The Common but Differentiated Responsibilities Principle: Changes in Continuity after the Durban Conference of the Parties



The common but differentiated responsibilities (CBDR) principle has played a major part in the post-2012 climate change negotiations. However, the rise of emerging economies and the multiplication of State categories have called the initial compromise under the United Nations Framework Convention on Climate Change (UNFCCC) into question and, until now, no balance between the conflicting claims of States has been found. Meanwhile, the principle is still not fixed in terms of its formulation, legal nature and practice. Although it enabled agreement on the UNFCCC in the 1990s, the principle has also contributed to climate negotiation deadlocks. As a result, it appears to be fading in the 2011 Durban decisions, giving place to general contextual norms. Moreover, the decision on the Durban Platform, through which the post-2020 negotiations will take place, does not refer to the principle at all. Still, it is clear that differential treatment will have a structuring role in the post-2020 negotiations. This article examines the Durban outcomes in the light of the CBDR principle, with a view to analyzing the prospects of differential treatment in international climate change law.


Deeply rooted in the old notions of fairness and equity,1 the idea of differential treatment between developed and developing countries started to appear in international environmental law in the last quarter of the twentieth century. It addresses the fact that environmental issues, such as climate change, have too much of a universal impact for the answer to be ‘solely a matter of domestic jurisdiction’,2 and acknowledges that ‘imposing equal obligations on subjects of law that are unequal in relevant ways may be perceived as unjust if they exacerbate inequalities or impose unfair burdens on those least able to bear them’.3 During the 1972 Stockholm and 1992 Rio Conferences, negotiators took hold of this idea. The preamble of the Stockholm Declaration states: ‘the developing countries must direct their efforts to development, bearing in mind their priorities and the need to safeguard and improve the environment. For the same purpose, the industrialized countries should make efforts to reduce the gap between themselves and the developing countries’ (emphasis added).4 In the twenty-year period between Stockholm and Rio, developing countries kept fighting to ensure different national situations were taken into account. Acknowledging historical differences as well as differences in terms of economic and social development, States then ‘crafted a burden-sharing arrangement rooted in differential treatment’5 in order to achieve a regime characterized by a universal scope rather than uniformity in parties' obligations.6 The 1992 Rio Declaration embodies this ‘burden-sharing arrangement’ in its Principle 7:7

States have common but differentiated responsibilities. The developed countries acknowledge the responsibility that they bear in the international pursuit to sustainable development in view of the pressures their societies place on the global environment and of the technologies and financial resources they command. (emphasis added)

At Rio, countries adopted the United Nations Framework Convention on Climate Change (UNFCCC),8 which was subsequently followed by the adoption of the Kyoto Protocol in 1997.9 Bringing together 195 Parties, the Convention today has a universal scope and constitutes the main legal instrument on climate change.10 The principle of common but differentiated responsibilities (CBDR), expressed in Article 3.1, helped make this universality possible. By addressing the demand of developing countries to see differences in national circumstances taken into account, the CBDR principle has become the basis of the differentiated obligations for developed and developing countries. Since 1992, the principle of common but differentiated responsibilities has been used repeatedly in the negotiations and has been reiterated in key texts structuring the regime, including the 1997 Kyoto Protocol. It has therefore been said that the principle of CBDR is ‘best reflected in the climate regime’.11

Still, the UNFCCC does not perfectly incorporate the Rio Declaration's definition of CBDR. Whereas the Rio Declaration clearly refers to historical contributions of developed countries to environmental degradation, these contributions are only mentioned in the preamble of the UNFCCC.12 Furthermore, the UNFCCC wording adds the mention of ‘respective capabilities’ to CBDR. Article 3.1 of the Convention, expressing CBDR, states that

[T]he Parties should protect the climate system for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof.

Since developed countries were strongly opposed to any reference to their historical emissions, it was important to put responsibilities and capabilities on an equal footing. Hence, the last sentence of Article 3.1, giving them ‘the lead’ in combating climate change, is more a reference to their larger obligations under the Convention and their greater technological and financial capacities than to their historical contribution to environmental degradation.

One of the main reasons why historical emissions were not taken into account in the Convention and the Protocol is because CBDR, as expressed in 1992, represented a political consensus on what should be the commitments and actions of developed and developing country parties. However, the multiplication of State groups within the developing countries category and the rise of emerging economies – some of them being today's major greenhouse gas emitters – have called this initial compromise into question. Trying to reach any new consensus comes down to a simple question: what is common and what is differentiated between developed and developing countries?13 While negotiating new differentiated obligations, questions concerning the legal nature and scope of the CBDR principle have re-emerged. Given that the formula of the principle is so general, however, it has led to diverging interpretations. For instance, the United States and some other developed countries have chosen to focus on ‘common’ responsibilities, asking emerging economies to take on commitments. Thus, for the United States, ‘developed and developing countries share common challenges in meeting all of their economic, social and environmental needs’14 and ‘all countries have a common responsibility to take actions that will promote’ clean development.15 Meanwhile, Australia considers that ‘if key developed country mitigation commitments … were separated from commitments and actions relating to non-Parties to the Kyoto Protocol and advanced developing economies … it would be more difficult to assess comparability of effort’.16

By contrast, emerging economies, small-island developing States and other developing countries emphasize ‘differentiated’ responsibilities, asking developed country parties to keep leading the fight against climate change. Thus, for Brazil, ‘significant steps must be taken to promote, facilitate and finance the transfer of, access to and development of environmentally sound technologies and know-how, particularly fromdeveloped countries to developing countries, for both mitigation and adaptation’.17 For Tuvalu, ‘the allocation of responsibility for emissions reductions should be based on historical emissions… . Annex I Parties have contributed approximately 75% of cumulative global emissions of CO2. A global breakdown of historical responsibility can be represented as: Kyoto Annex I Parties 45.75%, the United States 29.25%, Non-Annex I Parties 25%.’18 And Bolivia calls ‘on developed countries to commit to deep emission reductions in order to advance the objective of avoiding dangerous anthropogenic interference with the climate system and its consequences, to reflect their historical responsibility for the causes of climate change, and to respect the principles of equity and common but differentiated responsibilities in accordance with the UNFCCC’.19

At the fifteenth Conference of the Parties (COP) in Copenhagen in 2009, progress was obstructed ‘for one thing, by the continuing uncertainty about whether the United States will undertake serious action to curb its emissions [and] for another [because] Copenhagen negotiations for the first time have given serious attention to developing country [greenhouse gas] emissions’.20 Paradoxically, as the Copenhagen example shows, the CBDR principle, which made it possible to create the international climate regime in the 1990s, has also contributed to the post-2012 negotiation difficulties. More accurately, it is the question of how the principle would be implemented through differentiated obligations that led to difficulties in Copenhagen rather than its very existence. And on this point no consensus was reached. On the contrary, the Copenhagen Accord21 left ‘most substantive disagreements unresolved – in particular … the future of the Kyoto Protocol, the legal form and architecture of the future legal regime, and the nature and extent of differential treatment between developed and developing States’.22

After Copenhagen, the COP in Cancún gave ‘a new lease of life’23 to the climate regime. Still, the Cancún Agreements are characterized by the bottom-up/pledge and review approach that had already been sketched in Copenhagen.24 Moreover, an analysis of the pledges made so far reveals an ‘increasing parallelism between the mitigation commitments and actions taken by developed and (some) developing countries’,25 showing that the consensus reached only represents the lowest common denominator of parties' interests. The creation of the Ad Hoc Working Group on the Durban Platform for Enhanced Action in 2011 launched ‘a process to develop a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties’.26 While not returning to a ‘targets and timetables’ approach as used in the Protocol, and without establishing the legal form of the future agreement, consenting to the launch of this new process has ensured the continuation of the climate regime, at least for the time-being.

