Abstract
This paper considers whether climate change falls within the scope of the 1997 United Nations Convention on the Law of the Non-Navigational Uses of International Watercourses (UN Watercourses Convention). General principles of treaty interpretation are used to examine various environmental obligations concerning the protection and preservation of ecosystems and the marine environment, pollution, harmful conditions, and emergency situations. While similar analyses have been conducted in relation to other treaties such as the United Nations Convention on the Law of the Sea, this paper represents a novel analysis with respect to the UN Watercourses Convention. This paper concludes that climate change may be implied into three obligations: the obligation to protect and preserve the ecosystems of international watercourses, the obligation to protect and preserve the marine environment, and the obligation to prevent or mitigate harmful conditions.
Introduction
Effective watercourse management requires an understanding of global challenges facing international watercourses. Climate change is one such prominent issue which causes wide-ranging but uncertain impacts on watercourses and other freshwater resources. 1 Despite this, the 1997 Convention on the Law of the Non-Navigational Uses of International Watercourses (‘UN Watercourses Convention’) – the dominant instrument governing the field of international water law – lacks explicit mention of climate change. The extent to which states are required to consider this issue in their shared management and use of watercourses under international water law is therefore unclear. This paper seeks to fill this gap by embarking upon an interpretative analysis of the UN Watercourses Convention to determine whether climate change falls within its ambit. The recent May 2024 advisory opinion of the International Tribunal of the Law of the Sea illustrates that it is indeed possible to read climate change into a framework instrument such as the United Nations Convention on the Law of the Sea ('UNCLOS') which is otherwise silent with respect to climate change. 2 Through presenting a novel analysis in relation to the UN Watercourses Convention, this paper also contributes toward an understanding of whether international water law is ‘climate-proof’. 3
It is well understood that watercourses are particularly vulnerable to climate change due to the increased volatility in rainfall frequency and intensity that comes with increased global temperatures. 4 However, the precise consequences of climate change on international watercourses can be difficult to identify and forecast. Matters such as geography, altitude, and latitude can result in stark differences in impact even within the same geographic region. For example, western parts of the semi-arid Sahelian region in West Africa are expected to experience significant decreases in peak river flows by the 2050s, whereas eastern parts can expect a significant increase. 5 It is in this setting of unpredictability and risk that climate change and the environmental obligations contained in the UN Watercourses Convention intersect.
Principles of Treaty Interpretation
The task of treaty interpretation in accordance with the Vienna Convention on the Law of Treaties (‘VCLT’) is well-trodden ground. Relevant key principles nevertheless call for restatement. The ‘general rule’ of treaty interpretation stipulated in Article 31 of the VCLT requires each treaty to be ‘interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose.’ Each of the specified elements must be synthesised in a simultaneous rather than sequential manner. This process, coined the ‘crucible’ approach, arose from the International Law Commission's (‘ILC’) Commentary to the Draft Articles which stated that ‘[a]ll the various elements, as they were in any given case, would be thrown into the crucible, and their interaction would give the legally relevant interpretation.’
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The remainder of Article 31 requires that any subsequent agreement between the parties, subsequent practice, and applicable rules of international law be taken into account ‘together with the context’, along with any special meaning given to a term by the parties. As described further below, while Article 31 provides objective means of interpretation, this interpretative approach must also be viewed in light of the jurisprudence of the International Court of Justice (‘ICJ’) which consistently places emphasis on achieving an interpretative result that reflects the intention of the parties.
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The tribunal in Rhine Chlorides reconciled the relationship between Article 31 of the VCLT and the approach of the ICJ in the following manner: It can thus be seen that international jurisprudence has adhered to the general rule of interpretation codified in Article 31 of the Vienna Convention. The Tribunal considers that this rule should be viewed as forming an integral whole, the constituent elements of which cannot be separated. Moreover, this is the approach that is now taken by the International Court of Justice and by certain international arbitral bodies. All the elements of the general rule of interpretation provide the basis for establishing the common will and intention of the parties by objective and rational means.
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In certain circumstances, an application of Articles 31 and 32 may result in an ‘evolutionary interpretation’ where text is read in a contemporaneous rather than historical fashion. Such an interpretation may occur when the meaning of text has changed over time, or the environment surrounding it.
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Although international courts and tribunals have frequently resorted to evolutionary interpretations in recent decades, the rationale justifying its use has been less consistent. As Fitzmaurice and Merkouris note, three broad justifications have emerged in the practice of international courts and tribunals.
