnote ³² However, EFSA also stressed that “no treatment is currently available to cure diseased plants in the field and, most often, plants that are contaminated remain infected throughout their life or collapse quickly.”Footnote ³³ Given the lack of any suitable treatment, EFSA identified certain risk management measures to be adopted, which were then implemented by the Commission in its Decision 2015/789. In this regard, EFSA emphasised that, considering the wide range of hosts of Xylella, as well as the large number of potential insect vectors present within the EU, “eradication of the disease required drastic measures to be applied as soon as possible to the infected crop and to wild, unmanaged and ornamental plants that might host the bacterium, and to the insect vectors in the infected plots and their vicinity.”Footnote ³⁴

The European authority then specified that “eradication would consist here in removing all infected plants, including crops, unmanaged plants and ornamentals. Such eradication, […] to be effective, should be applied to all plants showing symptoms, asymptomatic plants found infected based on sensitive laboratory tests and neighbouring plants and should include all host plants of [Xylella].”Footnote ³⁵

The risk management measures suggested by EFSA in its opinion were thus carefully followed by the Commission in an attempt to stop the spread of the pathogen, and the overall assessment was used by the CJEU to assess the breadth of discretion for the EU intervention.

Although EFSA opinions are neither binding on the Commission nor directly reviewable by the EU judiciaryFootnote ³⁶ – in particular when they constitute only an “intermediate stage of a procedure intended to result in the adoption of the final decision”Footnote ³⁷ – the case law of the EU courts recognizes their de facto legally binding character.Footnote ³⁸ This is because EFSA holds the scientific expertise that the Commission lacks in undertaking risk assessments, which is the former’s main role in EU public decision-making on risk.Footnote ³⁹ On the other hand, the Commission plays the role of risk manager and it thus bears the political accountability for its decisions, even when it simply implements EFSA suggestions.Footnote ⁴⁰

Finally, the Xylella case shows how difficult it may be to establish the level of acceptable risk when environmental protection and food safety are at stake. Precautionary measures adopted in conditions of scientific uncertainty can be challenged before EU courts. In these cases, the judiciary is called upon to evaluate not only the proportionality of those EU precautionary measures,Footnote ⁴¹ but also the promptness of the policy intervention, which was agreed on under time constraints.Footnote ⁴² Nonetheless, the CJEU case law shows that a full assessment of those measures is technically impossible, as scientific uncertainty restricts the grounds for judicial review to the manifest appropriateness of the contested measures and the availability of less onerous and equally effective remedies. In conclusion, the Xylella case further confirms that broader discretion for policymakers implies narrower judicial control, since precaution is reviewable only with difficulty,Footnote ⁴³ and that the proportionality test for precautionary measures is a loose test, which recognises a broad margin of discretion for the Commission in choosing the most appropriate solution.