Evidence but not Empiricism? Environmental Impact Assessments at the International Court of Justice in Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua) and Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v. Costa Rica)

December 2015 was a landmark month for treaty-based developments in international environmental law, after the successful conclusion of the Paris Agreement (see Jorge Vinuales’ three-part analysis here, here, and here, and subsequent reactions from Annalisa Savaresi here and Po-Hsiang Ou here). However, one should not also overlook more modest jurisprudential developments arising from the International Court of Justice’s 16 December 2015 Judgment on the Merits in Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua) and Construction of a Road in Costa Rica along the San Juan River (Nicaragua v. Costa Rica). While the Court in this case continued to affirm as settled law that States have to conduct environmental impact assessments (EIAs) for projects that could result transboundary harm – even innovatively introducing provisional measures in 2011 that required parties to cooperate on environmental monitoring – the Court ultimately remained opaque on the method and criteria it used to assess the degree of “risk of transboundary harm” that would be sufficient to trigger a State’s obligation to conduct an EIA. It was a regrettably lost opportunity for the Court to provide practical and conceptual guidance to States on how to assess “significant risk of transboundary harm” which triggers the international legal duty of a State to conduct an EIA before starting the proposed activity.  The question of transboundary harm risk assessment has become increasingly urgent in recent years, particularly as more cross-border public-private partnership projects proliferate and States assume the international legal burden of conducting proper EIAs at the outset of any such cross-border PPP project.

To recall, Costa Rica had filed its Application with the ICJ, essentially alleging, among others, that Nicaraguan forces had committed various incursions and outright occupation of Costa Rican territory, along with dredging and canalization activities, that resulted in serious damage to its protected rainforests and wetlands affecting the Colorado River and the San Juan River in breach of international treaty obligations, including under the Ramsar Convention on Wetlands (Judgment, paras. 47-49). Costa Rica argued, in particular, that Nicaragua had breached the “obligation to carry out an appropriate transboundary environmental impact assessment, which takes account of all potential significant adverse impacts on Costa Rican territory” (Judgment, para. 49). In turn, in its own Application against Costa Rica, Nicaragua also alleged, among others, that by constructing a road running in Costa Rican territory along part of its border with Nicaragua, Costa Rica had caused transboundary harm and breached various international environmental obligations (the Ramsar Convention, the Agreement on Border Protection between Nicaragua and Costa Rica, the Convention on Biological Diversity, and the Conservation of the Biodiversity and Protection of Main Wildlife Sites in Central America) (Judgment, para. 50).

Since both parties alleged that the other’s acts were causing transboundary harm, the conduct of an EIA within proper legal parameters became a central issue in these cases. Costa Rica argued that Nicaragua had failed to carry out an appropriate EIA of its dredging works, also omitting to consult with and notify Costa Rica of such works. (Judgment, para. 100.) Nicaragua argued that it was Costa Rica that had failed to conduct a proper EIA before it commenced constructing the road along the Nicaraguan border. (Judgment, para. 146). Interestingly in this case, the Court rejected the Costa Rican claim that there was a significant risk of transboundary harm from the Nicaraguan dredging activities, while the Court accepted that there was such a risk to Nicaragua in regard to Costa Rica’s road construction project. Inexplicably, the Court was quite brief in its factual and evidentiary assessment of the former claim (on Nicaraguan dredging activities), while it then became quite detailed in its factual and evidentiary evaluation of the latter claim (on the Costa Rican road construction project).

In Pulp Mills on the River Uruguay the Court declared that an EIA is required “where there is a risk that the proposed industrial activity may have a significant adverse impact in a transboundary context, in particular, on a shared resource.” (Pulp Mills, Judgment on the Merits, para. 204). The Court was cautious in pointing out that States themselves determine the scope of EIAs:

“Consequently, it is the view of the Court that it is for each State to determine in its domestic legislation or in the authorization process for the project, the specific content of the environmental impact assessment required in each case, having regard to the nature and magnitude of the proposed development and its likely adverse impact on the environment as well as to the need to exercise due diligence in conducting such an assessment. The Court also considers that an environmental impact assessment must be conducted prior to the implementation of a project. Moreover, once operations have started and, where necessary, throughout the life of the project, continuous monitoring of its effects on the environment shall be undertaken.” (Pulp Mills Judgment on the Merits, para. 205. Italics added.)