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First, an evolutionary interpretation may be given where it is deemed necessary to give effect to the actual or presumed intention of the parties. The ICJ has emphasised this reasoning on several occasions;
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notably in Namibia, Gabčíkovo-Nagymaros Project, Dispute regarding Navigational and Related Rights, and Pulp Mills.
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Secondly, international courts and tribunals have had recourse to an evolutionary interpretation on linguistic grounds where a term may be considered ‘generic’. For instance, the ICJ has previously considered that generic terms such as ‘comercio’, ‘the territorial status of Greece’, and ‘the well-being and development’ must have been understood by the parties as possessing a meaning which could change over time.
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The Court consequently presumed in each case that the parties had intended for the meaning of the term to evolve. While this rationale appears to place particular emphasis on the ‘ordinary meaning’ aspect of Article 31 VCLT, the way the ICJ has employed this justification for adopting an evolutionary interpretation indicates that it is, ultimately, a particular method for giving effect to the intention of the parties. So much is made clear in the famous passage of the ICJ in its Dispute regarding Navigational and Related Rights judgment: there are situations in which the parties’ intent upon conclusion of the treaty was, or may be presumed to have been, to give the terms used — or some of them — a meaning or content capable of evolving, not one fixed once and for all, so as to make allowance for, among other things, developments in international law. In such instances it is indeed in order to respect the parties’ common intention at the time the treaty was concluded, not to depart from it, that account should be taken of the meaning acquired by the terms in question upon each occasion on which the treaty is to be applied.
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This notion of interpreting text in accordance with the intention of the parties is an endeavour which must be approached with diligence and a certain degree of hesitation. While the absence of a term from a treaty does not preclude its implication, it must be borne in mind that the intention of the parties cannot be invoked ‘to fill in gaps, or import into the treaty something which is not there’. 17
The UN Watercourses Convention
Progress toward the drafting and adoption of the UN Watercourses Convention first began to take shape in 1970 when the UN General Assembly requested the ILC to consider the topic of the law of non-navigational uses of international watercourses with a view to its progressive development and codification. 18 As Rieu-Clarke notes, owing to the complexity of this task, the ILC studied the matter for twenty years before it adopted its final set of Draft Articles. 19 Following its adoption in 1997, a further seventeen years passed before the Convention entered into force in 2014 upon its 35th ratification. The UN Watercourses Convention presently has thirty-nine state parties as at August 2024.
The substance of the UN Watercourses Convention is broadly divided across four key parts. Part II of the Convention, titled ‘general principles’, codifies three customary law obligations of critical importance to the field of international water law: the obligation not to cause significant harm (known as the ‘no-harm’ principle), the doctrine of equitable and reasonable utilisation, and the obligation to cooperate. 20 Part III of the Convention plays an essential role in regulating watercourse cooperation by setting out a notification and consultation procedure with regard to ‘planned measures’ that may affect an international watercourse. Finally, Parts IV and V of the Convention impose both general and specific obligations to protect, preserve, and manage international watercourses, including in the context of harmful conditions and emergency situations. When considering the role and function of the UN Watercourses Convention, special note must also be taken of the subtle reference made in the preamble to its ‘framework’ role. Indeed, when the UN Watercourses Convention is taken alongside the 1992 Convention on the Protection and Use of Transboundary Watercourses and International Lakes (hereafter ‘UNECE Water Convention’), these two instruments provide a ‘general normative background’ which complements an otherwise fragmented and uncoordinated system of international watercourse treaties. 21 This supplementary role is made clear through Article 3, which details the interaction between the UN Watercourses Convention and specific watercourse agreements.
Irrespective of its slow uptake in ratification, the UN Watercourses Convention plays an essential role in the global regulation and management of international watercourses. Not only do the content and principles enshrined within its text represent foundational concepts, but the ICJ has also referred to the UN Watercourses Convention when pronouncing on matters of customary international law. Most prominently, in its 2022 Dispute over the Status and Use of the Waters of the Silala judgment, the Court consistently looked to the text of the UN Watercourses Convention when considering the applicable customary international law regarding the definition of an international watercourse; the no-harm principle; the obligation to notify and consult; and the relevant factors and circumstances that must be taken into account in determining and assessing what constitutes equitable and reasonable use – even though both Chile and Bolivia were not parties to the UN Watercourses Convention. 22 The Court in its 1997 Gabčíkovo-Nagymaros Project decision also noted that the UN Watercourses Convention represented a ‘modern development of international law’ which had strengthened the doctrine of equitable and reasonable utilisation. 23 The Court's use of the UN Watercourses Convention in its jurisprudence is indicative of the prominent role played by the Convention in the broader context of international water law.
