1. A CORE ISSUE
A statement by the European Union (EU) leads directly to one of the toughest problems in the international climate change regime:
Under the [United Nations Framework Convention on Climate Change (UNFCCC)Footnote 1], the EU and its Member States have taken a joint emission reduction target to reduce its [greenhouse gas (GHG)] emissions by at least 20% compared to 1990 by 2020, with a conditional offer to move to a 30% reduction, provided that other developed countries commit themselves to comparable emission reductions and developing countries contribute adequately according to their responsibilities and respective capabilities.Footnote 2
This policy position, reiterated many times by the EU, might seem unremarkable, yet it states an untruth, and aspects of it verge on the meaningless. In March 2018, I was at the European Commission's Directorate-General for Climate Action (DG CLIMA) in Brussels (Belgium) as a member of an Expert Review Team dispatched to carry out the ‘in-country’ review of the EU's Seventh National Communication and Third Biennial Report under the UNFCCC. I asked the EU representatives at the meeting about the EU's ‘conditional offer’, and was told that no process exists to trigger it and that none had ever existed. In other words, no conditional offer was ever on the table.Footnote 3
Untruthfulness is only one of the problems with this passage. Some of the terms it deploys – ‘comparable emission reductions’ (for developed countries) and ‘contribute adequately’ (for developing countries) – are themselves so vague as to be almost meaningless. Neither developed nor developing countries could have known what they needed to do to meet the ‘condition’ for the EU to move from a 20% to a 30% mitigation target. Also, what sense can we make of the EU's stance in seeming to require other countries to act first, before it itself will act? Indeed, none of this makes much sense, so the passage must be understood as saying something different from what it seems to be saying. What it really means to say, I would suggest, is this: ‘We, in the EU, could do more if other states would only do more, too. How are we to break this deadlock?’
It is a question left hanging. The Paris AgreementFootnote 4 made the task of answering it a little easier, for now there is a treaty-inscribed ceiling of 2°C (degrees Celsius) on global warming, which implies that there is a ‘budget’ for the remaining allowable emissions before the world must achieve carbon neutrality. There are considerable uncertainties associated with this budget, but even an uncertain budget is preferable to no budget at all, particularly when it comes to answering the EU's question about how to rationalize the mitigation effort of states. Nevertheless, the Paris Agreement stops short of incorporating another element needed to answer the EU's question – namely, the rules or procedures for allocating the ‘below 2°C’ budget fairly among states.
In this article, I explain first (Section 2) the distinction between individual and collective state obligations. I contend that legal scholars have either missed the distinction between these obligations entirely, or have acknowledged it only superficially. I then clarify the textual basis for the collective obligation that appears to exist in the Paris Agreement. Following this, Section 3 examines the international legal precedent for a collective obligation. I find that there is no theoretical reason why such an obligation should not subsist in the Paris Agreement in a legally binding form. However, that kind of obligation would be of a new and consequential nature and, as such, could not be read into the 2015 treaty without clear language to give it effect. I then argue, in Section 4, that if the Agreement's apparent collective obligation – even if not legally binding – is to be complied with by states, the nationally determined contributions (NDCs) of states must be adjusted equitably through a collective process. I consider, in Section 5, the characteristics of such a process and how it might be put into practice. I conclude by arguing that, at present, no existing treaty element has the ability to facilitate this role, with the possible exception of the Paris Agreement's global stocktake.
2. A FORM OF COLLECTIVE OBLIGATION IN THE PARIS AGREEMENT?
This section distinguishes between two types of obligation in the Paris Agreement, with the aim of demonstrating that the distinction has been overlooked – or only superficially noted – in the scholarly literature to date. It also introduces some new terminology. ‘Ambition’, ‘effort’, ‘fair share’, and cognate concepts can be ambiguous in the context of the climate change regime, where the value of a state's contribution can be apprehended only in comparison with the contributions of other states. To avoid ambiguity, I will use two technical terms to replace the ambiguous term ‘ambition’. I define these terms – ‘S-ambition’ and ‘T-ambition’– below. For the purposes of this article, I consider that the term ‘effort’ is synonymous with ‘ambition’, and the notion of ‘fair share’ is incorporated into the idea of T-ambition. I will also use another new term, ‘individuation mechanism’, to denote a process or mechanism that facilitates the reduction of a collective state obligation to individual state obligations.
2.1. Collective and Individual Obligations in the Paris Agreement
The Paris Agreement appears to create obligations for states in each of two categories: ‘individual’– that is, state-level – and ‘collective’. While much legal commentary has sought to clarify the legal content of the Paris Agreement (see Section 2.2 below), no work has so far elaborated on the fact that the treaty's obligations for states fall within either individual or collective obligations. In the following, I review the individual state obligations before analyzing the evidence for a collective obligation.
The important individual obligations for states created by the Paris Agreement are dealt with in several provisions. I begin with two articles. The first is Article 4.2, which states that ‘[e]ach Party shall prepare, communicate and maintain successive nationally determined contributions that it intends to achieve’. The second is Article 4.3, according to which ‘[e]ach Party's successive nationally determined contribution will represent a progression beyond the Party's then current nationally determined contribution and reflect its highest possible ambition’.