Since differentiated obligations are at the core of the regime and since these obligations are ‘based on’ or ‘taking into account’ CBDR, it is obvious that the principle plays a central part in shaping the new texts of the regime and negotiating future obligations. Yet, when analyzing the wording of the Durban decisions, it seems that the practice of CBDR is changing. Indeed, while references to Decision 2/CP.1727 and the Bali Action Plan,28 which both contain the principle, can be found in it; Decision 1/CP.17 creating the Durban Platform makes no reference to CBDR as such. The objective to develop ‘a protocol, another legal instrument or an agreed outcome with legal force under the Convention’ (emphasis added) does link the future text to the UNFCCC and, therefore, indirectly to CBDR. However, this does not change the fact that the Decision does not refer to the principle as do all the important texts developed under the climate regime.29 More broadly, out of the eighteen other decisions adopted in Durban, only Decision 2/CP.17 quotes CBDR, Article 3 and the principles of the Convention,30 whereas Decision 3/CP.17 only refers to the latter.31 And yet, references to equity or special and national circumstances are more frequent in Decision 2/CP.17 than they were in Decision 1/CP.16. The question then arises whether or not this evolution of the CBDR practice through the Durban decisions is leading to changes in the principle's legal nature, scope and consequences, and whether this may have implications for the climate regime itself. At first blush, the answer would be ‘yes’. However, even though some major changes seem to take place with respect to the practice of the principle and the setting of common and differentiated obligations, one cannot help but noticing that vagueness and uncertainties that have characterized its legal nature remain unchanged.

In order to give a complete view of these elements of CBDR, the next part of this article assesses the legal nature and scope of the principle. The article then studies the impacts of the Durban decisions. The insights on CBDR drawn from this analysis are discussed in the conclusions, as they offer a glimpse of the future of the principle in the regime.


In the climate regime reference is made to common but differentiated responsibilities ‘and respective capabilities’. Therefore, we should talk about ‘CBDRRC’, and not only about ‘CBDR’ as in Rio, especially in light of developed countries' resistance to the mentioning of historical responsibilities. It is notable that CBDRRC is often linked to other principles or contextual norms. Thus, in Article 3.1 of the UNFCCC, CBDRRC is invoked in conjunction with the notion of equity. Furthermore, elsewhere in the Convention, references can be found to parties' CBDR ‘and respective capabilities and social and economic conditions’,32 or CBDR ‘and specific national and regional development priorities, objectives and circumstances’.33 Other documents go even further, speaking of parties' CBDR ‘and specific national and regional development priorities, objectives and circumstances’.34 Finally, some countries use formulations that seem to mean CBDR but are not expressed in the same wording. For instance, some speak of the principle ‘of shared but differentiated responsibility’,35 or ‘of shared but specific responsibility’.36 Do these formulations have the same meaning as CBDR? Do they have the same legal nature? There is no straightforward answer here, but if generality in meaning is a characteristic of legal principles, the names of such principles are usually clear. The various different wordings of CBDR certainly do not help making it a clear autonomous binding obligation.

Having said that, it is necessary to take a closer look at the CBDR principle to assess its legal nature. This leads us, in first instance, to Article 38 of the Statute of the International Court of Justice (ICJ),37 which lists the sources of international law and subsidiary means for the determination of rules of law. Even though this order is somewhat unorthodox, the lack of decisions and the diversity of doctrine make it easier to begin the analysis with these subsidiary means. So far, no judicial decision has been given specifically on CBDR,38 and doctrine is largely irrelevant here since most authors are divided on this question. Indeed, some authors see CBDR as ‘an emerging principle of international environmental law’,39 whereas others see it as ‘framework principle’40 with a unique philosophical basis, failing ‘even to rise to the level of soft law’.41 Finally, it seems certain that CBDR does not meet the conditions for the recognition of a general principle of law recognized by civilized nations. These principles usually appear in foro domestico and are common to most domestic systems. At the moment, however, there is no corroborating evidence that CBDR is common to most domestic systems, especially since State practice on CBDR is still evolving.

Pursuant to Article 38 of the ICJ Statute, another possibility for CBDR to have a clear and defined legal nature is customary international law. To be recognized as such, there should be ‘evidence of a general practice accepted as law’ or, more accurately, a ‘settled practice … accompanied by the opinio juris sive necessitatis’.42 Although there may be abundant evidence of the use of CBDR in treaties and COP decisions, there is no such evidence of a general practice accepted as law.43 Indeed, parties rather tend to use their own definition of CBDR in order to support their arguments. For instance, to try to pressure developed countries in complying with their obligations, most developing countries use formal wordings that seem to imply a compelling legal nature. For China, ‘the principle of common but differentiated responsibilities … must be acknowledged as a cornerstone of the system’.44 Peru, Colombia, Costa Rica, Ecuador, Mexico, Nicaragua and Panama provide their own conception of the principle of CBDR in the context of reducing emissions from deforestation and forest degradation. While recalling CBDR, the countries argue that reducing emissions from deforestation forms ‘a unique opportunity to enhance the effective participation of developing countries in the climate regime on a “voluntary” basis, while also providing industrialized countries an opportunity to positively fulfill their historical commitments for additional financing to support forest conservation and reduce deforestation in developing countries’.45 Developed countries clearly understood these attempts to modify the scope of the principle or create a semblance of rule of law and have consistently sought to counter it. While referring to the ‘principle’ of CBDR, Australia gives a good example of the developed countries' position on the matter in the context of the Kyoto Protocol's compliance mechanism:

Other principles have been suggested … such as the principle of common but differentiated responsibility. It is not obvious to us what role such principles could play in a compliance system for the Kyoto Protocol. In any case, we do not consider that much time should be spent attempting to articulate and explicitly reflect ‘principles’ in the development of the compliance system. Nor do we see the need to reflect explicitly any principles in the language that sets out the procedures and mechanisms.46

Over the years, this position on principles has been widely supported by developed countries. Although Australia's statement is explicitly related to the Protocol's compliance system, it clearly shows the developed countries' refusal to associate with principles when establishing international procedures and mechanisms – and, by doing so, obligations – because they cannot predict what consequences such principles will entail in the future.