An Examination of Relevant Provisions
A perusal of the UN Watercourses Convention's thirty-seven articles reveals several obligations which, prima facie, present plausible avenues through which climate change may appear or otherwise be implied. This paper begins with an examination of Articles 20 and 23 of the UN Watercourses Convention which impose broad environmental obligations on states to protect and preserve international watercourses. Both obligations are considered to impose a due diligence standard and are therefore obligations of conduct rather than result. 24 The possible implication of climate change within obligations concerning pollution, harmful conditions, and emergency situations is then considered.
Obligation to protect and preserve ecosystems
Article 20 reads as follows: Watercourse States shall, individually and, where appropriate, jointly, protect and preserve the ecosystems of international watercourses.
The context of Article 20 further assists in determining the meaning and intended function of the provision. Article 20 is situated within Part IV of the Convention, which establishes a broad regime governing the protection, preservation, and management of international watercourses. The general nature of Article 20 stands in immediate contrast with the remaining provisions of Part IV, as these are instead directed at more specific matters such as flow regulation, pollution, the introduction of alien species, and the protection of installations. The fact that Article 20 ‘introduces’ Part IV also suggests that it is intended to possess a wider scope than the articles which follow it. This interpretation is confirmed by the ILC Commentary. 28 The broader context of the UN Watercourses Convention is also relevant to an understanding of the object and purpose of the treaty and its discrete provisions, including Article 20. Particular regard must be given to the Convention's framework character and preamble, which illustrate the intention of the parties to create a treaty that, inter alia, addresses ‘problems affecting many international watercourses’ and promotes the optimal and sustainable utilisation of watercourses ‘for present and future generations’.
When each of these matters are considered and synthesised together in the manner required by Article 31 of the VCLT – and particularly noting that the ordinary meaning of Article 20 and its context within Part IV suggest a provision of broad scope, which is also confirmed by reference to the ILC commentary – Article 20 may be read as a provision of general scope which requires states to preserve and protect international watercourses from all matters that may affect their ecosystems. Given the breadth of this obligation and the apparent sensitivity of ecosystems to external factors, it seems apparent that many modern environmental problems facing international watercourses are likely to fall within the ambit of this provision. Climate change, in particular, may impact upon the biotic and abiotic components of freshwater ecosystems in many critical ways. Effects upon water quality and quantity range from the complete modification of flow regimes due to changes in rainfall patterns through to specific impacts such as decreased solubility of oxygen. 29 Increases in sea level can also cause low-lying coastal freshwater ecosystems to become more saline. 30 These examples offer only a brief insight into the myriad of consequences for watercourse ecosystems. Overall, the hydrological regimes of freshwater ecosystems, generally considered to be the ‘major driver of fresh-water ecosystem structure and function’, are highly vulnerable and sensitive to climatic stimuli. 31 Having regard to the pervasive and wide-ranging impacts of climate change upon the ecosystems of international watercourses, climate change may therefore be considered a matter falling within the ambit of Article 20 of the UN Watercourses Convention when the provision is read in the broad manner described above. The consequence of this reading would be that states possess a due diligence obligation to ‘protect’ international watercourses from climate change impacts that may upset the ecological balance of international watercourses, 32 and ‘preserve’ watercourses by maintaining their ‘original or existing state.’ 33 As the ILC Commentary notes, this obligation to protect invokes the ‘precautionary principle’ in the sense that states must err on the side of caution in circumstances where scientific impacts are not yet clear or understood. 34
An interesting parallel may also be drawn between Article 20 of the UN Watercourses Convention and Article 192 of the UNCLOS which similarly prescribes an obligation of protection and preservation. Indeed, the ILC Commentary explicitly notes the similarity between the two.
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Unlike the UN Watercourses Convention, the corresponding provision under UNCLOS has received considerable attention from international tribunals. For example, the arbitral tribunal in the South China Sea Arbitration held that Article 192 ‘extends both to ‘protection’ of the marine environment from future damage and ‘preservation’ in the sense of maintaining or improving its present condition’.
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The ITLOS in its recent advisory opinion also provided detailed consideration of the scope, measures, and nature of the obligation under Article 192 in the context of climate change. It concluded that the provision: applies to all maritime areas and can be invoked to combat any form of degradation of the marine environment, including climate change impacts, such as ocean warming and sea level rise, and ocean acidification. Where the marine environment has been degraded, this may require restoring marine habitats and ecosystems. This obligation is one of due diligence. The standard of due diligence is stringent, given the high risks of serious and irreversible harm to the marine environment from climate change impacts and ocean acidification.
