From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2023. All Rights Reserved.date: 10 December 2023
- Sustainable development — Natural resources — Fisheries — Marine environment, protection — General principles of international law — Continental shelf — High seas — UNCLOS (UN Convention on the Law of the Sea) — Global administrative law — Soft law
Published under the auspices of the Max Planck Institute for Comparative Public Law and International Law under the direction of Professor Anne Peters (2021–) and Professor Rüdiger Wolfrum (2004–2020).
1 The concept of common but differentiated responsibilities in international environmental law entails that while pursuing a common goal (see also Conservation of Natural Resources), States take on different obligations, depending on their socio-economic situation and their historical contribution to the environmental problem at stake. In particular since the 1990s, the concept has become prominent in international environmental law (see also Environment, International Protection). However, differentiating based on the socio-economic situation of States is not unique to international environmental law; its origins can be traced to the early 20th century. This contribution focuses on the concept of common and differentiated responsibilities in international environmental law, while briefly considering its early origins.
2 Article 405 (3) Versailles Peace Treaty (Versailles Peace Treaty ) constitutes an early expression of the concept. It is identical to current Art. 19 (3) Constitution of the International Labour Organization (International Labour Organization [ILO]), which provides that in framing labour conventions or recommendations due regard shall be given to ‘those countries in which climatic conditions, the imperfect development of industrial organization, or other special circumstances make the industrial conditions substantially different’ (see also Labour Law, International). Such conditions may provide a basis for modifying the general rules formulated in an ILO convention or recommendation and some ILO conventions implement Art. 19 (3) ILO Constitution by way of exceptions that a State Party may claim based on insufficient development of its economy or relevant social infrastructure (eg Art. 7 Convention No 183 concerning the Revision of the Maternity Protection Convention). Moreover, international trade law has since the conclusion of the General Agreement on Tariffs and Trade (‘GATT’) in 1947, recognized the special position of developing countries in Art. XVIII GATT (General Agreement on Tariffs and Trade [1947 and 1994]). This special position has found broader reflection in the amended Art. XVIII GATT and in Part 4 GATT, included in 1965, as well as in the Marrakesh Agreement Establishing the World Trade Organization (‘WTO Agreement’). Within the World Trade Organization (WTO), the differential treatment of developing States, besides facilitating technical assistance and capacity building, entails that reciprocity in mutual trade concessions, an important tenant of international trade law, may be released in the relationship between developing and developed States. Such releases are subject to negotiation between developing and developed States and the resulting preferential treatment is often of limited duration. In addition, the United Nations Convention on the Law of the Sea of 1982 (Law of the Sea) contains various references to the special position of developing States, especially where fisheries are concerned (eg Arts 61 (3) and 62 UN Convention on the Law of the Sea; see also Fisheries, Coastal; Fisheries, High Seas) and in its Part XI, on the regime of the international seabed area.
3 In international environmental law, the concept of common but differentiated responsibilities is expressed in Principle 12 Stockholm Declaration of the United Nations Conference on the Human Environment and in Principles 6 and 7 Rio Declaration on Environment and Development (Stockholm Declaration  and Rio Declaration ). It is, moreover, since the 1970s, reflected in the provisions of most multilateral environmental agreements (‘MEAs’; Environment, Multilateral Agreements).
4 The Rio Declaration currently provides the most generally accepted formulation of the concept of common but differentiated responsibilities. The first sentence of its Principle 6 provides: ‘The special situation and needs of developing countries, particularly the least developed and those most environmentally vulnerable, shall be given special priority’. Principle 7 Rio Declaration provides:
5 These terms point to the core of what constitutes the concept of common but differentiated responsibilities in international environmental law: a global partnership, linked to the duty to cooperate, in which States are to take on different obligations based on their situation, as determined by, in particular, their present (and future) developmental needs, historical contribution to environmental degradation, present contribution to the problem and their access to technological and financial resources. The basis of differentiation in the application of the concept has two components: it consists of a responsibility component which takes account of historical, current, and future contributions to environmental degradation; and a capabilities component, which reflects economic capacities to contribute to environmental protection. The concept links to a number of other environmental concepts, such as sustainable development, inter- and intragenerational equity (Intergenerational Equity; Equity in International Law), and polluter pays. The concept of sustainable development addresses the need to balance socio-economic considerations (Development, Right to, International Protection), while the concepts of inter- and intragenerational equity address, respectively, equity across generations and equity among members of a generation. According to the ‘polluter pays’ concept, it is the person or entity causing the environmental damage that should bear its costs. The interrelationship between these concepts can be characterized as follows: the concept of common but differentiated responsibilities constitutes a means of translating the concept of inter- and intra-generational equity to the inter-State level, the South-North context in particular, with a view to attaining sustainable development by placing responsibility on actors actually causing or having caused environmental degradation.