The latter article employs the notion of mitigation ‘ambition’ in a sense that I will refer to as ‘S-ambition’– short for ‘state ambition’. S-ambition – the definition of which I will come to shortly – is to be distinguished from the mitigation ambition that each state party to the treaty would need to exhibit in order for the parties collectively to ensure that the average global temperature increase remains within 2°C, as set out in the Agreement. I will refer to the latter form of ambition as ‘T-ambition’ – short for ‘treaty ambition’. T-ambition and S-ambition may coexist at the state level. However, as I will show later, the most common situation is for states to display no T-ambition at all, but only the simpler S-ambition.
I now come to the definition of S-ambition, and in the process of defining it I will use the term ‘containment outcome’ as shorthand for the treaty-inscribed 2°C ceiling on global warming. S-ambition may be defined as the mitigation target (or the sum of mitigation targets where a state uses multiple complementary targets) that a state sets for itself without any reasoned consideration and affirmative decision that the target represents a fair effort in a global context, such that it would deliver the aforementioned containment outcome in a situation where all other states were also making a fair effort and committing themselves to corresponding targets. Straightforward examples of S-ambition are (i) the EU's 20% mitigation target for 2020, referred to in my opening paragraph, which makes no claim to being anything other than a target that the EU happens to find suitable in its own developmental context; and (ii) China's actions for the period through to 2020, described by that state as ‘voluntary actions taken by China according to its national circumstances’.Footnote 5
A number of other articles in the Paris Agreement create individual state obligations. These include Article 4.9, which declares that ‘[e]ach Party shall communicate a nationally determined contribution every five years’. Further, Article 4.11 provides that any party ‘may at any time adjust its existing nationally determined contribution with a view to enhancing its level of ambition’. In fact, this entitlement, rather than obligation, may be construed as either S-ambition or T-ambition, depending on the rationale for the adjustment. The requirement in Article 4.13 for parties to ‘account for’ their NDCs appears to obligate them to report accurately on their emissions. This topic is taken up in Article 13.7, which states that ‘[e]ach Party shall regularly provide … (a) A national inventory report of anthropogenic emissions by sources and removals by sinks … and (b) Information necessary to track progress made in implementing and achieving its nationally determined contribution’.
As may be seen from this group of provisions, the individual obligations in the Paris Agreement are procedural in nature.Footnote 6 They address the subject matter, frequency, and method of amendment of what are, in effect, different types of formal declaration by state parties to the Agreement – namely, formal declarations on GHG emission levels (called national inventory reports under the Kyoto ProtocolFootnote 7), mitigation targets and other promised actions in the future (the NDCs), and progress reports on NDC implementation (biennial transparency reports).Footnote 8 The main aim of these individual obligations is to achieve transparency in state action. While the provisions in this class also include references to state ‘ambition’, which is a substantive and not merely a procedural concept, they dictate only that a state is to declare its ambition, and then only what I am calling its S-ambition. The term ‘highest possible ambition’ in Article 4.3 of the Paris Agreement denotes whichever ambition a state decides for itself is its highest possible ambition: the treaty does not define this term and does not provide for any process to reveal, rationalize, debate, standardize, or otherwise inform the determination of a state's ambition. I address this further in Section 5.
Just as interesting as the state-level obligations is what the Paris Agreement has to say about collective obligation. Indeed, it is the treaty's apparent creation of a collective obligation that gives the Paris Agreement its unique character as an agreement on the incomparable and indivisibly global problem of climate change.
The special context of the Agreement is set by its Preamble, which acknowledges that ‘climate change is a common concern of humankind’. This context is unique to the climate change regime, and is distinguishable from the ‘common concern’ expressed in other multilateral environmental agreements.Footnote 9 The central element of the Paris Agreement's collective obligation is contained in Article 2.1:
This Agreement … aims to strengthen the global response to the threat of climate change … including by: (a) Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.
Indicators of legal obligation – the use of the modal verb ‘shall’, for example, applied to a subject of the obligation – are absent from the formulation of Article 2.1. They are, however, implied into Article 2.1 by other elements of the Agreement. Consider, for example, the obligation under Article 3: ‘As nationally determined contributions to the global response to climate change, all Parties are to undertake and communicate ambitious efforts … with the view to achieving the purpose of this Agreement as set out in Article 2.Footnote 10
The phrase ‘all Parties are to’ is equivalent to ‘all parties shall’. That all parties are to ‘undertake … ambitious efforts’ is therefore mandatory. Such efforts are not merely to be nationally determined (or S-ambition efforts); they are also to be determined ‘with the view to achieving the purpose of this Agreement as set out in Article 2’. The ‘ambition’ to which Article 3 refers is an instance of T-ambition, for it is tied to the containment of global warming within the 2°C limit. This ambition is distinguishable from Article 4.3's inward-looking, solipsistic ‘highest possible ambition’ of a state.
Under Article 4.2, the submission of an NDC is mandatory for each party, and Article 3 provides that the NDC aggregate ambition must achieve the purpose of the Agreement. Since Article 2.1 expresses the Agreement's purpose, it follows that achieving the purpose of Article 2.1 is also mandatory, notwithstanding the legally neutral wording of Article 2.1 when read in isolation. The below 2°C containment obligation is mandatory not for any one state or group of states, of course; it is mandatory for the state parties collectively. This straightforward logical implication of the Paris Agreement does not seem to have been noticed before, despite its potentially profound consequences.