Finally, the chapeau of Article 3.1 of the Convention states that ‘the Parties shall be guided, inter alia, by the following’ (emphasis added). Therefore, CBDR appears as one ‘guide’ in applying the Convention rather than a binding rule included in the text. As a consequence, it seems possible to affirm that the CBDR principle ‘cannot be declared a rule of customary international law’.47

The last source listed in Article 38 of the ICJ Statute is treaties and conventions. In both the Convention and the Protocol, CBDR appears in operational clauses, and not just the preambles. Like other treaty provisions, the principle is thus binding inter partes. But the question remains: what, then, is the precise content of this principle? There is no simple answer here since the wording of CBDR remains somehow unsettled, always general, and States are only ‘guided, inter alia’ under Article 3.1 of the UNFCCC. Therefore, it seems that CBDR forms only an ethical basis for legally differentiated obligations (as set out in Article 4 of the Convention and Article 3 of the Protocol or in the operational clauses of COP decisions).48 Moreover, since it does not contain any compelling implications, the principle cannot be used in international courts as a basis for State responsibility.

In addition to the usual sources of Article 38 of the ICJ Statute, CBDR could be regarded as a general principle of international law because of its ‘high level of abstraction and extreme generality’.49 These principles differ from the general principles of law recognized by civilized nations mentioned in Article 38 in that they directly result from international law while the latter first appear in domestic legal systems. Even though there are no clear criteria for the recognition of such general principles, two constants emerge: they can appear through court decisions50 or through the ‘endorsement of States’.51 Here, the adoption of universal declarations (such as the Rio Declaration) or treaties (such as the UNFCCC) could be seen as endorsements of CBDR by States. However, as mentioned above, CBDR is not expressed in the same way and does not have the same scope in those texts. Furthermore, existing general principles of international law (such as the principle of State consent52 or the principle according to which limitations of State sovereignty cannot be presumed53) are usually confirmed through case law. Until today, CBDR has not been used as a general principle of international law by international adjudicators. However, this may of course change in a similar way that, for instance, the Arbitral Tribunal in the 2005 Iron Rhine Case recognized the principle of sustainable development as a general principle of international law.54

Finally, even though their legal nature and binding force is still unclear, COP decisions are interesting to look at, as no treaty was adopted on climate change since 1997. In the 2010 Cancún Agreements it seems that what was a necessary effort of harmonization was undertaken. In the decision, all references to differentiation – except one55– are expressed under the wording of CBDRRC as used in the Convention.56 The Durban decisions have preserved this improvement, keeping a unique name for a principle all too volatile. But when referring to them, the decisions keep using general wording such as ‘recalling … Article 3 paragraph 1’,57 or ‘in accordance with their’58 CBDRRC in preambles, and ‘guided by the principles of equity’59 and CBDRRC or ‘guided by the principles of the Convention’60 in operational clauses. It remains uncertain how clauses like ‘guided by’ should be understood. Thus, regarding the nature of CBDR or its legal scope, no further precision or other progress can be found in COP decisions. And even if this was the case, one would first have to question the legal nature, and by doing so, the binding force of these texts before considering any change in their writing as a clear evolution of the legal nature of CBDR. Here, the ambiguity of formulations such as ‘taking into account’, ‘recognizing’ or ‘guided by’ CBDR tends to confirm the status of the principle as a philosophical basis for other differentiated obligations rather than signifying a change in its nature or scope.

Questions regarding CBDR's legal nature, meaning and consequences therefore remain unaddressed and contested.61 Most developing countries see the principle as a binding rule, but such a view is not tenable. While being a clause of the Convention and therefore being a source of international law, the principle by itself cannot be taken as a binding legal rule. On the contrary, it seems clear that CBDR remains for now a framework principle. It does not directly establish a clear goal, and differentiated obligations are and remain the results of negotiations and of the political will of States.

Does this mean that the CBDR principle has no legal force whatsoever? Of course not. More precisely, the legal scope of the principle has three different effects: an effect in structuring the regime, one on its orientation and a third one on the interpretation of legal texts of the regime.62 In structuring the regime, as the basis of differentiated obligations, the CBDR principle has been made the cornerstone in the fight against climate change. Thus, when referred to in COP decisions, the CBDR principle is ‘taken into account’. Or decisions are ‘guided’, adopted ‘on the basis of’ or ‘in accordance with’ CBDR.63 In a report of the Subsidiary Body for Implementation (SBI), the expression ‘with due regard to’ CBDR is used.64 Other references are made to Article 3 or Article 3.1 of the Convention; decisions then being ‘guided by’, adopted ‘in the context of’ or ‘in accordance with’, or ‘recalling’ Article 3.65 In orienting the regime, CBDR is the meeting and focal point of developed and developing States' positions in the negotiations. Since the principle is the basis of differentiated obligations, which in turn form the core of the regime, CBDR is inherently related to the negotiations of future obligations. CBDR thus helps coordinating the fight against climate change and building the regime. Finally, with regard to the interpretation of climate texts, the CBDR principle falls under Article 31, paragraphs 2 and 3 of the 1969 Vienna Convention, which concern the interpretation of treaties, as it is quoted in the operational clauses of both the Convention and the Protocol.66 Therefore, it could be used to interpret these two treaties and the obligations they set out.

In sum, as opposed to principles such as the principle of prevention, used by the ICJ in 1997,67 or the principle of sustainable development, recognized as a general principle of international law,68 it is possible to say that the CBDR principle, while being included in the climate treaties and thus binding inter partes, is not a rule of international law and therefore has no autonomous binding force – especially because its legal nature and content remain disputed.69 On the contrary, the role of CBDR seems to be to form a philosophical and ethical basis for differentiated obligations. This is the view of most developed countries, but the climate negotiations have clearly shown that some developing countries, such as India, do not share this opinion. Meanwhile, least developed States and small-island developing States are asking for stronger action through binding commitments from both developed and emerging economies. On these points, the Durban decisions offer no advance, as their references to CBDR tend to confirm this assessment, ensuring the continuity of the legal controversy. And yet, when analyzing the Durban decisions as a whole, it really seems that major changes are appearing on the practice of CBDR as a basis for differentiated obligations. Indeed, while the idea of differential treatment remains strong, it looks like there has been a shift in the conception of States' responsibilities under CBDR. Even though it is still too early to say if this constitutes a new path for the principle, the content of the decisions needs to be carefully studied since, while ensuring the continuity of the regime, this outcome could also represent a new conception of CBDR in the future climate regime.


When reading the Durban decisions, one thing becomes clear. Far from what could have been expected, the practice of the CBDR principle is changing, sometimes mentioning Article 3, but mostly referring to general notions such as equity, national circumstances and specific needs of developing countries.70 More importantly, however, neither the principle of CBDR nor any mentions of equity and differences in national circumstances appear in the decision creating the Durban Platform.71 Even though the two negotiation tracks of the Ad hoc Working Group on Long-term Cooperative Action (AWG-LCA) and the Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol (AWG-KP) remain operational – at least until the next COP in Doha – the Durban Platform is the only one to have, as a clear objective, the development of ‘a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties’72 by 2015. While it is not possible to foresee what precise obligations will be included in such an agreement, and even though its legal form is not yet fixed, parties have already affirmed that it would be binding,73 making it a major step forward.

