Legal status of Paris Rulebook

Legal assistance paper

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Date produced: 30/10/2017

1. As the so-called “Paris Rulebook” will be adopted as a series of CMA decisions, what will be its legal status? Does the fact that the Rulebook will need to be implemented nationally give it a different legal status than “normal” COP decisions? 

2. Given that the Paris Rulebook will take the form of a COP decision, how can Parties be made to comply with the rules? What, if any, legal hooks are there to make it legally binding on them?


1. Legal nature of the Rulebook

a) Background: Paris Agreement and Party-specific obligations

The Paris Agreement (PA)[1] can be considered a formal and binding international treaty under the Vienna Convention of the Law of Treaties, given that it is a written instrument,[2] it uses “entry into force” language (Article 21), employs the usual treaty “ratification, acceptance or approval” process (Article 20), and contains the restriction against reservations (ratification covers the full Agreement).[3]

While the Agreement is formal and binding, it contains both provisions that create binding legal obligations and provisions that create non-binding commitments.[4] Importantly, the Party-specific binding legal obligations are “obligations of conduct,” rather than “obligations of result”[5] and all but one are procedural, covering activities of reporting, verification and review. The exception is Article 4.2, phrase 2: “Parties shall pursue domestic mitigation measures, with the aim of achieving the objectives of [their NDCs].” However, the PA both lacks language addressing the specific conduct for this obligation, and explicitly affirms each Party’s prerogative to adjust its NDC at will (Arts 4.2 and 4.11), thus “preserv[ing] national discretion over both a Party’s international target and its domestic policymaking.”[6]

Notably, most of the obligations essentially mirror those of the UN Framework Convention on Climate Change (UNFCCC) for developed country Parties, with added refinement, precision and transparency, in particular, on transparency of support provided to/leveraged for developing country Parties.[7] Developing country Parties are now tasked with greater responsibility to implement and report than in the UNFCCC, though are provided flexibility in meeting their obligations through various provisions.

b) The Paris Agreement Rulebook and its legal status

The PA Rulebook components will derive from a suite of requests in decision 1/CP.21 that make up the backbone of “the work programme on the Paris Agreement.”  Development of the Rulebook is primarily the charge of the Ad Hoc Working Group on the Paris Agreement (APA); yet, both the Subsidiary Body for Scientific and Technological Advice (SBSTA) and the Subsidiary Body for Implementation (SBI) have responsibility for aspects of the work programme too.

The Rulebook components will be largely compiled and agreed to by the APA and forwarded to the PA’s primary treaty body, the Conference of the Parties meeting as the Parties to the Paris Agreement (CMA), with the recommendation to adopt. The Rulebook’s legal status is determined by its relationship to the Paris Agreement:

A treaty may grant authority to its supreme or primary treaty body to implement certain of its provisions, including those that establish binding obligations on some or all of its Parties, and this can be either implicit or explicit. In some instances, treaties have granted explicit authority to their supreme bodies to create binding obligations beyond those of the original instruments. Article 25 of the UN Charter (binding measure to protect peace and security) or Article 2.9 of the Montreal Protocol (binding decisions on substances that deplete the ozone layer) are examples of treaty bodies explicitly empowered to establish binding obligations for Parties beyond those of the original instruments.[8]

The Convention and its Kyoto Protocol (KP) delegate explicit authority to their primary bodies to review the implementation of the original instruments, including, for example, establishing methodologies Parties must utilize to fulfil their obligations of conduct.[9] The KP also gives explicit authority to its governing body (the Conference of the Parties serving as the meeting of the Parties to the Protocol (CMP)) to implement provisions regarding how Annex I Parties are to/may meet their results-based obligations. This was inter alia addressed by the 2001 Marrakech Accords of CP.7[10] (initial rules and guidelines for KP implementation adopted by CMP1 in 2005[11]).

However, no provisions of the UNFCCC, the KP or the PA explicitly delegate powers to create new legal binding obligations on the Parties to their primary treaty body (the COP, CMP or CMA respectively). A contrario, the KP makes it clear that, for decisions (or other measure) to be binding on the Parties a formal amendment to the Kyoto Protocol would be necessary (Art.18 KP). As a result, COP decisions in the UNFCCC context indicate a political commitment but are generally not considered legally binding on the Parties.