6 Most MEAs do not explicitly refer to the concept of common but differentiated responsibilities, but instead contain substantive obligations that implement the concept. The United Nations Framework Convention on Climate Change (‘UNFCCC’; Climate, International Protection) and the Paris Agreement are exceptions. Article 3 UNFCCC, entitled ‘Principles’, provides in its first paragraph:
In the Paris Agreement, the concept of common but differentiated responsibilities is referred to in several instances. It provides that the parties to the Paris Agreement are guided by the principles of equity and common but differentiated responsibilities and respective capabilities in the light of different national circumstances (Preamble), and that the Paris Agreement will be implemented to reflect these two principles (Art. 2 (2)). The concept must specifically be reflected in the party’s nationally determined contribution (‘NDC’) (Art. 4 (3)) and long-term low greenhouse gas emission development strategies (Art. 4 (19)).
7 MEAs implement the concept of common but differentiated responsibilities in a variety of ways. Firstly, MEAs may include a grace period for developing States. A pertinent example is Art. 5 (1) Montreal Protocol on Substances that Deplete the Ozone Layer (‘Montreal Protocol’), ie the protocol to the 1985 Vienna Convention for the Protection of the Ozone Layer (Ozone Layer, International Protection). It allows developing States a period of 10 years before they must comply with the general substantive rules of the Montreal Protocol. Secondly, MEAs may provide substantive obligations only for developed and economy in transition States. The Kyoto Protocol to the United Nations Framework Convention on Climate Change (‘Kyoto Protocol’) provides an example. It requires developed and economy in transition States, and not developing States, to comply with agreed greenhouse gas emission reductions (Art. 3 and Annex A Kyoto Protocol; see also Emissions Trading). Note that the Paris Agreement has moved away from this approach, since it requires all parties to submit NDCs. Thirdly, most MEAs make implementation by developing States conditional on the transfer of technology and financial means from developed States (Technology Transfer), eg Art. 4 (7) UNFCCC and Art. 20 (4) Convention on Biological Diversity (Biological Diversity, International Protection). These provisions are to a large degree implemented through so-called financial mechanisms (eg Art. 21 Convention on Biological Diversity and Art. 21 Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification, particularly in Africa; Desertification), which are linked to the International Bank for Reconstruction and Development (IBRD) (see paras 9–12 below). Fourthly, some MEAs provide special substantive rules for the relationship between developed and developing States. The 1995 amendment to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal banning the transboundary movement of hazardous wastes between developed and developing States provides an example of this approach (Conference of the Parties to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal ‘Decision III/1’; see also Hazardous Substances, Transboundary Impacts; Hazardous Wastes, Transboundary Impacts). Lastly, the environmental compliance control mechanisms that function in the context of most MEAs provide that in the case of non-compliance a State may be offered assistance in order to bring it back into compliance with the agreement (eg Conference of the Parties to the Convention on Biological Diversity ‘Decision BS-I/7’ para. III (1) (c), establishing the compliance mechanism for the Cartagena Protocol on Biosafety to the Convention on Biological Diversity).
8 During the negotiations of the Paris Agreement, the basis of differentiation in the application of the concept of common but differentiated responsibilities became a contentious issue. During the 1990s when the concept gained prominence, the distinction between developed and developing States in MEAs was largely justified by the pre-existing economic realities in which developing States were regarded as a homogeneous group. By the time of the negotiations of the Paris Agreement, developing States had become an economically heterogeneous group and in some instances their economies had surpassed those of developed States. Developed States thus became increasingly discontented about the static bipolar understanding of the concept of common but differentiated responsibilities anchored in the UNFCCC and the Kyoto Protocol, and argued for the reflection of actual current economic realities in the interpretation of the concept. The qualification ‘in light of different national circumstances’ that was added to each and every articulation of the concept in the Paris Agreement is thus to be understood as a compromise between developing States—who were adamant to maintain the status quo of the UNFCCC—and developed States—who wished the changing economic capabilities of developing States to be reflected in the Agreement. To move away from basing the concept of common but differentiated responsibilities on a pre-determined and static dual classification of developing and developed States and qualify the concept on the basis of the actual current circumstances of the parties gives the concept a dynamic, adaptable, and flexible character. The main operationalization of this shift of approach occurs in the mitigation pillar of the Paris Agreement. Here, climate change mitigation is based on a system of self-differentiation in which the parties to the Paris Agreement set their own NDCs. The Paris Agreement should, however, not be understood as a radical deviation from the bipolar differentiation of responsibilities in the UNFCCC and the Kyoto Protocol. For example, pursuant to Art. 4 (4) Paris Agreement, developed States are to take the lead in absolute emission reduction targets, while developing States should—for now—continue to enhance mitigation efforts and are only encouraged to strive—over time—for an economy-wide emission reduction.
