Interpretation of Article 4.11 Paris Agreement

Legal assistance paper

All reasonable efforts have been made to ensure the accuracy of this information at the time the advice was produced (please refer to the date produced below). However, the materials have been prepared for informational purposes only and may have been superseded by more recent developments. They do not constitute formal legal advice or create a lawyer-client relationship. You should seek legal advice to take account of your own interests. To the extent permitted any liability is excluded. Those consulting the database may wish to contact LRI for clarifications and an updated analysis.

Date produced: 15/05/2017

What is the interpretation of Article 4.11 and in particular does it allow for downward revision of ambition in NDCs?


In order to respond to this question, we have undertaken a classic treaty interpretation analysis.  Our conclusion is that, while there is nothing specific in the Paris Agreement to prevent a downwards revision of a Party’s NDC, this would go against the ordinary meaning of Article 4.11, in its context within the Agreement, and the object and purpose of the Paris Agreement itself.  We agree with Prof Lavanya Rajamani’s conclusion – available at – that: “While it is of critical importance that the US, the second largest greenhouse gas emitter, remains in the Paris Agreement, if the cost at which it does so is a tacit acceptance from other Parties that ‘downgrading’ of the US NDC is legal and permissible under the Paris Agreement, it would be a serious price to pay. Not only will the legalisation of such downgrading upset the carefully balanced architecture of the Paris Agreement, it could also have a cascading effect on other Parties’ NDCs”.


The guiding principles on the interpretation of treaties are set out in Article 31 of the 1969 Vienna Convention on the Law of Treaties (the “Vienna Convention”).  These have been recognised by the International Court of Justice as reflecting customary international law.   Article 31.1 of the Vienna Convention states that “a treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose.”

Accordingly, the first step is to interpret the treaty provision in good faith, giving the terms of the provision their ordinary meaning. The determination of the ordinary meaning must be done in the context of the treaty and in the light of its object and purpose.

 1. Ordinary meaning of Article 4.11

Article 4.11 of the Agreement states that: “A Party may at any time adjust its existing nationally determined contribution with a view to enhancing its level of ambition, in accordance with guidance adopted by the Conference of the Parties serving as the meeting of the Parties to this Agreement.”

The ordinary meaning of “enhance” is “to raise the level of”, or to “increase”.  An ordinary reading of Article 4.11 therefore means that a Party that decides to adjust its existing NDC must do so in a way which increases contribution from that contained in its existing NDC.

2. Relevant context

The context to Article 4 is set initially by Article 3, which states: 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. The efforts of all Parties will represent a progression over time, while recognising the need to support developing country Parties for the effective implementation of this Agreement. Article 3 not only recognises that efforts must be “ambitious”, but states clearly that they will be a “progression over time”.

This expectation is then restated specifically in relation to Parties’ successive NDCs in Article 4.3: Each 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, reflecting its common but differentiated responsibilities and respective capabilities, in the light of the different national circumstances.

Article 4.3 clearly sets an expectation that Parties’ successive NDCs will be progressively higher in ambition.  Successive NDCs are filed on a five yearly basis.   Although Article 4.3 uses “will” rather than “shall”, it has been commented that the use of “will” “signals a strong but not mandatory obligation that each Party will undertake more ambitious actions over time”.   It is therefore relatively clear that in respect of successive NDCs, Parties would be in breach of Article 4.3 if they sought to regress to a lower level of ambition in a subsequent NDC.

Against this context, Article 4.11 deals with interim adjustments to existing NDCs.  This Article is intended to give parties that wish to increase their ambition in between NDC cycles the ability to do so.  The fact that it does not prohibit downwards revision of NDCs is not, in our view, intended to permit or condone downwards revision. Before even considering the purpose of the Paris Agreement as a whole (see below), downwards revision of NDCs would go against the expectation contained in Article 3 that parties should achieve a ‘progression over time’, as well as the text of Article 4.11 itself (“…enhancing its level of ambition”).

Finally, in terms of the context of Article 4.11 it is also important to note Article 4.2: “Each Party shall prepare, communicate and maintain successive nationally determined contributions that it intends to achieve.”  Although Rajamani (in the above blog) concludes that ‘maintain’ implies both that a Party must have an NDC in place and that it must preserve the level of ambition of that NDC, we are not convinced that this is necessarily intended.  It could be that Article 4.2 simply requires Parties to keep its NDC in place, as opposed to withdrawing it during the cycle.  Therefore we do not think that Article 4.2 supports or undermines the interpretation in this advice.

3. The object and purpose of the Paris Agreement

The purpose of the Paris Agreement is, in enhancing the implementation of the UNFCCC, to “strengthen the global response to the threat of climate change”, including “by holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels”.

The principle of progression is central to the Agreement as a whole. In the Preamble, Parties recognise “the need for an effective and progressive response to the urgent threat of climate change”. As set out above, Article 3 states that “the efforts of all Parties will represent a progression over time”.  And Article 14.1 states that the Conference of the Parties serves to “assess the collective progress towards achieving the purpose of [the Paris Agreement] and its long-term goals”. The principle of progression is particularly central to the Paris Agreement given the recognition of urgency in reaching the specific and ambitious temperature goals set out in Article 2.  For example, Article 4.1 emphasises that “In order to achieve the long-term temperature goals set out in Article 2, Parties aim to reach global peaking  of greenhouse gas emissions as soon as possible […]”.  The Agreement, therefore, relies on the national determination of efforts and the persuasive impact of the transparency framework and the global stocktake towards progression.

