Impact case study database

Border dispute resolution: Thorne’s research (R4) as an expert witness provided crucial evidence to permanently settle a 160-year border dispute that had soured relations between Costa Rica and Nicaragua for decades (Impact a (Ia), R8). An ICJ Judge wrote in his testimonial, “ By assisting the Court in reaching its conclusions and giving its judgment, his [Thorne’s] evidence helped to bring what appears to be an end to a border dispute which has been a source of acrimony for well over a century and which was the subject of five cases between Costa Rica and Nicaragua” (Ib). The Court’s Written Proceedings (R4) make multiple references to the research conducted by Thorne (R4-6), its outcomes and his interpretations of the significance of the research findings to the merits of the cases judged by the Court (R8). Additionally, Thorne gave oral evidence, delivered under cross-examination by counsel for Nicaragua, re-examination by counsel for Costa Rica, and questioning by the judges during the Merits Case, to qualify his written evidence and comment on claims made by Costa Rica and Nicaragua, and the other experts (R7). The Coordinator of the Office of International Litigations of the Ministry of Foreign Affairs writes in his testimonial, “ I commend Professor Thorne for his deep knowledge, his skill in steering the work of the team and, above all his independence, which together resulted in the truth about the illegality of Nicaragua’s actions and their environmental impacts being clearly laid out before the Court” (Ic).

In its judgment of December 2015 (R8), based on cartographic and fluvial evidence submitted by Thorne from the research he carried out (R4-6), the Court made clear that the alignment of the Río San Juan and, hence, the border between Costa Rica and Nicaragua remains as depicted in the 1858 Treaty of Limits, the Cleveland Award of 1888 and the first and second Alexander Awards of 1897 (R4, p. 362, I.4.3; R8, para. 76). It follows from this ruling that, by occupying land on the Costa Rican side of the river in October 2010, Nicaragua did violate Costa Rica’s territorial sovereignty. Experts appointed by Nicaragua relied on a map published by Google. The Court accepted Thorne’s conclusion that Google Maps misrepresented the border (R4, R7, Id).

The Court also accepted Thorne’s evidence (in: R4, p. 448, 11.6.2; R8, para. 119) that, far from being natural, the first canal dredged by Nicaragua was intended to artificially and illegally divert the Río San Juan from its natural course, but ultimately concluded (also consistently with that evidence) that dredging performed up to 2015 within the river itself had not damaged Costa Rican territory or the Colorado River, a distributary of the Río San Juan (R8). On the basis of Thorne’s evidence (in R4, R7/3 paras. 33-34 and R8, para. 127), the Court judged that, by excavating two further canals in the disputed area in September 2013, Nicaragua illegally aggravated and extended the dispute. In addition, as is clear in the Written Documents for Nicaragua v. Costa Rica (R5), based primarily on Thorne’s research (in R5, R6 & R7) the Court rejected Nicaragua’s claim that Costa Rica had violated Nicaragua’s territorial integrity (R8, para. 196). It found no basis for Nicaragua’s claim of environmental damage to its territory and reiterated Costa Rica’s right to navigate the Río San Juan (R8, paras. 193-194, 201-202, 223).

This impact was strengthened by the fact that Costa Rica accepted all of Thorne’s research (R4-R7), even when it did not support their arguments; for example in relation to Costa Rica’s claim that dredging by Nicaragua had damaged Costa Rican territory (R8, paras. 105, 119). This establishes Thorne’s independence as an expert witness. As the Coordinator of the Office of International Litigations of the Ministry of Foreign Affairs writes in his testimonial, “Professor Thorne demonstrated a deep understanding of mapping, rivers and environmental science in the way he worked with me in setting up and steering the scientific and engineering studies performed by my technical team. He then demonstrated his independence as an expert witness by not only showing how the resulting science supported most of Costa Rica’s legal positions, but also showing how it refuted some of its other positions in very specific matters” (Ic).