Article 2.1 of the Paris Agreement should be interpreted in the context of Article 2 of the UNFCCC. This is because the Preamble to the Paris Agreement requires ‘[t]he Parties to [the Paris] Agreement [to act] in pursuit of the objective of the Convention’. What is the Convention's objective? Article 2 UNFCCC defines the parties’ ‘ultimate objective’ as ‘stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system’. This objective is given specificity in Article 2.1 of the Paris Agreement, in which compliance with the global 2°C temperature goal is made mandatory, as my above interpretation of the text has demonstrated.
It follows from the above considerations that the Paris Agreement is not merely an assemblage of procedural obligations, as some have claimed,Footnote 11 but also contains a strong substantive obligation. The latter exists at the collective rather than the individual state level.Footnote 12
Another element of the idea of a collective obligation is contained in Article 3 of the Paris Agreement: ‘The efforts of all Parties will represent a progression over time’. Assuming that this is not merely duplicative of the individual progression requirement of Article 4.3, which I quoted above, the article requires that the efforts of all parties – acting together – ‘will’ become progressively stronger. Another version of the collective-progress requirement is found in Article 4.1:
In order to achieve the long-term temperature goal set out in Article 2, Parties aim to reach global peaking of greenhouse gas emissions as soon as possible … and to undertake rapid reductions thereafter … so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century.
In light of my argument above that the achievement of ‘the long-term temperature goal set out in Article 2’ is mandatory, it follows that the ‘aim’ to reach ‘global peaking’ as soon as possible is also mandatory. This is because we know from scientific accounts that any significant delay in the achievement of global peaking would make containment of the temperature rise within the 2°C limit practically impossible.Footnote 13 It follows, as a matter of legal as well as factual necessity, that no significant delay in the collective effort of parties is allowable.
The Paris Agreement's provisions on international mitigation finance also suggest that there is a collective obligation on the parties to the Agreement to realize the below 2°C containment outcome. The relevant part of Article 2.1 is, at first sight, legally non-committal on finance: ‘This Agreement … aims to strengthen the global response to the threat of climate change … including by: … (c) Making finance flows consistent with a pathway towards low greenhouse gas emissions and climate-resilient development’.
Once again, this must be interpreted in context. Article 4.5, another provision that suggests the existence of a collective obligation, clarifies that financial support is mandatory: ‘Support shall be provided to developing country Parties for the implementation of this Article … recognizing that enhanced support for developing country Parties will allow for higher ambition in their actions’. This identical obligation is reiterated in Article 9.1. The collective of states responsible for the performance of the Article 4.5 obligation is not – as might seem at first from the language used – the developed country parties alone. This would make no sense, for there can be no obligation, in this context, to give without a mirror obligation to receive (and to implement). The international scheme for climate finance, insofar as it goes beyond a mere obligation to offer, is necessarily constituted of the obligation to supply finance and to make use of it for mitigation (as well as for adaptation).
A plain reading of the Paris Agreement's provisions on climate finance is thus that the treaty sets up an all-party collective obligation, to the effect that those in a position to supply finance must do so, whereas those receiving finance must use it to enhance their mitigation effort. The amount of climate finance to be supplied and used is not free-floating but is to be determined in the context of the 2°C warming limit set by Article 2.1. The textual basis for this is not the treaty text itself but the Conference of the Parties’ (COP) decision adopting the treaty:
[The COP] [d]ecides that … financial resources provided to developing country Parties should enhance the implementation of their … climate change actions with respect to both mitigation and adaptation to contribute to the achievement of the purpose of the Agreement as defined in its Article 2.Footnote 14
Climate finance must promote the attainment of the below 2°C outcome. It follows that a country's ambition on (the provision or use of) climate finance must not only be S-ambition; it must be T-ambition. That is, it must be in fulfilment of the collective obligation on climate finance, understood as serving the aim of Article 2.1. The climate-finance obligation is thus one aspect of the collective obligation anchored in Article 2.1.
Having thus laid out the evidence of a collective obligation that subsists in the Paris Agreement, I will proceed to consider how this form of obligation has been reflected in legal scholarship.
2.2. Commentary on the Paris Agreement's Collective Obligation
Legal commentary on the Paris Agreement can generally be categorized as works that recognize a collective obligation (or set of collective obligations) in the treaty,Footnote 15 and those that do not mention any such obligation.Footnote 16 There are also a few cases where an author acknowledges the existence of a collective obligation in the Agreement in one work, but not in another.Footnote 17 I am not aware of any scholar who positively denies that there is a collective obligation expressed in the Paris Agreement.
Thus, the notion that one or more obligations exist at the ‘collective’ level in the Paris Agreement already has some currency in the writings that explicitly mention this kind of obligation, or those that reference it by implied contrast when underscoring the existence of individual state obligations.Footnote 18 In none of these cases of positive or implied recognition, however, has any author provided an explanation of what a collective obligation is. It rather seems to be presumed either that the reader is aware of this category of obligation, or that its meaning is so obvious that no clarification is needed. The presumption is unjustified. The climate law literature does not contain any relevant prior discussion of this topic.