C. Institutional and Decision-Making Structure
9 The concept of common but differentiated responsibilities is at the source of the complex institutional and decision-making structure of international environmental law. At the basis of this structure are the various MEAs and in particular their provisions that require the transfer of technology and financial means and the establishment of financial mechanisms for this purpose. This transfer to a large extent takes place through funds linked to the IBRD such as the Global Environment Facility (GEF), which functions as the financial mechanism for most MEAs. In addition, the IBRD and the GEF itself also administer other funds that contribute to the implementation of MEAs, such as the UNFCCC. Relevant examples are the Climate Investment Funds, the Carbon Partnership Facility, and the Least Developed Country Fund. Due to this manner of proceeding, the IBRD and the GEF are in a position to play a coordinating role in international environmental law, especially in the South-North context.
10 Based on decisions taken by the conferences of the parties (‘COPs’) of MEAs competences have thus been attributed to the IBRD and funds linked to the IBRD (eg Conference of the Parties to the Convention on Biological Diversity ‘Decision I/2’, identifying the GEF as the [interim] financial mechanisms for the Convention on Biological Diversity; see also Conference [Meeting] of States Parties; Environmental Treaty Bodies). As a result, a shift in decision-making patterns has taken place: from the one-State-one-vote and in practice mostly consensus decision-making pattern prevalent in MEAs, to the weighted voting system employed in the IBRD or to the various decision-making patterns employed in the funds (see also International Organizations or Institutions, Voting Rules and Procedures). On most of the governing bodies of the funds, including the GEF, donor and recipient States are now equally represented.
11 MEAs themselves also administer funds. The Montreal Protocol, for example, administers the Multilateral Fund for the Implementation of the Montreal Protocol (‘Montreal Fund’), which is used to finance ozone reduction–related projects in developing States, and the Adaptation Fund, which is designed to support implementation of the Kyoto Protocol, was administered within the climate change regime. The World Heritage Fund occupies a similar position in relation to the Convention for the Protection of the World Cultural and Natural Heritage of 1972 (Cultural Heritage; World Natural Heritage).
12 This complex institutional and decision-making structure has given rise to a body of norms and decision-making patterns, which, especially due to the large scale involvement of international institutions, qualify as international administrative law (see also Global Administrative Law). Within this body of law, international institutions exercise decision-making powers that can be characterized as of a public law nature. Decisions taken by COPs, IBRD, GEF and various funds referred to in this section provide examples.
13 As mentioned above, the concept of common but differentiated responsibilities can be understood as a translation of the concept of intragenerational equity to the inter-State level. At that inter-State level it signals a move away from the consequences associated with the formal equality of States, a prominent assumption in the traditional doctrine of international law (States, Sovereign Equality). Formal equality entails that de iure all States are assumed to be equal and subject to the same rights and duties, regardless of their socio-economic characteristics. This assumption meant that international law did not play a significant role in decreasing, or even maintained the de facto inequalities between developing and developed States. During the 1970s, these inequalities resulted in claims for the establishment of a New International Economic Order (NIEO) on the part of developing States. While the NIEO never emerged, the articulation of environmental problems as of common concern provided developing States with an opportunity to voice their demands regarding a more equitable international legal order and assistance from developed States (see also Developing Country Approach to International Law). These demands, as is illustrated by the concept of common but differentiated responsibilities, have resounded in international environmental law.
14 There is, however, another side to the story of the concept of common but differentiated responsibilities. This side of the story concerns the manner in which it has been implemented, with a focus on incremental costs and conditionalities attached to the economic benefits that developed States may obtain as a result of certain mechanisms that implement the concept.
15 The notion of incremental costs entails that developed States, through the GEF, contribute to the extra costs that developing States incur when they contribute to the protection of the global environment through the implementation of MEAs. In other words, a developing State that plans to undertake a project for national benefits may request funding from the GEF for purposes of transforming that project into a more environmentally friendly project with benefits for the global environment. An example would be the transformation of a national power generation project from a coal to a gas-based energy project, where the transformation would be eligible for GEF funding. Payment thus is not for the protection of the environment in developing States, even though that is to be a most likely effect of such a project, but for the protection of the global environment from which developed States also profit.