With respect to the Costa Rican and Nicaraguan applications in the instant cases before it, the Court again affirmed its stance in Pulp Mills on the subjective content of an EIA and States’ broad discretion to determine the content of EIAs. Most crucially, the Court set out the litmus test that if there is a “risk of significant transboundary harm, the State planning to undertake the activity is required, in conformity with its due diligence obligation, to notify and consult in good faith with the potentially affected State, where that is necessary to determine the appropriate measures to prevent or mitigate that risk.” (Judgment, para. 104.) However, the Court was utterly silent on whether such an EIA was to be judged solely from the lens of the State determining the scope and content of an EIA and conducting the said EIA, or whether there are objective, empirical, or scientific criteria under international law for determining the existence of such significant risk of transboundary harm. Ultimately, the Court found that, as regards Costa Rica’s Application, Nicaragua “was not under an international obligation to carry out an environmental impact assessment in light of the absence of risk of significant transboundary harm” (Judgment, para. 108.) The Court reached its brief factual conclusion that “the evidence before the Court does not indicate that Nicaragua’s dredging programme has brought about any changes in the ecological character of the wetland, or that it was likely to do so unless it were to be expanded.” (Judgment, para. 109). The Court did not discuss or elaborate on how it conducted its assessment of the range of scientific evidence presented to show the risk of transboundary harm from Nicaragua’s dredging activities, instead appearing to give some weight to “Nicaragua’s commitment, made in the course of oral proceedings, to carry out a new environmental impact study before any substantial expansion of its current dredging programme.” (Judgment, para. 112.) Ultimately, on the issue of environmental damage, the Court also did not find any “convincing evidence that sediments dredged from the river were deposited on [Costa Rica’s] right bank…[or] that the dredging programme caused harm to its wetland…a causal link between [reduction in the flow of the Colorado river] and the dredging programme has not been established.” (Judgment, para. 119.)

In contrast, the Court proceeded to resolve the Nicaraguan Application with considerably more detail in exploring Nicaragua’s allegation that Costa Rica’s road project posed a significant risk of transboundary harm as to have warranted the conduct of an EIA. The Court observed that one possible way to assess the risk of significant transboundary harm is for the State in question to “conduct a preliminary assessment of the risk posed by an activity” (Judgment, para. 154), without expressly describing what that preliminary assessment would entail. The Court suggested that it would consider the “nature and magnitude of the project and the context in which it was to be carried out” (Judgment, para. 155) as one way to determine whether a project posed a risk of significant transboundary harm. The Court examined a whole host of factors and circumstances that it anticipated would have affected Nicaragua as regards Costa Rica’s road construction project: the project scale, planned location and proximity to the territory of the other State, the likelihood of sedimentation due to erosion, possibility of natural disasters in the area, geographic conditions of the river basin where the road was to be situated and possible large deposit of sediment from the road, “with resulting risks to the ecology and water quality of the river, as well as morphological changes”. (Judgment, para. 155.) The Court ultimately found that Costa Rica had “not complied with its obligation under international law to carry out an environmental impact assessment concerning the construction of the road.” (Judgment, para. 162. See also para. 173.)

The main conceptual difficulty with the current broad parameters in international law on States’ duties to conduct EIAs lies with how much – if any – actual empirical or scientific approaches are actually relied upon by the Court, in order to determine the existence of a “significant risk of transboundary harm” that triggers the duty to conduct an EIA in the first place. The line between the State’s discretion to conduct an EIA, and the Court’s demand for a preliminary impact assessment to determine the existence of a “significant risk of transboundary harm” warranting a fuller EIA, appears completely subjective and indeterminate. In the Costa Rican Application involving Nicaragua’s dredging activities, the Court simply articulated its factual conclusion that there was no such risk without showing its methodology for assessing the scientific evidence to reject the risk of damage to Costa Rican wetlands from the dredging activities. Considering that the Court’s 2011 Provisional Measures Order in this case explicitly granted Costa Rica the right to dispatch civilian personnel charged with environmental protection “only in so far as it is necessary to avoid irreparable prejudice being caused to the part of the wetland” (Provisional Measures Order of 8 March 2011, para. 86, item no. 2), it was puzzling that the Court was opaque as to how it ultimately assessed the scientific evidence presented to show the significant risk of transboundary harm to the Costa Rican wetlands protected under the Ramsar Convention. In contrast, in the Nicaraguan Application challenging Costa Rica’s construction of a road, the Court appeared more proactive in identifying various objective, empirical, and scientifically verifiable factors and possibilities that could create a significant risk of transboundary harm to Nicaragua.

To this end, the Court could have furthered the development of international environmental law by clarifying the definition and operational assessment of “significant risk of transboundary harm”, looking to authoritative empirical verifiability and the nuances of prevailing and evolving science applicable to such risk assessment. The Court missed the opportunity to draw insights from the International Law Commission’s 2001 Draft Articles on Prevention of Transboundary Harm from Hazardous Activities and Commentaries (hereafter, “ILC Commentaries to the 2001 Draft Articles”), Article 1 of which ties in the concept of significant risk of transboundary harm to the “physical consequences” of such activities, taking into consideration “developments in scientific knowledge” in the assessment of such risks (ILC Commentaries to the 2001 Draft Articles, paras. 15 and 16.) As the ILC acknowledged, “an activity may involve a risk of causing significant transboundary harm even though those responsible for carrying out the activity underestimated the risk or were even unaware of it. The notion of risk is thus to be taken objectively, as denoting an appreciation of possible harm resulting from an activity which a properly informed observer had or ought to have had.” (ILC Commentaries to the 2001 Draft Articles, para. 14) Due to its asymmetric analytical treatment and discussion of evidence in regard to Costa Rica’s Application (on Nicaraguan dredging activities’ impacts on the ecological character of protected wetlands) and Nicaragua’s Application (on Costa Rican road construction impacts on the surrounding river and terrestrial environment), much obscurity and ambiguity remains over the obligatory character and content of EIAs for activities posing “significant risk of transboundary harm”.  Visionary developments in international environmental law treaty-making such as the Paris Agreement, still contrast quite markedly with the more cautious march of international environmental jurisprudence as in these cases.