The position one takes on whether a collective obligation subsists in the Paris Agreement significantly affects one's understanding of what the Agreement is about. I will illustrate this with a contrast between Mayer's position and my own. Mayer claims that the key obligation ‘with regard to climate change mitigation is to be found in the second sentence of Article 4(2)’Footnote 19 – namely that ‘Parties shall pursue domestic mitigation measures, with the aim of achieving the objectives of such [nationally determined] contributions’. This is an obligation of the individual kind. It is purely procedural; it can be satisfied without achieving any mitigation outcome at all. While Mayer might prefer to call this an obligation of conduct or due diligence, it is still only procedural, as it does not require any actual mitigation. Thus, from Mayer's perspective, the point of the Paris Agreement is to create and coordinate multiple individual state procedural obligations. By contrast, on my analysis, the key treaty obligation, at least prima facie, is found earlier, in the first sentence of Article 3:
As nationally determined contributions to the global response to climate change, all Parties are to undertake and communicate ambitious efforts as defined in Articles 4, 7, 9, 10, 11 and 13 with the view to achieving the purpose of this Agreement as set out in Article 2.
This obligatory (‘are to’) provision incorporates the whole of Article 4, as well as other articles containing individual obligations, and moreover states that NDCs must be ‘ambitious’ enough to meet the Article 2.1 mitigation objective (T-ambition). From my perspective, then, the point of the Paris Agreement as a matter of strict textual interpretation is to create and coordinate a collective state substantive obligation, namely, to stay inside the 2°C limit. Whether the strict textual interpretation survives a broader legal interpretation is a question to which I return below.
3. LEGAL CHARACTER OF THE COLLECTIVE OBLIGATION
What are the properties of a collective obligation of the kind subsisting in the Paris Agreement, and to what extent do they correspond with those of collective obligations that have been described to date in international law?
3.1. Entailments of the Obligation
I have argued that the Paris Agreement appears to set up an obligation that all state parties acting together must not allow the global average temperature to reach 2°C above pre-industrial levels. If this were a genuine legal obligation, it would mean that the collective obligation to contain global warming to a level below 2°C is held by the community of states (parties) as a whole and owed to the community of states (parties) as a whole.Footnote 20 Put simply, the community of states would be the subject of an obligation it owes to itself. What could that mean?
Where a complex entity – such as a state (as opposed to an individual person) – is involved, self-referential or reflexive obligations are not as outlandish as they might seem. States can, in their domestic laws, limit their own behaviour in all sorts of ways with respect to themselves. Several states have done just that in the context of climate change. The United Kingdom (UK), for example, has passed legislation to make its emission reduction targets and budgets legally binding at the domestic level.Footnote 21 It has thereby bound itself to an obligation it owes to no other state (it being a domestic matter) but itself, and it is no less a legal obligation for being ‘unilateral’.Footnote 22 China has done the same in relation to its domestic emission-intensity target, although not through legislation but through other legal means specific to that country.Footnote 23 It has obligated itself (legally) to meet this self-imposed target. Because no Chinese citizen could sue the government for failing to comply with the target, it is an example of an obligation that, while having the status of law, is unenforceable.
If this kind of arrangement is not unusual at the state level, there is nothing implausible about a group of states settling on a similar arrangement at the global level – namely, by coalescing into a kind of ‘legal person’Footnote 24 which binds itself to a legal obligation it owes to no-one but itself. The existence of a new global organization, or government, is not essential for such an arrangement. The legal personality subsists in a community of states. The state collective is capable of acting jointly (such as through its annual conferences under the Paris Agreement) to fulfil its obligation. It is not a ‘super-state’ but operates through the ‘concurrent action’ of states.Footnote 25
The second entailment concerns the legal consequence of failing to meet a collective obligation of this kind. Failure to achieve the Paris Agreement outcome of below 2°C containment would amount to the state parties to the Agreement being collectively in breach of their collective obligation. What liability does that entail?
The legal exposure could be significant. Because of the solemnity of a legal obligation and the inherent complexity of states (which consist of thinking, and in most cases voting, people), a community of states that breaches its legal obligation, if only towards itself, will suffer negative reputational consequences that are likely to call into question the notion of an ‘international community’, international law, and of course the climate change regime itself. These undesirable consequences can easily be imagined and need not detain us here. (Compare this situation with that of China, where the price of government failure is political embarrassment, which is a hefty price to pay, even in a country that is not a liberal democracy.) For the purposes of my argument, it is sufficient to allow that the cost of a breach of the Paris Agreement's collective obligation might be appreciable. The fact that the obligation is non-actionable (in a court of law) does not necessarily make it a non-obligation.Footnote 26
The collective obligation which appears in the Paris Agreement not only accords well with the attitude we expect a climate treaty to adopt as we approach Earth's feared tipping points (such as the disappearance of Arctic ice in summer, permafrost melt, and so on). It also conforms with our intuition that state parties to the Paris Agreement should not be deemed compliant with their treaty obligations in the case where the Article 2.1 containment outcome is not achieved. Those who do not acknowledge the existence of a collective obligation in the treaty implicitly accept the possibility of a paradoxical result: each party ends up being legally compliant with the Paris Agreement's individual state obligations, thus rendering the Agreement a complete legal success, while at the same time global warming continues unabated and containment within the 2°C limit becomes impossible.