Least developed countries, small-island developing states, South American countries along with the European Union, Brazil and South Africa (but not India) have been the key advocates for a new binding agreement. While most developing countries want to see CBDR recognized as involving a clear differentiation between different categories of States, developed countries are still opposed to a legally binding principle and have instead pleaded for increased uniformity in parties' obligations (especially the United States).74 It is thus clear that developed and emerging economies (especially the United States and India) do not agree on how to implement CBDR. This raises the question whether the changes in the practice of CBDR and its disappearance from Decision 1/CP.17 were a precondition set by developed countries to accept the establishment of the Durban Platform. Indeed, to developed parties, any reference to CBDR ‘must [now] be interpreted in the light of contemporary economic realities’.75

Two ways out have been to link the future instrument to the Convention,76 and to refer to contextual norms more often in the other decisions. The phrase ‘under the Convention’ ensures that a future text is indirectly linked to Article 3 of the UNFCCC. The use of differential treatment through contextual norms rather than principles is echoed in other international environmental agreements like the Convention on Biological Diversity and the UN Convention to Combat Desertification that, while referring to ‘particular conditions and capabilities’77 or ‘special needs and circumstances’78 chose not to implement the CBDR principle. The Vienna Convention for the Protection of the Ozone Layer79 and its Montreal Protocol80 also do not make any references to CBDR, in this case because they were adopted in 1985 and 1987, respectively, before CBDR emerged in international law. However, from 1992 onwards, following the adoption of the Rio Declaration, the UNFCCC and the formulation of CBDR, Meetings of the Parties to the Montreal Protocol have often referred to the principle as a way to express the differentiation put in place in the Treaty.81 It remains to be seen whether the absence of the principle in the Durban decision mean that the agreement to come will be the first text of the climate regime not referring to CBDR. It is clear that there is still room for differentiation in the decision, and parties' arguments over the principle are also clearly not yet finished.

Even though the practice of the principle itself is changing, the idea of differential treatment still features in the Durban outcome as the basis of differentiated obligations and assistance. On reporting obligations, the decisions ensure the implementation of obligations and review mechanisms defined in the 2010 Cancún Agreements82 with, respectively, an ‘international assessment of emissions’ related to targets for Annex I parties83 and an ‘international consultation and analysis of biennal reports’ for developing countries.84 For these two processes, the SBI is confirmed as the body in charge of reviewing. On mitigation, Durban decisions, like the Cancún decisions, are divided between ‘nationally appropriate mitigation commitments or actions by developed country Parties’ and ‘nationally appropriate mitigation actions by developing country Parties’.85 Here, one will notice that the word ‘commitment’ only concerns developed countries. However, some emerging economies have agreed to take on commitments under a future agreement, and the outcome of the AWG-LCA in Durban relating to developing countries states: ‘recognizing that developing country Parties are already contributing and will continue to contribute to a global mitigation effort in accordance with the principles and provisions of the Convention’.86 Thus, the role of emerging economies and developing countries in fighting climate change is growing.

Assistance also plays an important role in the Durban decisions. Following the Convention, which states that ‘the extent to which developing country Parties will effectively implement their commitments under the Convention will depend on the effective implementation by developed country Parties of their commitments … related to financial resources and transfer of technology’,87 the decisions still take into account the special situation of developing countries, particularly that of small-island developing States and least developed countries. Texts even refer to a ‘special flexibility’ for the latter two categories.88 Moreover, as in Article 4.7 of the Convention, the AWG-LCA text indicates that ‘social and economical development and poverty eradication are first and overriding priorities of developing country Parties’.89 In addition, three separate parts of the text relate to finance,90 technology transfer91 and capacity building.92 Furthermore, numerous references to Article 4.7 of the Convention can be found in Decision 2/CP.17. For example, developing countries ‘will continue to contribute to a global mitigation effort … depending on provision of finance, technology and capacity-building support by developed country Parties’93; they will hand in their first biennal report according to ‘their capabilities and level of support provided for reporting’,94 and ‘the extent to which developing country Parties will effectively implement their commitments under the Convention will depend on the effective implementation by developed country Parties of their commitments under the Convention related to financial resources and transfer of technology’.95

With the rise of emerging economies, it has become clear for some time now that developed countries cannot fight climate change alone. Parties have acknowledged this fact in the Durban decisions. Accordingly, developed and emerging economies have agreed to negotiate a new binding accord through the Durban Platform. Following the United States' view, pleading for more uniformity under the future regime, a new perspective could arise, focusing on a common responsibility to limit emissions, under which all developed and emerging economies could adopt the same type of commitments. This would be consistent with the ultimate objective of the Convention to stabilize greenhouse gas concentrations at a level preventing dangerous anthropogenic interference with the climate system,96 and would be in accordance with the original concept of CBDR, under which ‘common’ means that there is a universal responsibility to protect the environment ‘for present and future generations’.97 Moreover, such a path still offers the possibility to differentiate quantified emission reduction or limitation obligations (QELROs) according to countries' responsibilities and capacities. Indeed, while being submitted to the same type of obligations, it is still possible to differentiate on the basis of the stringency of these obligations. This would be something that has never been achieved before and would be a significant development for the future of the climate regime.

Choosing such a path would also allow a new conception of differentiation to appear. Since 1992, Annex I parties (with commitments to reduce emissions) have always consisted of members of the Organization for Economic Cooperation and Development (OECD) and countries with economies in transition – usually the developed or industrialized countries. And originally the main criterion for including a State in an Annex was the level of economic development. This situation was criticized by Annex I parties. For instance, Australia states that

since the Convention was adopted in 1992 no work has been done to better differentiate the responsibilities of Parties beyond the simple list of Parties in Annex I and Annex II to the Convention. Annex II is based on which States were members to the OECD in 1992, and Annex I included additional States that were undergoing the process of transition to a market economy. Neither list reflects current realities.98

Croatia also pleads that the ‘division into Annex I countries and non-Annex I countries was established almost two decades ago and does not reflect the current status with regard to economic potential for action and to emissions’.99 Thus, developing a new text under which developed and emerging economies would be submitted to the same type of obligations would mean that the simple criterion of economic development would be overcome, and that current and future emission levels will also be taken into account in the setting of differentiated obligations. Altogether, this would be a turning point in the ‘traditional’ conception of State categories under CBDR, but also a major achievement of the Durban COP since several emerging economies (notably the BASIC countries – Brazil, South Africa, India and China) are today, along with developed countries, the major greenhouse gas emitters. However, it would not mean that the economic criterion would disappear, as it is still of importance in matters of finance, technology transfer and capacity-building.