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Obligation to protect and preserve the marine environment
Article 23 imposes a similar obligation to that of Article 20, albeit with two consequential changes. It reads as follows: Watercourse States shall, individually and, where appropriate, in cooperation with other States, take all measures with respect to an international watercourse that are necessary to protect and preserve the marine environment, including estuaries, taking into account generally accepted international rules and standards.
While several instruments present plausible candidates as ‘generally accepted international rules and standards’ in relation to the protection and preservation of the marine environment, few are relevant when considering specific rules and standards concerning climate change. The 2015 Paris Agreement, concluded within the framework of the United Nations Framework Convention on Climate Change (‘UNFCCC’), represents one possible instrument to which all member states of the UN Watercourses Convention are party (albeit without the ratification of Libya and Yemen).
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It is first relevant to note that only one obligation under the UNFCCC explicitly mentions water resources. Article 4(1)(e) requires that states: Cooperate in preparing for adaptation to the impacts of climate change; develop and elaborate appropriate and integrated plans for coastal zone management, water resources and agriculture, and for the protection and rehabilitation of areas, particularly in Africa, affected by drought and desertification, as well as floods;
While the requirement to take into account ‘generally accepted international rules and standards’ must be given weight when interpreting the provision, the ordinary meaning and context of Article 23 nevertheless suggests that states must take action to protect and preserve the marine environment from all matters that may harm it. The impacts of climate change on the marine environment of watercourses are well known, 43 particularly given that the impacts to watercourses mentioned above have a consequential effect upon the marine environment downstream. Several climate impacts affecting the marine environment were also summarised by ITLOS in its recent advisory opinion, including ocean warming, marine heatwaves, sea level rise, and ocean acidification. 44 Having regard to these matters, as well as the ordinary meaning and context of the provision, an appropriately broad interpretation of Article 23 suggests that the obligation to take all measures necessary to protect and preserve the marine environment of international watercourses includes impacts caused by climate change.
Obligation to prevent, reduce and control pollution
Article 21(2) of the UN Watercourses Convention imposes an obligation on states concerning pollution. It is cast in the following terms: Watercourse States shall, individually and, where appropriate, jointly, prevent, reduce and control the pollution of an international watercourse that may cause significant harm to other watercourse States or to their environment, including harm to human health or safety, to the use of the waters for any beneficial purpose or to the living resources of the watercourse. Watercourse States shall take steps to harmonize their policies in this connection.
Despite some similarities in the definitions of pollution under Article 1(1)(4) of UNCLOS and Article 21(1) of the UN Watercourses Convention, differences in context and application make it difficult to determine whether GHGs fall within the meaning of pollution under the UN Watercourses Convention. Importantly, little scientific research exists to suggest that GHGs ‘directly’ alter the composition or quality of freshwater resources. Rather, ‘the question of how increasing atmospheric CO2 concentrations may affect freshwater systems has been left largely unanswered.’ 47 However, a lack of scientific evidence demonstrating a direct causal link does not necessarily put an end to the matter. This is because Article 21, like Article 20, incorporates the precautionary principle. 48 In any event, the indirect consequences of GHG emissions on watercourses, i.e., the climate change impacts described above, are well documented. How far this notion of ‘indirectness’ may be stretched is nevertheless unclear. Indeed, without some degree of limitation, one might wonder whether the causal link between human conduct and the alteration of the watercourse may be bridged by the ‘butterfly effect’. 49
This apparent ambiguity is resolved when the entirety of Article 21 is considered in context as required by Article 31(1) of the VCLT. Article 21(1) must first be read alongside its corresponding obligation in Article 21(2), which is only enlivened when harm caused by pollution is ‘significant’. The examples listed in Article 21(2) illustrate what may be considered ‘significant’ in the context of this provision: harm to human health or safety, to the use of the waters for any beneficial purpose, or to the living resources of the watercourse. 50 Of the multitude of impacts caused by climate change on watercourses such as increased drought risk, flood frequency, and desertification, it is certainly possible that some may enliven Article 21 in the sense that the harm caused may be ‘significant’. However, these environmental consequences are precisely the environmental situations regulated by Article 27 in Part V as harmful conditions. As explored further below, Part V of the UN Watercourses Convention is specifically directed at managing natural phenomena that can be influenced and mitigated through human intervention. This is of importance given that Article 31(2) of the VCLT, which requires provisions to be read in context, also requires consideration of any structure or scheme underlying a provision within a treaty. 51 An absurd result would therefore be achieved if Article 21 were interpreted so broadly that it covered the same environmental situations as Article 27. Instead, when the provisions are read in a complementary fashion, the interpretative result suggests that the ambit of Article 21 cannot be construed so broadly as to include GHGs as a form of pollution.