3.2. Collective Obligation in International Law Commentary
Article 42 of the Draft Articles on State Responsibility refers to a kind of obligation that is ‘owed to … the international community as a whole’.Footnote 27 The commentary to Article 42 adds that, in international law, a collective obligation is one that is owed ‘to a group of States or even the international community as a whole’.Footnote 28 These are states ‘which have combined to achieve some collective purpose and which may be considered for that purpose as making up a community of States’.Footnote 29 In addition, Article 48 of the Draft Articles refers to a collective obligation ‘established for the protection of a collective interest’ of states. The commentary to this article characterizes a collective obligation as an arrangement that ‘transcend[s] the sphere of bilateral relations of the States parties’.Footnote 30
Thus, in the Draft Articles we find reference to a type of obligation for which the subject (beneficiary) of the obligation is the international community as a whole. The holder of the obligation, however, is an individual state or states. Despite this difference, the Draft Articles are relevant to the issue I am considering insofar as they tell us that states can coalesce into an ‘international community’ to which a legal obligation is owed. The community thus becomes a legal person which can claim to be the subject of the obligation. By 2015, therefore, the idea of a community of states having legal personhood was not new. In the case of the Paris Agreement, states came together to achieve a collective purpose, or protect a collective interest: the containment of temperature rise below 2°C. While the Agreement makes them the subject of this obligation, no individual state or states could be the holder of it, because no state (or group of them) alone could demonstrably be the reason for a breach of the containment obligation. The uncertainties are too great to pinpoint blame on individual states for shattering the 2°C ceiling in circumstances in which all states continue to add GHGs to the existing stock of such gases in the atmosphere, which has been building up for at least two centuries. Therefore, the kind of obligation referred to in Article 42 of the Draft Articles is necessarily different from the kind of obligation appearing in the Paris Agreement. For the latter, not only the subject of the obligation but also the holder must be the international community as a whole.
The scholarly works referred to earlier, which see the existence of a collective obligation (or obligations) in the Paris Agreement,Footnote 31 may or may not intend to refer to the form of obligation contained in the Draft Articles. As I have already noted, the authors of those works do not shed any light on their claims about a collective obligation, so we cannot know whether a link to the Draft Articles was intended.
Another relevant notion of collective obligation, which is closer to the sense of the Paris Agreement than the Draft Articles, is Nollkaemper's notion of ‘shared responsibility’ in international law. In this view, shared responsibility ‘refers to situations where a multiplicity of actors contributes to a single harmful outcome, and legal responsibility for this harmful outcome is distributed among more than one of the contributing actors’.Footnote 32 Three forms of such shared responsibility exist, of which the ‘cumulative’ form is the most relevant to this discussion. Under cumulative shared responsibility, ‘each [state] contribution in itself would have been insufficient to cause the eventual harm … the eventual harm is caused in cumulation with other contributions by other actors’.Footnote 33 This is true of the causes of climate change. Even so, this theory of shared responsibility diverges from the idea of collective responsibility as I have described it in the Paris Agreement:
The third defining feature of shared responsibility is that the responsibility of two or more actors for their contribution to a particular outcome is distributed between them separately, rather than resting on them collectively. If the responsibility were to rest on a collectivity, it would no longer be shared, but would instead be a responsibility of the collectivity as such.Footnote 34
Nollkaemper's theory of shared responsibility goes beyond the Draft Article 42/48 model. This is because the theory distributes responsibility to states in proportion to their contribution to a collectively produced harm, despite the insufficiency of any one contribution to produce the harm. Nonetheless, it continues to place responsibility on individual states for conduct that contributes to the harmful result. Yet, we also see in the above-quoted passage that Nollkaemper does, in passing, recognize a form of responsibility that rests on the ‘collectivity as such’. While his theory is confined to cases of shared responsibility, not collective responsibility, he refers to the latter in terms that suggest that its existence, in legal terms, is entirely plausible.
Nollkaemper's shared responsibility theory does not itself work with the problem of climate change for the same reason that individual state responsibility does not work: a crossing of the 2°C warming threshold would be an event causally too complex to allow for proportionate attribution of individual state responsibility. The uncertainties and the intense build-up of anthropogenic gases in the atmosphere over a very long time period would make state-level responsibility attributions either inconceivable or entirely arbitrary. In this context, the notion of responsibility resting on the collectivity as such is indispensable.
Indeed, it is only a small step from Nollkaemper's distributed cumulative shared responsibility to the apparent collective cumulative shared responsibility of the Paris Agreement, which would confer legal responsibility upon a community of states to avoid a particular result.Footnote 35 Small as it may be in conceptual terms, this step was not, however, explicitly taken by the parties at COP-21 in December 2015. There is no language in either the preparatory documentation, or in Decision 1/CP.21,Footnote 36 to support the contention that a new form of legal obligation was deliberately created during the negotiations. Plausible though it may be as a legal position in theory, collective cumulative shared responsibility, being unprecedented at the time of the drafting of the Paris Agreement, needed clear words to support its emergence in practice. Instead, as will have been evident from my textual analysis in Section 2.1, legal interpretation is necessary for the contours of the collective obligation to be discerned. The availability of this interpretation explains why several scholars have been referring to ‘collective obligation(s)’ in their writings on the Paris Agreement. However, the very effort needed to bring to light an otherwise implicit collective cumulative shared responsibility undermines an argument to the effect that the creation of such an obligation was intended by the state parties to the treaty.