Nevertheless, having all parties submitted to differentiated QELROs is clearly not the only possibility of evolution for the climate regime. It is indeed possible to imagine that countries could have different types of commitments, with some countries taking on QELROs, and others adopting renewable energy targets or energy-efficiency targets. India would probably be more inclined to support such orientations. Similarly, other criteria than economic development and current and future emissions could be taken into account. Countries' mitigation potential and costs of mitigation are two elements that could also be considered in setting the differentiated obligations. In any case, even though emerging economies agreed with the Durban decisions, including Decision 1/CP.17, there is still a long road ahead. The Durban COP did not end the debate on universality versus uniformity, which will surely endure in the negotiations in the coming years. Furthermore, the Durban decisions alone do not offer guarantees for better results in fighting climate change. Indeed, the 2010 Cancún Agreements broke with the earlier system of differentiated obligations by moving towards a growing symmetry between mitigation commitments and actions taken, respectively, by developed and certain developing countries.100 If there is a certain ‘levelling up’ in developing countries obligations (especially on reporting), there is a clear ‘levelling down’ in developed countries commitments.101 As Rajamani puts it: ‘Since the political conditions for strengthening the overall mitigation effort are missing, such symmetry has been achieved at the cost of ambition.’102 The Durban decisions, while ensuring the negotiation of a new binding agreement, did not modify the Cancún Agreements, and therefore follow the same line of growing symmetry – at least for now.

Finally, on the subject of assistance, even though great importance is attached to finance, technology transfer and capacity-building in the decisions, no great progress was made on practical implementation by developed country parties. For instance, Durban ensured the establishment of the Green Climate Fund, but whilst the fast-start finance for 2010–2012 has generally been committed,103 it remains to be seen if the promised contributions to the Fund will be paid on time. Indeed, with respect to finance, developed countries usually refuse to pledge amounts if developing countries do not specify the actions they are going to take. Meanwhile, developing countries usually do not develop programmes of action if they cannot foresee the financing that will be available and how it will be organized.104

Whatever happened at the Durban COP, the outcome is what it is. But parties have to realize that any change in the conception or practice of CBDR may have important consequences for the whole regime. The Cancún Agreements have paved the way for Durban, which introduced what could be a new vision of future international climate law. A blind criticism of this path would not be productive. Still, one thing is clear: the objectives presented by parties are insufficient to achieve the long-term global goal set in the Convention.105 Therefore, whatever the approach taken at Doha and afterwards, the agreement to be designed through the Durban Platform will have to set commitments high enough for developed and emerging economies, otherwise it is unlikely that the Convention's ultimate objective of stabilizing ‘greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system’ will be achieved.106


After Cancún, the climate regime still lacked serious commitments from developed and emerging economies. After Durban, it seems that this stage will now be reached since these countries agreed to negotiate, before 2015, a new agreement in which those commitments should be defined. However, the legal form of this future agreement is still not certain and it is not possible, at the moment, to foresee what the agreement will contain. Still, the negotiations provide a great opportunity to clarify the future place and meaning of CBDR. Indeed, the clearer this will be, the clearer State categories taken into account and obligations they are subjected to will be; and then, the easier compliance and review will be for parties and the treaty bodies. Though the continuation of differential treatment in the climate regime seems unquestionable, uncertainties still surround the future of the CBDR principle, especially after the Durban decisions, since it is not yet fixed in one wording, nature and practice. It is too early to say if the seemingly decreasing importance of the principle will be permanent, but it seems certain that the evolution of the regime through the Durban decisions has had a real influence on the conception of the principle and might lead to further changes from its past practice.

Even so, CBDR, as it has been defined in 1992, will remain an important achievement of the climate regime and, more, of international environmental law. It has been an efficient way to achieve the universality the regime needed and, somehow, it has allowed for the emergence of a more ethical conception of international law. Indeed, CBDR's primary aim has always been to provide more equitable and effective results within the system.107 For that, it should be kept as the basis of differentiated obligations. Only by underlining its function as an ethical basis for differentiated obligations can CBDR be used to its full effect, as no debate solely focused on CBDR will bring an answer to the degradation of the whole climate system. As the Copenhagen example shows, the absence of consensus on the principle and its implementation has been one of the main stumbling blocks in the negotiations. Still, the Durban decisions clearly show that this principle is not, in itself, a vital condition for the continuation of differential treatment in the regime. Therefore, a single-minded focus on debating CBDR brings certain risks with it. If parties remain so focused on the contents of the principle, they may end up in negotiating dead ends and forget the very purpose of the regime: fighting climate change – a purpose that needs universal cooperation. And the risk is real. When looking at the Cancún Agreements, one can see that even though a long-term temperature goal has been set, there is only a mention of a long-term global goal for emissions reduction. The setting of the latter had been postponed to Durban, but it was not set there either. Thus one will have to wait until Doha or beyond to hope for increased ambition in the fight against climate change.

While both changing and, to some extent, fading through the Durban decisions, it seems certain that the principle will never completely disappear from the climate negotiations and could again become one of the main stumbling blocks of the regime. Whatever may come in the future, CBDR will need to be carefully studied as it could have important implications for the entirety of international climate change law. At a time when the international community has to find adequate ways to tackle a potentially catastrophic environmental phenomenon, words attributed to Baldwin IV, leprous king of Jerusalem, come to mind: ‘[T]he survival of the realm of Jerusalem depends on the faith, the bravery and the caution of its king,’108 Although these words refer to the twelfth century, they resonate in the context of climate negotiations of the twenty-first century. Indeed, as often in international law, at the end of the day everything will come down to the result of political negotiations. Consequently, in shaping the future of climate law, everything will depend on the bravery and caution of parties as well as in their faith in the regime.

Thomas Deleuil is a PhD candidate and teaching assistant at the School of Law and Political Science of the University of Aix-Marseille, France. His research focuses on multilateral environmental agreements concerning climate change, the ozone layer, biodiversity, desertification, habitats and natural areas, waste and pollution. He has published on issues relating to international conservation law, international criminal law and climate change law, both in English and in French. These publications include a contribution to the 15th Conference on Environmental Assessment, Biodiversity and Environmental Assessment, Paris, 20–23 September 2010; a chapter in P. Farah (ed.), China's Influence on Non-trade Concerns in International Economic Law (Ashgate, 2012 forthcoming); and contributions (with S. Maljean-Dubois) to S. Maljean-Dubois and M. Wemaëre (eds), The International Negotiations of the Post-2012: A Legal Analysis of Core Issues – Final Report of the CERIC-IDDRI-University of Geneva Conference ‘Issues of the Future International Climate Regime Negotiations’, Paris, 26–27 January 2012.


  • 1

    See, e.g., F. Soltau, Fairness in International Climate Change Law and Policy (Cambridge University Press, 2009).

  • 2

    T. Honkonen, The Common but Differentiated Responsibility Principle in Multilateral Environmental Agreements: Regulatory and Policy Aspects (Kluwer Law International, 2009), at 2.

  • 3

    D. Shelton, ‘Equity’, in: D. Bodansky, J. Brunnée and E. Hey (eds), The Oxford Handbook of International Environmental Law (Oxford University Press, 2008), at 647.

  • 4

    Stockholm Declaration on the Human Environment, found in Report of the United Nations Conference on the Human Environment (UN Doc., A/CONF.48/14/Rev.1, 16 June 1972), Action Taken by the Conference (‘Stockholm Declaration’).