However, while COP decisions are not binding in the same way as an obligation under a treaty they nevertheless have some legal force. They bind internal institutions, such as the secretariat or the subsidiary bodies, and create new processes and mechanisms for the implementation of the governing treaty. This can include rules and incentives for compliance or financial and other means of support. In relations to the parties of the UNFCCC and the PA, future COP decisions may primarily have a “soft law character”, while for all internal purposes they could provide a stringent framework for the operation of Paris Agreement and the recognition of Parties’ efforts.

To a large extent, the assessment of the Rulebook’s legal effect will, therefore, depend on a case-by-case analysis of the different components in conjunction with the relevant provisions in the Paris Agreement. In this context, the content, precision and prescriptiveness of the decision’s provisions as well as the existence of mechanisms or procedures to scrutinize subsequent implementation will be important considerations.

The Paris Agreement, for example, requires that a number of Parties’ obligations must be fulfilled “in accordance with” decision 1/CP.21, relevant CMA decisions, or both (Art. 4.8, 4.9, 4.13, 6.2, 9.7, 13.13 (by implication)). What the Rulebook contains, both through initial but also further subsequent CMA decisions regarding these specific articles, will shape the implementation of the Paris Agreement and may de facto generate a significant degree of legal force to adhere to the agreed methodologies, processes and rules.

What this means in practice for States, in terms of domestic implementation, will depend on the actual content of the Rulebook and their respective domestic legal order.[12] All Parties are expected to engage in the relevant Party-specific procedures called for in the PA (e.g. the practice of regular documentation, reporting and verification of mitigation policies and measures, their projected impact, and, for developed country Parties, the means of implementation they have provided to developing country Parties). Depending on the nature and reach of their existing laws and policies, Parties to the PA may or may not need to promulgate new laws in response to the Party-specific elements of the CMA’s Rulebook decisions.

More than likely, some non-Annex I Parties will find it necessary to adopt new laws to meet their obligations under the PA, and can base those on the guidelines within the forthcoming Rulebook. Notably, the PA affords these Parties flexibility in meeting their obligations. In all cases, the meeting of these requirements must be authorized and assumed by appropriate entities within each Party’s governmental system.

2. Compliance with the Rulebook

The PA contains no results-based obligations in which to sink legal hooks for compliance. To maximize compliance with the legally binding, conduct-based obligations of individual Parties, the PA established a mechanism and associated committee “to facilitate implementation and promote compliance” (Article 15). It then tasked this regime generally (though with important parameters), and charged the CMA with adopting the modalities and procedures for the mechanism and its committee. A Party may be influenced, but not compelled, to change its behaviour by a non-compliance ruling the committee might issue. In contrast, the compliance mechanism of the Kyoto Protocol was able to centre on the precise legal obligations of result it established.[13]

The linkages between Article 13’s “enhanced transparency framework” and other provisions seem to provide the strongest soft law support for compliance with individual Party obligations. Article 13 establishes a tracking process for how Parties are doing on their NDCs (Art. 13.7), bolstered by a technical expert review and multilateral consideration of each Party’s progress (Art. 13.11) and a directive for CMA-1 to build on existing Convention transparency arrangements (Art. 13.13). The new transparency framework will also “eventually supersede” the Convention’s measurement, reporting and verification system.[14] Moreover, a periodic robust rendering of where we stand from both a planetary and granular perspective will be provided by the combination of three linkages articulated by Articles 13.5 and 13.6:

  • “Transparency of action” linked back to Article 2 (PA Purpose), Article 4 (NDCs) and Article 7 (adaptation action);
  • “Transparency of support” linked back to Articles 4, 7, 9, 10 and 11 (covering “provision of support provided and received by relevant individual Parties”); and
  • Both transparency of action and of support linked forward to the Article 14 global stocktake.