To summarize this section, while international law and related commentary have not provided for the existence of a collective obligation of the kind that subsists in the Paris Agreement, such a notion is not precluded.Footnote 37 States could have successfully created such an obligation, had they so wished, by bringing it robustly to the fore in the Agreement. Certainly, this form of obligation is necessary to deal with the problem of climate change. However, while the Paris Agreement harbours the notion implicitly, a legal innovation of such magnitude would have required explicit language – which is missing from the treaty. We may therefore conclude that the Paris Agreement, while it does create a collective obligation in form, does not make it a legal obligation with legally binding force in substance. It therefore subsists at the level of an aspiration, albeit a very important one.
4. INDIVIDUATION MECHANISM FOR THE COLLECTIVE AIM
Having clarified the nature of the collective obligation present in the Paris Agreement as one that is legally plausible, but not effectively adopted by the parties except as an aspiration, it remains to be seen how state parties are meant to discharge this collective aim. This brings us to a major weakness in the design of the Agreement, for in order to derive individual state obligations from its collective (below 2°C containment) aim, an individuation mechanism is needed. Without it, the collective aim is unrealizable. Yet, the Paris Agreement contains no such mechanism.
4.1. The Collective Aim's Link with Individual State Obligations
The parties to the Paris Agreement have recognized that the process leading to the submission of intended nationally determined contributions (INDCs) has generated, in effect, S-ambition. It did not result in T-ambition. This has put states on a path to breach their collective aim to contain global warming below the Article 2 limit. The parties to the treaty have noted ‘with concern’ that:
the estimated aggregate greenhouse gas emission levels in 2025 and 2030 resulting from the [INDCs] do not fall within least-cost 2°C scenarios but rather lead to a projected level of 55 gigatonnes in 2030, and also note … that much greater emission reduction efforts will be required than those associated with the [INDCs] in order to hold the increase in the global average temperature to below 2°C above pre-industrial levels by reducing emissions to 40 gigatonnes [in 2030].Footnote 38
The lack of T-ambition is thus acknowledged by the parties to the Paris Agreement. Nevertheless, their INDCs were converted into the first generation of NDCs. The journey towards containment below 2°C began, wrong-footedly, with NDCs of S-ambition rather than of T-ambition. Given this fact, the development of an equitable process to allocate the global budget – in short, an individuation mechanism – is now more urgent than ever, as states themselves seem to recognize. With this in mind, negotiations on the allocation of emissions for the second round of NDCs must commence as soon as possible.Footnote 39 The question is, on what basis, and in what forum? An objective basis for such discussions may exist, as I will show in Section 4.2 below. What is still missing, however, is a designated forum in which to conduct these discussions.
4.2. Equity Literature on the Mitigation Burden of States
A sophisticated literature on climate change ‘equity’ has emerged over the course of the last decade. Its premise is that a system to compare efforts under the 2°C ceiling – with the aim of revealing a state's progress toward its T-ambition – is a prerequisite for the success of the Paris Agreement.Footnote 40 Equity literature supplies components of an individuation mechanism, namely criteria from which to interrogate the T-ambition claims of states. Lessons from this equity literature may be summarized briefly as follows. Objective criteria do exist by which the degree of mitigation effort made by states may be measured and compared. The number of criteria considered relevant to this exercise is not large: around half a dozen are common to most studies, with some variations.Footnote 41 Because each metric has its shortcomings, a suite of them should be used when comparing state effort.Footnote 42 Numerous analyses of the comparative effort of both individual countries and groups of states have been undertaken, using different combinations of metrics and datasets. The results converge on broadly similar conclusions. For example, China's efforts declared in its NDC are repeatedly calculated to be less than its fair share in a below 2°C world.Footnote 43
The studies I have referred toFootnote 44 have one difficulty in common: the more countries that are incorporated into a study of comparative effort, the more demanding the calculations become.Footnote 45 However, as was the case with early climate models, this kind of difficulty is of a practical, not principled, nature. Once the relevant information needed for equity calculations is collected from at least all major emitters, comparative assessments of T-ambition could become possible for a larger number of countries.Footnote 46
4.3. An Individuation Mechanism under the Paris Agreement
A formulaic approach to the differentiation of state effort on the basis of objective criteria cannot constitute a complete individuation mechanism. A formula necessarily simplifies matters by excluding relevant yet unquantifiable factors, and therefore can produce only a rough allocation, the purpose of which would be to inform a political process. Still, an assessment of effort using objective criteria is far more than that which currently exists in the climate change regime. It should be developed by the UNFCCC's Subordinate Body on Scientific and Technical Advice and incorporated into the basis of negotiations on the adoption of targets reflecting T-ambition. The informational basis would provide the Paris Agreement parties with an objective reference for their discussions. It would also create tension and peer pressure in the negotiations, which is beneficial.Footnote 47 In the final analysis, the fairest result, and the demonstration of what is truly regarded as equitable by states (leaving aside the possibility that some weak states are diplomatically overpowered by others), is not the output of a formula, but a negotiated agreement.Footnote 48 The formula cannot be sufficient for individuation, but it might now have become necessary.