16 The transfer of financial means and technology, furthermore, is conditional upon developing States meeting standards set out in MEAs and especially in the decisions subsequently adopted by COPs to MEAs and by the decision-making bodies of the various funds referred to above.
17 In addition, developed States and the private sector in developed States may obtain economic benefits from projects that support implementation of MEAs in developing States based on the concept of common but differentiated responsibilities. Cases in point are projects implemented on the basis of the flexible mechanisms of the Kyoto Protocol, such as projects undertaken under the Clean Development Mechanism, in which private sector actors are entitled to participate. In this case, developed States and the private sector in developed States may pursue economic profit by obtaining cheap emission reduction units through carbon reduction projects in developing States. These units may be used by developed States to meet their targets under the Kyoto Protocol or can be sold at a profit on the global carbon market. It is envisaged that market-based mechanisms, in addition to non–market-based mechanisms, will continue to play a role in the implementation of the Paris Agreement.
18 These elements in conjunction with the institutional setting set out above have led some commentators to suggest that sustainable development and the notion of common but differentiated responsibilities as well as other elements of contemporary international (environmental) law have enabled the continued subordination of developing States to the will of developed States and international institutions in which developed States have a major say.
E. Legal Status
19 The concept of common but differentiated responsibilities clearly has normative implications, ie implying commitments, possibly duties, on the part of developed States vis-à-vis developing States. The concept, however, is unlikely to qualify as a rule, given that it cannot apply in an all-or-nothing fashion. It is thus more likely to qualify as a principle. Whether it has legally binding status as a principle is more difficult to determine as it is not an explicit element of the texts of most MEAs, even if these MEAs provide means of implementing the principle (see paras 6–7 above). Within these MEAs, the parties are legally bound by the norms, rules, or principles formulated to implement the concept of common but differentiated responsibilities. In terms of general international law, the concept of common but differentiated responsibilities, then, is most likely to qualify as a principle of international environmental policy or soft law that has had a profound effect on international environmental law, both on its substance and on its institutional structure (see also General International Law [Principles, Rules and Standards]; General Principles of Law). The UNFCCC and the Paris Agreement are the exceptions to the above. Within the climate change regime, the concept of common but differentiated responsibilities qualifies as a legally binding principle given its explicit inclusion in both instruments. Noteworthy in this respect is that in the Netherlands v Urgenda case, both the Hague Court of Appeal and the Hoge Raad (the highest court and a court of cassation in the Netherlands) took into account the concept of common but differentiated responsibilities in committing the Netherlands to attain a 25% reduction of greenhouse gas emissions by 2020, compared to 1990, based on the duty of care that it owes citizens pursuant to Arts 2 (Right to life; Life, Right to, International Protection) and 8 (Right to respect for private and family life; Privacy, Right to, International Protection; Family, Right to, International Protection) European Convention for the Protection of Human Rights and Fundamental Freedoms (‘ECHR’; European Convention for the Protection of Human Rights and Fundamental Freedoms ). This was the first occasion on which the concept of common but differentiated responsibilities played a role in the interpretation of greenhouse gas emission reduction obligations under the climate change regime by a national court.
20 The concept of common but differentiated responsibilities has affected international environmental law, and perhaps also international law in general, in a fundamental manner. It has altered the discourse by changing the nature of what are considered to be valid arguments. Most importantly it has given developing States a basis for claiming that their position is to be taken into account in the formulation of treaty regimes. Moreover, it has given developing States a basis for pursuing the position that they will not accept or will only accept minimal obligations unless developed States transfer funds and technology to them. In terms of the protection of the environment one might argue that this development has come at a price: economic, in addition to ecological, considerations figure prominently in negotiations. This is true both for developed and developing States. It also means that environmental problems are being recognized for what they are: problems that if they are to be addressed require a fundamental restructuring of economic and social relations at local, national and global levels. Such considerations of course do not make the negotiations any easier as was illustrated by the negotiations for the Paris Agreement. However, these negotiations also show that the concept of common but differentiated responsibilities is adaptable and can be instrumental in achieving agreement to collectively move forward, even in very contentious environmental policy areas.
Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal (done 22 March 1989, entered into force 5 May 1992) 1673 UNTS 57.
Cartagena Protocol on Biosafety to the Convention on Biological Diversity (done 29 January 2000, entered into force 11 September 2003) 2226 UNTS 208.