This interpretative result is confirmed through a further examination of ordinary meaning and context. Although the definition of pollution and the obligation do not prima facie preclude GHGs from the scope of the provision, the indicative list of ‘mutually agreeable measures and methods’ contained in Article 21(3) do not appear to contemplate or otherwise leave open an interpretation that may include atmospheric pollution or the emission of GHGs. Rather, references to ‘point and non-point sources’; ‘water quality objectives and criteria’; and the introduction of substances ‘into’ waters, all point toward a stricter interpretation of ‘pollution’ that does not capture atmospheric emissions with indirect environmental consequences.
Harmful conditions
Part V of the UN Watercourses Convention concerns harmful conditions and emergency situations. Given that both provisions under this Part require watercourse states to collectively respond to certain stimuli, it is appropriate to consider whether either provision possesses a meaning which may imply climate change into the legal framework.
Turning first to ‘harmful conditions’, Article 27 reads as follows: Watercourse States shall, individually and, where appropriate, jointly, take all appropriate measures to prevent or mitigate conditions related to an international watercourse that may be harmful to other watercourse States, whether resulting from natural causes or human conduct, such as flood or ice conditions, water-borne diseases, siltation, erosion, salt-water intrusion, drought or desertification. While it may be debated whether the harm results from the condition itself or from the effects thereof, there is no doubt that such problems as floods, ice floes, drought and water-borne diseases, to mention only a few, are of serious consequence for watercourse States. The present article is concerned with the prevention and mitigation of such conditions.
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This conclusion that the examples in Article 27 are illustrative of harmful conditions is reinforced by three additional matters in the English text. First, the explicit restatement of the word ‘conditions’ within the example ‘flood or ice conditions’ suggests that the items in the list are indeed conditions. Second, the reference made in the ILC Commentary to ‘such conditions’ after restating the listed examples further confirms this interpretation. And third, if the phrase ‘whether resulting from natural causes or human conduct’ is read as a non-defining relative clause – in the sense that it only provides non-essential additional information that could otherwise be removed from the sentence – then this further suggests that the examples listed after the clause are connected to the information preceding it.
These examples of ‘conditions’ are of consequence when considering climate change in the context of the provision. Latter items in the list such as erosion and desertification demonstrate that the meaning of ‘condition’ includes environmental processes. In turn, this serves to demonstrate that the meaning of ‘condition’ is not to be strictly construed as a mere assessment of the present physical state of an international watercourse, but also includes problems affecting it. Additionally, the inclusion of drought and desertification illustrates that ‘conditions’ may include large-scale processes which extend beyond the local drainage basin. Much like climate change, desertification is a complex phenomenon caused by a convergence of direct and indirect anthropogenic factors and affecting drylands around the world. 56 Several of the listed examples are also phenomena which can either be caused or exacerbated by climate change. For example, the March 2023 IPCC Synthesis Report states with high confidence that ‘[c]ontinued global warming is projected to further intensify the global water cycle, including its variability, global monsoon precipitation, and very wet and very dry weather’. 57 Climate change will also cause an increase in the frequency of compound heatwaves and droughts. 58 The travaux préparatoires may also be used to confirm the meaning of Article 27. The ILC Commentary illustrates that references to drought and desertification were specifically included due to ‘the severity of these problems, and of the fact that cooperative action among watercourse States can do much to prevent or mitigate them’. 59 Indeed, the ILC Commentary notes that the non-exhaustive list of conditions covers ‘most of the major problems’ which occurred to the ILC at the time of drafting in 1994. 60
Having regard to the meaning of ‘condition’ described above, it appears clear that climate change is precisely the kind of multifaceted phenomena that was intended to be captured by the provision at the time of drafting some thirty years ago. It is also apparent that climate change is now an issue of at least equal severity to the other phenomena listed in Article 27 and is one which cooperative action can do much to resolve. In this context, an interpretation of Article 27 in the manner required by Article 31 of the VCLT suggests that the meaning of ‘harmful condition’ broadly encompasses large-scale environmental processes such as climate change. This interpretative result is also consistent with an ‘evolutionary interpretation’ of the term, which appears necessary in the circumstances to reflect the common intention of the parties. 61 It is relevant to note in passing that climate change may not be the only modern problem which could feasibly fall within the meaning of this provision; for example, plastic pollution is another candidate that may reasonably fall within the scope of Article 27.