5. THE PARIS AGREEMENT HAS NO INDIVIDUATION FORUM
As discussed in the previous section, an individuation mechanism must include a calculation of T-ambition at the state level, using an agreed formula as a starting point. Formulaic results would be moderated through a process of negotiation (and peer pressure). The Paris Agreement does not provide for such a mechanism or an equivalent process.Footnote 49 It remains to consider whether the treaty does contain a process that could, with some adjustment, stand in for an individuation mechanism, or at least stand in for an individuation forum. In this section I argue that the only element in the Agreement that might serve as such a forum is the global stocktake.
5.1. States Have Consistently Avoided the Topic of Individuation
The Lima Call for Climate Action, issued at COP-20 in 2014, called on each state to explain ‘how [it] considers that its [INDC] is fair and ambitious’.Footnote 50 Through this declaration, states agreed that they would need to start to justify their claims to ambition. However, to date, states have consistently avoided justifying such claims. This ‘tradition’ of avoidance may be because of a preference by states to keep the detail underlying their justifications to themselves – for example, because they do not want to be impugned for failing to consider relevant criteria – or because they do not actually know how to justify ambition claims. Whatever the reasons, resistance to a justificatory narrative on ambition is a serious obstacle to generating T-ambition at the state level. In order to illustrate the lack of progress in this regard, I will consider the content of state reports submitted to the UNFCCC, and then summarize state responses to the Lima Call for transparency on ambition.
While almost all states in their periodic reports to the UNFCCC make a point of claiming that their proposed mitigation targets and actions are ‘ambitious’, or constitute a ‘fair’ contribution, most such claims are purely assertive and quickly move on to other matters.Footnote 51 We are left to presume that these are at most declarations of S-ambition: that is, they tell us about the state's ‘highest possible ambition’, as determined through internal considerations that do not involve any global comparative assessment. I would explain this mindset as being the result of more than a decade of Kyoto Protocol-induced thinking, whereby a state sets its own mitigation target, which is largely independent from, and uncoordinated with, that of any other state or any global target. The concept of ambition in this context is simplified to a state's progress against its own introspectively determined target. Over-achievement of this target is considered to be evidence of over-abundant ambition. It is a practice divorced from the practice of other states. It is isolationist rather than comparativist, reductionist rather than aggregationist.
A small proportion of states claim that their targets and actions are ambitious when considered in a broader context, but do so without further explanation.Footnote 52 More rarely still, states attempt to reference the Paris Agreement's Article 2.1 warming limit and its implied global budget. Nonetheless, these states also withhold all information about how their alleged T-ambition is determined.Footnote 53
An analysis of 163 INDCs carried out by Winkler and his co-authors on how states have sought to justify the equity of their proposed actions similarly shows that, despite the Lima Call, states rarely go to any trouble to justify their level of ambition.Footnote 54 The study found that a mere declaration of high ambition was considered sufficient by states in 75 INDCs.Footnote 55 Of the remaining 88 INDCs, only 20 claimed to align with the 2°C (or 1.5°C) ceiling in Article 2.1. Of these, only three cited the carbon budget calculated by the Intergovernmental Panel on Climate Change in the course of claiming that their planned emissions are equitable.Footnote 56 A full 101 states claimed that their ‘small share’ of global emissions was a sufficient basis in itself to render their INDC equitable.Footnote 57 This may suggest that, for some states, the key issue in the context of equity is one of economic development or capacity to mitigate (or the lack thereof), but it could also be evidence of a widespread unease about discussing their ambition in public. No state that claimed to have followed a method to calculate its ambition also claimed to have considered the aggregate global emissions that would result if all other states were to adopt that same method to determine their ambition.Footnote 58
Between the time of the Lima Call and the COP decision adopting the Paris Agreement, the requirement for states to do better on equity justification did not grow any stronger. The COP decision's language on equity is weak:
the information to be provided by Parties communicating their [NDCs] may include … information on … how the Party considers that its [NDC] is fair and ambitious, in the light of its national circumstances, and how it contributes towards achieving the objective of the Convention as set out in its Article 2.Footnote 59
As weak as this decision may be, it clearly distinguishes between what I have called S-ambition (reflected in the words ‘in the light of its national circumstances’) and T-ambition (denoted in the invitation to assess the impact of each NDC on the achievement of the Article 2 objective).
5.2. Transparency Framework
Article 13 of the Paris Agreement provides:
The transparency framework shall build on and enhance the transparency arrangements under the Convention … including national communications, biennial reports and biennial update reports, international assessment and review and international consultation and analysis.Footnote 60
None of the constitutive documents for such reporting-and-review processes under the UNFCCCFootnote 61 contain any provision obliging a state to determine, report on, or defend its T-ambition, as opposed to its S-ambition. The Transparency Framework under the Paris Agreement is no more than a framework to report information, check the adherence of state reports to the reporting guidelines (on content, methodologies and formatting), and give feedback to individual states on how to improve their reports.Footnote 62 Once that information has been checked by Technical Expert Review (TER) teams, it is to be fed into the global stocktake:
The purpose of the framework for transparency of action is to provide a clear understanding of climate change action in the light of the objective of the Convention as set out in its Article 2 … to inform the global stocktake under Article 14.Footnote 63
Therefore, if any of the information generated through the Transparency Framework provokes a discussion on equity (T-ambition), it will take place in the context of the global stocktake, as there is no place for it in the Transparency Framework itself. It certainly is not the role of TER teams to raise such questions.Footnote 64 Evidently, the Paris Agreement's Transparency Framework is about individual performance, not individual ambition – and certainly not about collective ambition.