  • 5

    L. Rajamani, Differential Treatment in International Environmental Law (Oxford University Press, 2006), at 8.

  • 6

    L. Boisson de Chazournes, ‘Le Droit et l’Universalité de la Lutte contre les Changements Climatiques', 2 Journal Cahiers Droit, Sciences et Technologies: Droit et Climat (2009), 29, at 30 (my translation).

  • 7

    Rio Declaration on Environment and Development, found in Report of the UN Conference on Environment and Development (UN Doc. A/CONF.151/26/Rev.1 (Vol. I), 14 June 1992), Annex (‘Rio Declaration’).

  • 8

    United Nations Framework Convention on Climate Change (New York, 9 May 1992; in force 21 March 1994) (‘UNFCCC’).

  • 9

    Kyoto Protocol to the United Nations Framework Convention on Climate Change (Kyoto, 11 December 1997; in force 16 February 2005) (‘Kyoto Protocol’).

  • 10

    J. Lin, ‘Environmental Law and Policy in China: Responding to Climate Change’, in: G. Yu (ed.), The Development of the Chinese Legal System: Change and Challenges (Routledge, 2011), 295, at 296.

  • 11

    See L. Rajamani, n. 5 above, at 10.

  • 12

    UNFCCC, n. 8 above, preamble, paragraph 3.

  • 13

    E. Guerin and M. Wemaëre, Négociations Climat: Compte-rendu de la Conférence de Barcelone (2–6 Novembre 2009), IDDRI Idées pour le débat N°06/2009 (Institut du Développement Durable et des Relations Internationales, 2009), found at <>, at 10 (my translation).

  • 14

    Subsidiary Body for Scientific and Technological Advice (SBSTA), Views on Lessons Learned from the Mitigation Workshops Held to Date and on Future Work on Mitigation of Climate Change (UN Doc. FCCC/SBST A/2005/MISC.12, 17 August 2005), at 19.

  • 15

    Subsidiary Body for Implementation (SBI), Review of the Financial Mechanism Referred to in Decision 6/CP.13 (UN Doc. FCCC/SBI/2008/MISC. 3, 19 May 2008), at 27.

  • 16

    Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol (AWG-KP), Views on the Legal Implications Arising from the Work of the Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol, Pursuant to Article 3, paragraph 9, of the Kyoto Protocol (UN Doc. FCCC/KP/AWG/2009/MISC.6/Add.2, 26 March 2009), at 3.

  • 17

    Subsidiary Body for Implementation (SBI), Views on Elements for the Terms of Reference for the Review and Assessment of the Effectiveness of the Implementation of Article 4, paragraphs 1(c) and 5, of the Convention (UN Doc. FCCC/SBI/2008/MISC.1, 17 March 2008), at 4.

  • 18

    Ibid., at 10.

  • 19

    AWG-KP, Further Views and Proposals Relating to a Proposal for Amendments to the Kyoto Protocol pursuant to its Article 3, paragraph 9, and a Text on Other Issues Outlined in Document FCCC/KP/AWG/2008/8 (UN Doc FCCC/KP/AWG/2009/MISC.8, 6 May 2009), at 45.

  • 20

    D. Bodansky, ‘The Copenhagen Climate Change Conference: A Postmortem’, 104:2 American Journal of International Law (2010), 230, at 231–232.

  • 21

    The Copenhagen Accord is attached to Decision 2/CP.15, Copenhagen Accord (UN Doc. FCCC/CP/2009/11/Add.1, 30 March 2010). It was only ‘taken note of’ by the COP and still does not have any formal legal status.

  • 22

    L. Rajamani, ‘The Making and Unmaking of the Copenhagen Accord’, 59:3 International and Comparative Law Quarterly (2011), 824, at 842.

  • 23

    L. Rajamani, ‘The Cancún Climate Agreements: Reading the Text, Subtext and Tea Leaves’, 60:2 International and Comparative Law Quarterly (2011), 499, at 519.

  • 24

    Decision 1/CP.16, The Cancún Agreements: Outcome of the Work of the Ad Hoc Working Group on Long-term Cooperative Action under the Convention (UN Doc. FCCC/CP/2010/7/Add.1, 15 March 2011), Parts III and V.

  • 25

    See L. Rajamani, n. 23 above, at 512.

  • 26

    Decision 1/CP.17 Establishment of an Ad Hoc Working Group on the Durban Platform for Enhanced Action (UN Doc. FCCC/CP/2011/9/Add.1, 15 March 2012), paragraph 2.

  • 27

    Decision 2/CP.17, Outcome of the Work of the Ad Hoc Working Group on Long-term Cooperative Action under the Convention (UN Doc. FCCC/CP/2011/9/Add.1, 15 March 2012).

  • 28

    Decision 1/CP.13, Bali Action Plan (UN Doc. FCCC/CP/2007/6/Add.1, 14 March 2008).

  • 29

    See Decision 1/CP.1, Berlin Mandate (UN Doc. FCCC/CP/1995/7/Add.1, 6 June 1995); the Kyoto Protocol, n. 9 above; Decision 1/CP.8, Delhi Ministerial Declaration on Climate Change and Sustainable Development (UN Doc. FCCC/CP/2002/7/Add.1, 28 March 2003); Decision 1/CP.13, Bali Action Plan, n. 28 above; Decision 2/CP.15, Copenhagen Accord, n. 21 above; and Decision 1/CP.16, The Cancún Agreements, n. 24 above.

  • 30

    Decision 2/CP.17, Outcome of the Work of the Ad Hoc Working Group, n. 27 above, at paragraphs 8, 10, 17, 18 and 28.

  • 31

    Decision 3/CP.17, Launching the Green Climate Fund (UN Doc. FCCC/CP/2011/9/Add.1, 15 March 2012), paragraph 4 and Annex.

  • 32

    UNFCCC, n. 8 above, preamble, paragraph 6.

  • 33

    Ibid., Article 4.

  • 34

    Subsidiary Body for Implementation (SBI), Report on Inter-Sessional Activities: Work of the Consultative Group of Experts on National Communications from Parties not Included in Annex 1 to the Convention (UN Doc. FCCC/SBI/2001/INF.1, 28 June 2001), at 17.

  • 35

    Subsidiary Body for Scientific and Technological Advice (SBSTA), Information on Experiences and Views on Needs for Technical and Institutional Capacity-Building and Cooperation (UN Doc. FCCC/SBSTA/2009/MISC.2, 10 March 2009), at 22.

  • 36

    Subsidiary Body for Scientific and Technological Advice (SBSTA), Views on Outstanding Methodological Issues Related to Policy Approaches and Positive Incentives to Reduce Emissions from Deforestation and Forest Degradation in Developing Countries (UN Doc. FCCC/SBSTA/2008/MISC.4, 22 April 2008), at 24.

  • 37

    Statute of the International Court of Justice (San Francisco, 26 June 1945; in force 24 October 1945).