Nicaragua also accepted most of Thorne’s evidence, challenging it only in relation to a few issues that were of marginal relevance to the judgments. The Senior Counsel for Costa Rica, who is currently serving as a judge at the ICJ, writes in his testimonial, “ Throughout this complex process, Professor Thorne was the principal expert (scientific) witness for Costa Rica and the principal scientist involved on either side. His skills and the clarity and fairness of his approach to scientific issues were undoubtedly impressive, and evidently underpinned the court’s findings…” (Ie).

The law and environmental damage: The second impact stems from the Court’s ruling that, by carrying out dredging, excavation and tree felling activities in the disputed area, Nicaragua inflicted significant environmental harm on Costa Rican territory. Such was the severity of the harm, which involved clearing of rainforest and excavating wetlands protected under the Ramsar Convention, that the Court decided, for the first time in its history, to award damages to a nation state (in this instance Costa Rica) in restitution for the environmental harm done by another state (here Nicaragua) in its territory (R8). The ICJ Judge writes that Thorne’s work “ contributed to the assessment of damages by the Court in the first case in which it has awarded damages for environmental harm and only the second case in its 75 year history in which it has awarded damages at all” (Ib). Damages of USD378,890.59 (If, section VI), which were paid in full by Nicaragua on 23 March 2018, included compensation not only for restoration costs in respect of the wetland, and expenses incurred in gathering evidence, but also for impairment and loss of environmental goods and services (If, section III). In establishing that the environment has a financially accessible value and awarding damages in respect of its degradation, the ICJ set an important precedent in International Law for the effective adjudication of environmental claims within the international legal order. Through its clarification of the relevant principles of state responsibility, this ruling will influence all future cases where one nation state unlawfully harms the environment of another. This point has been recognised by international environmental groups and authorities including the International Union for Conservation Nature who stated that this case, “marks a clear affirmation that environmental damage includes ecosystem services. The Court has recognized the important value of biological diversity and its services” (Ig).

Who has benefited and how they have benefited

The most immediate beneficiary of these impacts is the country of Costa Rica, whose complaints were upheld, whose interpretation of the Treaty of Limits and Awards of Cleveland and Alexander was vindicated, and who received compensation from Nicaragua. As noted by Costa Rica’s Foreign Minister in a letter of thanks to Thorne, the ICJ judgment means that, “boundaries between Costa Rica and Nicaragua stand completely defined, providing security and stability to both countries” (Ia). In 2019, Costa Rica was ranked the 33^rd most peaceful nation in the World, a ranking which it is only able to maintain through support from international law.

Other beneficiaries of the impact of Thorne’s research are peaceful nations threatened by militarily aggressive neighbours, globally. This is because Costa Rica v. Nicaragua confirmed that it is possible for a nation to protect its sovereign territory through recourse to the rule of law, rather than by force of arms. Thorne’s evidence (based on research in R4) has therefore contributed to strengthening forms of dispute resolution and access to justice. Beyond this, all nations stand to benefit from the court deciding, for the first time in history, to award damages for environmental harm. This will deter states from undertaking activities liable to cause environmental harm to another state, especially in the case of Ramsar-listed wetlands, wet woodlands, and other landscapes of international importance (Ih). Specifically, an ICJ Judge states Thorne’s evidence “ has made an important contribution to the development of international environmental law in relation to the activities of States along a river border. It is early to assess how the law will develop in this area but, in my opinion, the 2015 and 2018 Judgments, along with an earlier judgment (Pulp Mills on the River Uruguay (Argentina v. Uruguay), ICJ Reports 2010, p. 14), have made a major contribution to the development of international environmental law and are the most significant judgments of their kind” (Ib).

Of six previous environmental cases brought before the ICJ, none had been resolved successfully in favour of the environment. This case breaks that mould. The legal professionals involved in the proceedings also benefitted from the use of an independent expert witness in providing technical and scientific validity to the geographical issues presented by both sides.

Thorne’s research and its impacts were subsequently disseminated regionally and globally through the news media (TV and print) and this coverage has influenced public discourse on border disputes (e.g. Ii), river management, and environmental law (Ih, Ij). Thorne’s research has also been (and continues to be) referenced, taken up and critiqued by academic end-users in geographical, legal, environmental and political disciplines (e.g. Ik).