5.3. Article 15 Mechanism
The Paris Agreement's Article 15 mechanism is ‘to facilitate implementation of and promote compliance with the provisions of this Agreement’.Footnote 65 The Article 15 Committee ‘shall be … facilitative in nature and function in a manner that is transparent, non-adversarial and non-punitive. The committee shall pay particular attention to the respective national capabilities and circumstances of Parties’.Footnote 66 It will not be able to focus on the parties’ collective obligation, and therefore the Committee is bound to have no significant impact beyond strengthening performance on the individual, legally binding obligations of states on technical requirements of the Agreement; that is to say, to the exclusion even of individual ambition.Footnote 67
5.4. Global Stocktake
The first global stocktake is set to be concluded in 2023. Article 14.1 of the Paris Agreement defines the purpose of the stocktake:
The [Conference of the Parties to the Paris Agreement] shall periodically take stock of the implementation of this Agreement to assess the collective progress towards achieving the purpose of this Agreement and its long-term goals […]. It shall do so in a comprehensive and facilitative manner, considering mitigation, adaptation and the means of implementation and support, and in the light of equity and the best available science.Footnote 68
It would seem from the wording of the provision that ‘collective progress’ will be the sole focus of the global stocktake, as measured against the Article 2.1 temperature limit. This would exclude ‘assessment of individual progress’ in contributing sufficiently to collective progress (i.e., state-level T-ambition). Consistent with this reading, Article 14.3 provides:
The outcome of the global stocktake shall inform Parties in updating and enhancing, in a nationally determined manner, their actions and support in accordance with the relevant provisions of this Agreement, as well as in enhancing international cooperation for climate action.
On one reading, it is for the parties themselves, individually, to work out what it is they have to do to raise the ambition of their NDCs to the level of T-ambition.Footnote 69 It is not for the global stocktake to dictate to states what their ambition should be.
However, as I have argued elsewhere, sufficient ambiguity has been allowed into the Paris Rulebook decision on the global stocktake to enable the stocktake to take on the role of an individuation forum, should parties wish to use it for that purpose.Footnote 70 Given that the point of the global stocktake is ‘informing Parties in updating and enhancing, in a nationally determined manner, their actions and support’,Footnote 71 this cannot succeed in practice if the so-called technical assessment stage in the global stocktake is kept strictly at the collective level and says nothing about comparative state-level effort. The 2018 Paris Rulebook decision establishes a Technical Dialogue, the terms of reference of which are broad and do not explicitly prohibit interstate comparison.Footnote 72 The ‘non-party stakeholders’ permitted to participate in the global stocktakeFootnote 73 will surely partake in such a comparison, even if the state parties themselves attempt to avoid it. Yet, the state parties are hardly encouraged to avoid it, as the category of ‘information to facilitate clarity, transparency and understanding of nationally determined contributions’Footnote 74 includes information on ‘[h]ow the Party considers that its nationally determined contribution is fair and ambitious’.Footnote 75 This information will serve as an input into the global stocktake.Footnote 76 As for the stocktake's outputs, they are to ‘summarize opportunities and challenges for enhancing action and support in the light of equity’.Footnote 77 What sense is there in keeping them at the collective level, when the ‘light of equity’ naturally shines on the individual level? Because the stocktake's outputs are to be considered at ‘high-level events’ that are completely unscripted,Footnote 78 it is hard to imagine that a strict focus on the ‘collective’ will be maintained at such events. The process, in practice, is likely to resolve itself into a long argument about individual ambition: in other words, a de facto individuation forum.
6. CONCLUSION
I have argued that several of the provisions of the Paris Agreement cannot reasonably be understood except as setting up a collective obligation – namely, the obligation that the parties to the Agreement observe the 2°C ceiling on warming, impliedly through a process of mutual collaboration to determine the mitigation ambition (T-ambition) of each party. In the collective logic of the Paris Agreement, a state must set its mitigation ambition so that it is a fair contribution, compared with the effort of other states. The logic also calls for mitigation that, in combination with that of other states, ensures that global average warming does not exceed 2°C. This textually derived collective obligation is the body and soul of the treaty. However, on a broader analysis, while in theory this obligation could have been made a legal one, in practice it was not adopted as a legal obligation binding upon the collectivity of states. Clear language to that effect is missing. Still, non-breach of the below 2°C containment aspiration is central to the success of the treaty. It thus becomes necessary to reduce the Paris Agreement's collective mitigation aim to state-level obligations, existing in parallel with, and aggregating up to, the collective aim. NDCs must be transformed from being nationally determined to being equitably determined (T-ambition). The Paris Agreement's answer to the isolationist and decidedly bottom-up (S-ambition) current practice may very well be the global stocktake. This mechanism is the only component of the new regime that could be used to oversee the 2°C collective aim and put real pressure on individual states to be more ambitious.