  • 38

    The advisory opinion given by the International Tribunal on the Law of the Sea (ITLOS) on the Case No. 17 on 1 February 2011 addresses the question of differential treatment within the Montego Bay Convention but does not refer to CBDR as such. See ITLOS 1 February 2011, Responsibilities and Obligations of States Sponsoring Persons and Entities with Respect to Activities in the Area (Request for Advisory Opinion submitted to the Seabed Disputes Chamber), paragraphs 151–162, found at <>. The WTO Panel quoted CBDR in the Shrimp/Turtle case, but only in reference to the Rio Declaration, which is not legally binding. United States – Import Prohibition of Certain Shrimp and Shrimp Products, Recourse to Article 21.5 by Malaysia, Report of the Panel, 15 June 2001, WT/DS58/RW, at 101.

  • 39

    E. Brown Weiss, ‘The Rise and Fall of International Law?’, 69:2 Fordham Law Review (2000), 345, at 350.

  • 40

    P. Birnie, A. Boyle and C. Redgwell, International Law and the Environment, 3rd edn (Oxford University Press, 2009), at 135.

  • 41

    S. Biniaz, ‘Common but Differentiated Responsibility’, 96 ASIL Proceedings (2002), 358, at 361.

  • 42

    ICJ 27 June 1986, Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), [1986] ICJ Rep. 14, at 108–109.

  • 43

    See L. Rajamani, n. 5 above, at 159.

  • 44

    Subsidiary Body for Implementation (SBI), Procedures and Mechanisms relating to Compliance under the Kyoto Protocol (UN Doc. FCCC/SB/1999/MISC.12, 22 September 1999), at 15.

  • 45

    See the submission by Peru, on behalf of Colombia, Costa Rica, Ecuador, Mexico, Nicaragua, Panama and Peru, in Subsidiary Body for Implementation (SBI), Issues Relating to Reducing Emissions from Deforestation in Developing Countries and Recommendations on Any Further Process (FCCC/SBSTA/2006/MISC.5, 11 April 2006), at 111.

  • 46

    SBI, n. 44 above, at 4.

  • 47

    See T. Honkonen, n. 2 above, at 303–304.

  • 48

    See also U. Beyerlin, ‘Policies, Principles and Rules’, in: D. Bodansky, J. Brunnée and E. Hey, n. 3 above, at 442.

  • 49

    P.-M. Dupuy and Yann Kerbrat, Droit International Public, 10th edn (Dalloz, 2010), at 376.

  • 50


  • 51

    A. Boyle and C. Chinkin, The Making of International Law (Oxford University Press, 2007), at 224.

  • 52

    PCIJ 17 August 1923, Wimbledon Case (Ser. A., No. 1, 1923); ICJ 28 May 1951, Reservations to the Convention on the Prevention and Punishment of the Crime of Genocide, Advisory Opinion, [1951] ICJ Rep. 1951, 3, at 21.

  • 53

    Ibid.; see also PCIJ 7 June 1932, Case of the Free Zones of Upper Savoy and the District of Gex (Ser. A/B., No. 46), at 167.

  • 54

    Arbitral Tribunal 24 May 2005, Arbitration regarding the Iron Rhine (‘Ijzeren Rijn’) Railway (2005), at paragraph 59.

  • 55

    In Decision 1/CP.16, one reference to differentiation is not expressed through CBDRRC but through ‘common but differentiated responsibilities and respective capabilities, and specific national and regional development priorities, objectives and circumstances’. Decision 1/CP, 16 n. 24 above, paragraph 14.

  • 56


  • 57

    Decision 2/CP.17, n. 30 above, Part II.E, preamble, paragraph 1.

  • 58

    Ibid., Part II.E, preamble, paragraph 2.

  • 59

    Ibid., paragraph 160.

  • 60

    Decision 3/CP.17, n. 31 above, paragraph 4.

  • 61

    P. Sands, Principles of International Environmental Law, 2nd edn (Cambridge University Press, 2003), at 289.

  • 62

    See especially L. Boisson de Chazournes and S. Maljean-Dubois, Principes du Droit International de l'Environnement, Journal JurisClasseur Environnement et Développement Durable (2010).

  • 63

    Decision 7/CP.4, Work Programme on Mechanisms of the Kyoto Protocol (UN Doc. FCCC/CP/1998/16/Add.1, 25 January 1999), preamble paragraph 1; Decision 1/CP.6, Implementation of the Buenos Aires Plan of Action (UN Doc. FCCC/CP/2000/5/Add.2, 4 April 2001), preamble, paragraph 1; Decision 5/CP.7, Implementation of Article 4, paragraphs 8 and 9, of the Convention (UN Doc. FCCC/CP/2001/13/Add.1, 21 January 2002), preamble, paragraph 7; Decision 26/CP.7, Amendment to the List in Annex II to the Convention (UN Doc. FCCC/CP/2001/13/Add.4, 21 January 2002), preamble, paragraph 7; Decision 1/CP.8, n. 29 above, preamble, paragraph 8(d).

  • 64

    SBI, n. 15 above, at 22.

  • 65

    See Decision 6/CP.8, Additional Guidance to an Operating Entity of the Financial Mechanism (UN Doc. FCCC/CP/2002/7/Add.1, 28 March 2003), preamble, paragraph 1; Decision 11/CP.8, New Delhi Work Programme on Article 6 of the Convention (UN Doc. FCCC/CP/2002/7/Add.1, 28 March 2003), preamble, paragraph 1; Decision 4/CP.9, Additional Guidance to an Operating Entity of the Financial Mechanism (UN Doc. FCCC/CP/2003/6/Add.1, 22 April 2004), preamble, paragraph 1; Decision 1/CP.11, Dialogue on Long-term Cooperative Action to Address Climate Change by Enhancing Implementation of the Convention (UN Doc. FCCC/CP/2005/5/Add.1, 30 March 2006), preamble, paragraph 1; Decision 5/CP.11, Additional Guidance to an Operating Entity of the Financial Mechanism (UN Doc. FCCC/CP/2005/5/Add.1, 30 March 2006), preamble, paragraph 1; Decision 9/CP.11, Research Needs Relating to the Convention (UN Doc. FCCC/CP/2005/5/Add.1, 30 March 2006), preamble, paragraph 2; Decision 2/CP.13, Reducing Emissions from Deforestation in Developing Countries: Approaches to Stimulate Action (UN Doc. FCCC/CP/2007/6/Add.1, 14 March 2008), preamble, paragraph 1; Decision 7/CP.13, Additional Guidance to the Global Environment Facility (UN Doc. FCCC/CP/2007/6/Add.1, 14 March 2008), preamble, paragraph 1; Decision 9/CP.13, Amended New Delhi Work Programme on Article 6 of the Convention (UN Doc. FCCC/CP/2007/6/Add.1, 14 March 2008), preamble, paragraph 1; Decision 4/CP.14, Additional Guidance to the Global Environment Facility (UN Doc. FCCC/CP/2008/7/Add.1, 18 March 2009), preamble, paragraph 1; Decision 1/CP.16, n. 24 above, preamble, paragraph 4; Part E preamble, paragraph 1; and paragraph 89.