Creating modalities and procedures that instil the rigor and attain the goals stated in Article 13 and achieve the intended built-in flexibility to accommodate developing country Parties’ capacities will be a significant challenge for the CMA and its supporting bodies. Substantive concerns include preventing double counting of mitigation outcomes[15] and ensuring climate finance transparency and provision. Notably, for the long-standing double counting concern,[16] there is no direct linkage between Article 13 and Article 6, establishing a new voluntary institutional framework for the use of “internationally transferred mitigation outcomes” (market-based mechanism(s)). There are ongoing issues for climate finance transparency involving measuring, reporting and verifying that both lie within and extend beyond the UNFCCC,[17] though there are actions available to enhance those within the CMA’s jurisdiction.[18] Ensuring the provision of even promised climate finance is beyond the PA’s and CMA’s capacity.

Despite the absence of legal hooks for ensuring performance under the PA, there is “a growing body of literature supporting the broad proposition that commitments made in non-legally binding instruments or provisions may achieve better rates of compliance than commitments made in ‘harder’ legal form.”[19] Furthermore, a robust transparency mechanism will instrumentally facilitate the reputational pressure and potential domestic legal action (by e.g., civil society, sub-nationals, market institutions and players) States will face instead, if they don’t comply with the PA’s provisions.[20]




[3] Ralph Bodle and Sebastian Oberthür, Legal Form of the Paris Agreement and Nature of its Obligations, at 93, in The Paris Agreement on Climate Change: Analysis and Commentary, D. Klein, MP Carazp, M. Doelle, J. Bulmer, and A. Higham, eds., Oxford Univ. Press (2017), Oxford Univ., UK.

[4] Tess Bridgeman, Paris is a Binding Agreement: Here’s Why that Matters, Just Security, at the Center for Human Rights and Global Justice, New York University School of Law (June 4, 2017),

[5] Id, at 146.

[6] Legal Issues Related to the Paris Agreement, Center for Climate and Energy Solutions brief, May 2017,; also: In keeping with the international law principle of State sovereignty (UN Resolution 2625 (XXV), and the acknowledgement of it in the UNFCCC Preamble (

[7] See Paris Agreement articles 4, 7, 9, 10, 11, 13.

[8] Daniel Bodansky, Legally binding vs. non-legally binding instruments, pp155-165, at p.157; in Towards a Workable and Effective Climate Regime, Barrett, Scott, Carlo Carraro and Jaime de Melo eds. eBook, CEPR and FERDI, Nov. 2015. (“…the issue of an instrument’s legal form is distinct from the issue of whether particular provisions create legal obligations.”), See also Porter, et al., supra note 13, and COP Decisions: Substance and Mandates, Oct. 4, 2010, Legal Response Initiative,

[9] For example, Conv. Art. 7.2(d) and KP Arts 3.4, 5.2, 5.3.



[12] The Status of UNFCCC COP and other Treaty Body Decisions Under US Law, Nov. 23, 2011, Legal Response Initiative,

[13] Id, at para 18.

[14] Decision 1/CP.21 para 98,

[15] Lambert Schneider, Anja Kollmuss, and Michael Lazarus, Addressing the risk of double counting emissions reductions under the UNFCCC, Stockholm Environment Institute, Working Paper 2014–02 (April 2014),

[16] As part of three SBSTA work programmes on market and non-market mechanisms ( See SBSTA 41-SBSTA 44 outcomes via

[17] Andrea Iro, Measuring, Reporting and Verifying Climate Finance, Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH (May 2014),

[18] Jane Ellis and Sara Moarif, Enhancing transparency of climate finance under the Paris Agreement: lessons from experience, OECD (Oct. 2016), See also Bodansky, supra note 14, at 7-8.

[19] Vernon Rive, Reflections on the Paris Agreement, Social Sciences Research Network (May 10, 2016), (for download).

[20] See Jana von Stein, Compliance with International Law, at 12 (June 2017), in The International Studies Encyclopedia, Robert A. Denemark and Renée Marlin-Bennett, eds., (2017) in assoc. with the International Studies Association, Wiley Blackwell Publishers,