The principle of progression evidently supports an interpretation of Article 4.11 that precludes downwards revisions of NDCs.  As Christina Voigt stated in a recent article (albeit in respect of successive NDCs): “The principle of progression contained in Article 4.3. entails that each successive NDC has to progress beyond previous undertakings. A Party’s changing circumstances (e.g. a financial, political or economic crisis) cannot lead to a decrease in what can be considered its ‘highest possible ambition’ compared to the level contained in the previous NDC. It not only sets a “floor” for the next NDC, but requires each Party to go above and beyond each previous NDC”.

Related to this notion of progress is the primary duty of developed country Parties to “take the lead in combating climate change and the adverse effects thereof”, as set out in the first principle of the United Nations Framework Convention on Climate Change  (the ‘UNFCCC’) under Article 3.

4. History of the Paris negotiating text 

As set out in the Vienna Convention, Article 32, recourse may be had to the preparatory work of the treaty, in order to “confirm the meaning resulting from the application of Article 31” or “to determine the meaning when the interpretation according to Article 31 (a) leaves the meaning ambiguous or obscure”.

In this regard, paragraphs 180 and 181 of the Geneva negotiating text contemplated both upwards and downwards revisions of NDCs.

Paragraph 180 (which formed the basis for Article 4.11) stated that “Parties may, at any time, make upward adjustments to their commitments / contributions / actions”.   Although the express ‘upwards’ text was not retained, there is nothing to suggest that the revised wording in the final Article 4.11 was intended to move away from the expectation of upward adjustments.

At the same time, the Parties had considered including a provision allowing Parties to downgrade their NDCs. Various options were listed for consideration by the Parties in paragraph 181:

[Option 1: A Party to be allowed to exceptionally adjust its commitment / contribution, [in line with modalities developed by the governing body, ]subject to certain conditions, including: if subsequent rules differ substantially from the Party’s assumptions, or force majeure, provided that there is no backsliding.

Option 2: A [developing country Party][Party not included in annex X] may adjust its contribution when severely affected by an extreme natural event.

Option 3: A developing country Party may adjust its enhanced action when severely affected by an extreme natural event, force majeure, or when adequate finance, technology transfer and capacity-building support is not available.

Option 4: No other adjustments allowed.

Option 5: A Party may exceptionally adjust its [proposed / provisional] commitment / contribution, if subsequent rules differ substantially from the Party’s assumptions[, as specified in the information to be provided pursuant to the reference to the provision addressing accompanying information.]

Two of the five options that were considered were only intended for developing country Parties. Justified reasons for developing country Parties to downgrade their NDC included being severely affected by an extreme natural event; force majeure; or when adequate finance, technology transfer and capacity-building support were not available. Two other options considered applying to all Parties, but on an exceptional basis only; with the first option allowing Parties to downgrade their NDCs “subject to certain conditions, including: if subsequent rules differ substantially, or force majeure, provided that there is no backsliding”, and the other option only allowing Parties to adjust “if subsequent rules differ substantially from the Party’s assumptions”.

Ultimately, none of these options were included in the final text of the Agreement. This could be read as signalling an openness to downgrading or it could be read as an acknowledgement that downgrading is not in keeping with the spirit of the Paris Agreement and thus does not feature in it.

5. Conclusion and implications

In light of the above, although there is no direct prohibition of Parties “downgrading” their NDCs, our view is that it would go against the textual and purposive interpretations of Article 4.11 of the Agreement to conclude that Parties may freely adjust their NDCs downwards.

Should Parties interpret Article 4.11 as allowing “downgrading” of NDCs, this would have important consequences on the interpretation of other provisions of Article 4 of the Agreement.  In particular, it would give developing country Parties more leeway to interpret Article 4.4 as optional – Article 4.4 states that “Developing country Parties should continue enhancing their mitigation efforts, and are encouraged to move over time towards economy-wide emission reduction or limitation targets in the light of different national circumstances”. The use of “should” rather than “shall” could be seen to give developing country Parties more of a choice than developed country Parties. In a similar vein, Article 4.6 of the Agreement could then be read as suggesting “flexibility on progression to [least developed country Parties]”.

Accordingly, we agree that the better interpretation is that a Party may not revise its NDC downwards.  That said, realistically, a Party may not always be able to achieve its projected NDC, despite its best efforts and its compliance with the provisions of Article 4.  In this respect it is important to recall that Article 4.2 establishes a good faith expectation that Parties intend to achieve their NDC, but it does not require them to do so.   In this regard, another point for consideration is that a Party could seek to suspend its obligations under the Agreement based on a “fundamental change of circumstances”, pursuant to Article 62 of the Vienna Convention. Although we have not canvassed the interpretation of this clause in this advice, we do note that, when the International Law Commission discussed what constituted a “fundamental change of circumstances”, the question of whether a change of Governmental policy qualified as such was left open.