  • 66

    Vienna Convention on the Law of Treaties (Vienna, 23 May 1969; in force 27 January 1980). See P. Birnie, A. Boyle and C. Redgwell, n. 40, at 28.

  • 67

    The principle of prevention is derived from Principle 11 of the Rio Declaration, n. 7 above. It involves the implementation of rules and actions to anticipate risks of environmental degradation, taking into account the latest technical progress. As opposed to the precautionary principle, prevention only concerns proven risks. See J. Verhoeven, ‘Principe de Précaution, Droit International et Relations Internationales’, 3 Annuaire Français des Relations Internationales (2002), 250, at 252. The ICJ referred to prevention in the 1997 Gabčikovo-Nagymaros case. See ICJ 25 September 1997, Gabčikovo-Nagymaros Project (Hungary v. Slovakia),[1997] ICJ Rep. 7, at 77.

  • 68

    Arbitral Tribunal 24 May 2005, Arbitration Regarding the Iron Rhine Railway, n. 63 above.

  • 69

    In addition to P. Birnie, A. Boyle and C. Redgwell, n. 40 above, and L. Rajamani, n. 5 above, see P. Cullet, ‘Differential Treatment in International Law: Towards a New Paradigm of Inter-state Relations’, 10:3 European Journal of International Law (1999), 549, at 579; and C.D. Stone, ‘Common but Differentiated Responsibilities in International Law’, 98:2 American Journal of International Law (2004), 276, at 281.

  • 70

    See especially the Decision 2/CP.17, n. 27 above.

  • 71

    Decision 1/CP.17, n. 26 above.

  • 72

    Ibid., paragraph 2.

  • 73

    Ibid., paragraphs 2 and 4.

  • 74

    L. Rajamani, ‘The Durban Platform for Enhanced Action and the Future of the Climate Regime’, 61:2 International and Comparative Law Quarterly (2012), 501, at 508.

  • 75


  • 76


  • 77

    Convention on Biological Diversity (Rio de Janeiro, 5 June 1992; in force 29 December 1993), Article 6.

  • 78

    United Nations Convention to Combat Desertification (Paris, 17 June 1994; in force 26 December 1996), Article 3d.

  • 79

    Vienna Convention for the Protection of the Ozone Layer (Vienna, 22 March 1985; in force 22 September 1988).

  • 80

    Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal, 16 September 1987; in force 1 January 1989).

  • 81

    See inter alia, Decision IV/4, Further Amendment of the Protocol (UN Doc. UNEP/OzL.Pro.4/15, 25 November 1992), paragraph 68; Report of the Seventh Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (UN Doc. UNEP/OzL.Pro.7/12, 27 December 1995), paragraph 4; Report of the Eighth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (UN Doc. UNEP/OzL.Pro.8/12, 19 December 1996), paragraph 37; Report of the Eighth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (UN Doc. UNEP/OzL.Pro.9/12, 25 September 1997), paragraph 5; Decision XVI/7, Trade in Products and Commodities Treated with Methyl Bromide (UN Doc. UNEP/OzL.Pro.16/17, 16 December 2004), preamble, paragraph 3; Report of the Eighteenth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (UN Doc. UNEP/OzL.Pro.18/10, 16 November 2006), paragraphs 163, 165 and 167; Report of the Nineteenth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (UN Doc. UNEP/OzL.Pro.19/7, 21 September 2007), paragraphs 45 and 84; Decision XIX/31, Declaration of Montreal (UN Doc. UNEP/OzL.Pro.19/7, 21 Sept. 2007), Annex.

  • 82

    Decision 2/CP.17, n. 27 above.

  • 83

    Decision 1/CP.16, n. 24 above, paragraph 44.

  • 84

    Ibid., paragraphs 63–64.

  • 85

    Ibid. This division is in line with the 2007 Bali Action Plan. Decision 1/CP.13, n. 28 above, paragraph 1(b)(i) and (ii).

  • 86

    Decision 2/CP.17, n. 27 above, Part II.B, preamble, paragraph 5.

  • 87

    UNFCCC, n. 8 above, Article 4.7.

  • 88

    Decision 1/CP.17, n. 26 above, paragraph 58(b).

  • 89

    Decision 2/CP.17, n. 27 above, Part II.B, preamble, paragraphs 6 and 87.

  • 90

    Ibid., Part IV.

  • 91

    Ibid., Part V.

  • 92

    Ibid., Part VI.

  • 93

    Ibid., Part II.B, preamble.

  • 94

    Ibid., Part II.B, paragraph 41(a).

  • 95

    Ibid., Part II.B, paragraph 57.

  • 96

    UNFCCC, n. 8 above, Article 2.

  • 97

    Stockholm Declaration, n. 4 above, Principle 1; Rio Declaration, n. 7 above, Principle 3.

  • 98

    AWG-KP, Information and Data Related to Paragraph 17 (a) (i) and (ii) of Document FCCC/KP/AWG/2006/4 and to the Scale of Emission Reductions by Annex I Parties, and Views on the Organization of an In-session Workshop on These Issues (UN Doc. FCCC/KP/AWG/2008/MISC.4/Add.1, 28 November 2008), at 6.

  • 99

    AWG-KP, Consideration of the Scale of Emission Reductions to be Achieved by Annex I Parties in Aggregate, of the Contribution of Annex I Parties Individually or Jointly, Consistent with Article 4 of the Kyoto Protocol, to the Scale of Emission Reductions to be Achieved by Annex I Parties in Aggregate, and of Other Relevant Issues Arising from the Implementation of the Work Programme of the Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol as Contained in Document FCCC/KP/AWG/2008/8, Paragraph 49(c) (UN Doc. FCCC/KP/AWG/2009/MISC.1, 12 March 2009), at 17.

  • 100

    See L. Rajamani, n. 23 above, at 512.

  • 101

    V. Heyvaert, ‘Levelling Down, Levelling Up and Governing Across: Three Responses to Hybridization in International Law’, 20:3 European Journal of International Law ((2009), at 647.

  • 102

    See L. Rajamani, n. 23 above, at 512.

  • 103

    See the overview of contributions to fast-start finance (total pledged and total committed), found at: <>.

  • 104

    S. Maljean-Dubois and M. Wemaëre, Les Enjeux des Négociations du Futur Régime International du Climat (2012), found at: <>, at 27.

  • 105

    United Nations Environment Programme (UNEP), Global Environment Outlook 5: Environment for the Future We Want (UNEP, 2012), found at: <>, at 39. See also L. Rajamani, n. 74 above, at 502.

  • 106

    UNFCCC, n. 8 above, Article 2.

  • 107

    P. Cullet, Differential Treatment in International Environmental Law (Ashgate, 2003), at 15.

  • 108

    Unfortunately, the quotation remains uncertain. These words could be those of William of Tyre, Baldwin's tutor and historian of crusades. See, e.g., P. Aube, Baudouin IV de Jérusalem: Le Roi Lépreux (Perrin, 2001); R. Grousset, Histoire des Croisades et du Royaume Franc de Jérusalem (Perrin, 1999).