Emergency situations
In accordance with Article 28 of the UN Watercourses Convention, states are obliged to take certain actions in response to emergency situations which threaten or cause serious harm to international watercourses. This provision is of particular relevance given that climate change is increasingly described as a ‘climate emergency’.
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Under the UN Watercourses Convention, an emergency is defined by Article 28(1) to be: a situation that causes, or poses an imminent threat of causing, serious harm to watercourse States or other States and that results suddenly from natural causes, such as floods, the breaking up of ice, landslides or earthquakes, or from human conduct, such as industrial accidents.
An interpretation of this provision in accordance with Article 31 of the VCLT reveals that the concept of an ‘emergency’ under the UN Watercourses Convention does not include climate change for the following reasons. First, the ordinary meaning of the provision makes clear that it is only intended to capture events that are ‘sudden’. Second, paragraphs (2) and (3) only impose obligations of conduct upon States where an emergency originates within their territory. To read climate change in this context would yield an absurd result where climate change would need to ‘originate’ within a state for the obligation to ‘prevent, mitigate and eliminate’ to be enlivened. Further, when the provision is read in context, the notion of preparing ‘contingency plans’ under Article 28(4) strongly suggests that the provision is designed to cover matters which are unpredictable or unexpected.
Subsidiary means of interpretation confirm this conclusion. As Article 28 provides a non-exhaustive list of events or situations that may trigger the provision, the ejusdem generis rule may be used to identify what other events or situations may similarly fall within its scope. 63 In this regard, the ejusdem generis rule is a maxim of interpretation requiring general words to be given a meaning ‘of the same kind’ as special words around it. 64 Here, the items included in the Article 28 list – for example, landslides, earthquakes, and floods – all represent localised, unpredictable, and intermittent events. The same cannot be said for climate change. Indeed, the ILC Commentary to Draft Article 28 confirms that the provision is not intended to deal with prevention and mitigation like Article 27 and is instead focused upon sudden situations. 65 It follows that Article 28 of the UN Watercourses Convention cannot be interpreted in a manner such that climate change would constitute an ‘emergency’.
Conclusion
Climate change represents a critical challenge to the use and management of international watercourses. While its precise impacts will vary based on the characteristics of each watercourse, the broad implications are nonetheless well known.
At first glance, the absence of any explicit reference to climate change in the UN Watercourses Convention initially suggests that climate change is, quite simply, ‘not there.’ 66 Indeed, this paper concludes that this is true for provisions concerning pollution and emergency situations in Articles 21 and 26 of the UN Watercourses Convention respectively. However, the interpretative analysis undertaken in this paper suggests that climate change may be implied in three key environmental obligations. First, Article 20 of the UN Watercourses Convention requires states to protect and preserve the ecosystems of international watercourses against climate change. Second, climate change may be implied in Article 23 which requires states to protect and preserve the marine environment of international watercourses. Third, it may also be implied into Article 27 in a manner requiring states to take all appropriate measures to prevent and mitigate climate change as a ‘harmful condition’. Commonalities exist between Articles 20, 23, and 26 beyond their implicit inclusion of climate change; for instance, all three provisions concern obligations of protection and preservation and require states to fulfil their obligations individually and, ‘where appropriate, jointly’. Within the bounds set by these provisions, parties to the UN Watercourses Convention are therefore implicitly required to positively consider and account for climate change in the management and use of international watercourses.
A synthesis of the above conclusions also makes an important contribution toward an understanding of whether international water law is ‘climate proof’. The interpretative analysis conducted by this paper demonstrates the precise role played by several key environmental provisions of the UN Watercourses Convention. While this analysis highlights three provisions through which climate change may be implied in the UN Watercourses Convention, equally important is this paper's analysis regarding provisions in which it may not. This, in turn, may assist in directing and focusing future attempts to expand upon the relationship between climate change and the Convention. Although it is certainly possible for other international water law instruments including bespoke watercourse treaties to consider and incorporate climate change, the implication of climate change into a framework instrument contributes significantly toward the view that international water law is, at least to some degree, ‘climate proof’.
Footnotes
Funding
The author received no financial support for the research, authorship, and/or publication of this article.
Declaration of conflicting interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.