COE ‘Convention for the Protection of Human Rights and Fundamental Freedoms’ (signed 4 November 1950, entered into force 3 September 1953) 213 UNTS 221 (European Convention on Human Rights).
Conference of the Parties to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal (3rd Meeting) ‘Decision III/1: Amendment to the Basel Convention’ (18–22 September 1995) UN Doc UNEP/CHW.3/35.
Conference of the Parties to the Convention on Biological Diversity ‘Report of the First Meeting of the Conference of the Parties to the Convention on Biological Diversity: Decision I/2: Financial Resources and Mechanism’ (28 November–9 December 1994) UN Doc UNEP/CBD/COP/1/17, 32.
Conference of the Parties to the Convention on Biological Diversity ‘Report of the Third Meeting of the Conference of the Parties to the Convention on Biological Diversity: Decision III/1: Pending Issues Arising from the Work of the Second Meeting of the Conference of the Parties’ (4–15 November 1996) UN Doc UNEP/CBD/COP/3/38, 46.
Conference of the Parties to the Convention on Biological Diversity Serving as the Meeting of the Parties to the Cartagena Protocol on Biosafety ‘Report of the First Meeting of the Conference of the Parties Serving as the Meeting of the Parties to the Protocol on Biosafety: Decision BS-I/7: Establishment of Procedures and Mechanisms on Compliance under the Cartagena Protocol on Biosafety’ (23–27 February 2004) UN Doc UNEP/CBD/BS/COP-MOP/1/15, 98.
Constitution of the International Labour Organisation (signed 9 October 1946, entered into force 20 April 1948) 15 UNTS 40.
Convention on Biological Diversity (concluded 5 June 1992, entered into force 29 December 1993) 1760 UNTS 79.
Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification, particularly in Africa (opened for signature 14 October 1994, entered into force 26 December 1996) 1954 UNTS 3.
Convention for the Protection of the World Cultural and Natural Heritage (adopted 16 November 1972, entered into force 17 December 1975) 1037 UNTS 151.
General Agreement on Tariffs and Trade (adopted 30 October 1947, entered into force 1 January 1948) 55 UNTS 187.
General Agreement on Tariffs and Trade 1994 (adopted 15 April 1994, entered into force 1 January 1995) 1867 UNTS 187.
ILO ‘Convention No 183 concerning the Revision of the Maternity Protection Convention (Revised) 1952’ (adopted 15 June 2000, entered into force 7 February 2002) 2181 UNTS 253.
Kyoto Protocol to the United Nations Framework Convention on Climate Change (adopted 11 December 1997, entered into force 16 February 2005) 2303 UNTS 162.
Marrakesh Agreement establishing the World Trade Organization (adopted 15 April 1994, entered into force 1 January 1995) 1867 UNTS 154.
Montreal Protocol on Substances that Deplete the Ozone Layer (adopted 16 September 1987, entered into force 1 January 1989) 1522 UNTS 3.
Netherlands v Urgenda Foundation Gerichtshof Den Haag [The Hague Court of Appeal] (9 October 2018) Case No 200.178.245/01 ECLI:NL:GHDHA:2018:2591.
Netherlands v Urgenda Foundation Hoge Raad der Nederlanden [Supreme Court of The Netherlands] (The Hague 20 December 2019) Case No 19/00135 ECLI:NL:HR:2019:2006.
Paris Agreement (adopted 12 December 2015, entered into force 4 November 2016) UN Doc FCCC/CP/2015/10/Add.1, 21.
Treaty of Peace between the Allied and Associated Powers and Germany (signed 28 June 1919, entered into force 10 January 1920) (1919) 225 CTS 188 (Versailles Peace Treaty).
UN Conference on Environment and Development ‘Rio Declaration on Environment and Development’ (14 June 1992) UN Doc A/CONF.151/26/Rev 1 vol I, 3.
UN Conference on the Human Environment ‘Stockholm Declaration of the United Nations Conference on the Human Environment’ (16 June 1972) UN Doc A/CONF.48/14/Rev 1, 3.
United Nations Convention on the Law of the Sea (concluded 10 December 1982, entered into force 16 November 1994) 1833 UNTS 3.
United Nations Framework Convention on Climate Change (with Annexes) (adopted 9 May 1992, entered into force 21 March 1994) 1771 UNTS 107.
Vienna Convention for the Protection of the Ozone Layer (adopted 22 March 1985, entered into force 22 September 1988) 1513 UNTS 324.