INTERNATIONAL COURT OF JUSTICE
OBLIGATIONS OF STATES IN RESPECT OF CLIMATE CHANGE
(REQUEST FOR AN ADVISORY OPINION)
ANSWERS TO THE QUESTIONS P OSED BY JUDGES
20 DECEMBER 2024
I. INTRODUCTION
1. On 13 December 2024, certain Judges of the International Court of Justice ("ICJ") posed
questions to all the participants in the advisory proceedings on the Obligations of States in
respect of Climate Change. 1 After careful consideration, Latvia has decided to respond to
the question posed by Judge Tladi (Section II).
2. Latvia fully maintains the views expressed in its written statement, written comments, and
oral submissions relevant to the questions posed by Judge Cleveland, Judge Aurescu, and
Judge Charlesworth.
II. THE QUESTION POSED BY JUDGE TLADI
3. Judge Tladi posed the following question:
In their written and oral pleadings, Participants have generally engaged in an
interpretation of the various paragraphs of Article 4 of the Paris Agreement. Many
Participants have, on the basis of this interpretation, come to the conclusion that, to the
extent that Article 4 imposes any obligations in respect of nationally determined
contributions, these are procedural obligations. Participants coming to this conclusion
have, in general, relied on the ordinary meaning of the words, context and sometimes
some elements in Article 31 (3) of the Vienna Convention on the Law of Treaties. I
would like to know from the Participants whether, according to them, 'the object and
purpose' of the Paris Agreement, and the object and purpose of the climate change treaty
framework in general, has any effect on this interpretation and if so, what effect does it
have?2
4. Article 31, paragraph 1, of the Vienna Convention on the Law of Treaties provides, in line
with customary international law, that a treaty must be interpreted in good faith in
accordance with the ordinary meaning to be given to the terms of the treaty in their context
1 Obligations of States in respect of Climate Change (Request for an Advisory Opinion) CR 2024/54 39-
41.
2 Ibid 40.
2
and in the light of its object and purpose. 3 The ICJ has treated the object and purpose of the
treaty as an important element of the interpretative exercise.4
5. Latvia throughout these proceedings has taken the view that the obligation to mitigate
adverse effects of climate change in Article 4 of the Paris Agreement has a primarily, but
not exclusively, procedural character. Latvia has also been consistent in arguing that this
obligation is subject to requirements of due diligence, and that discretion under Article 4 is
not unlimited. One effect that the object and purpose of the Paris Agreement and climate
change treaty framework may have on interpretation of Article 4 is to inform how this
discretion is to be calibrated.
6. Latvia's written and oral submissions excerpted below demonstrate its approach to
interpretation of Article 4 of the Paris Agreement and the role of the object and purpose. 5
Latvia notes that other participants in these proceedings have approached the interpretative
exercise in similar terms in their oral submissions.6
A. Oral submissions
7. In its oral submissions, 7 Latvia argued that:
... the obligation to mitigate adverse effects of climate change in Article 4, paragraph 2,
of the Paris Agreement is an obligation of conduct, not result, and is subject to
requirements of due diligence. 8 The discretion accorded to States by this provision in
designing their nationally determined contributions ("NDC") and measures to pursue
3 Arbitral Award of 3 October 1899 (Guyana v. Venezuela) (Preliminary Objection) [2023] ICJ Rep 262
paras 103, 104.
4 Ibid paras 94-95. See also Immunities and Criminal Proceedings (Equatorial Guinea v. France) [2020]
ICJ Rep 300 paras 66, 68, 73; Arbitral Award of 3 October 1899 (Guyana v. Venezuela) (Jurisdiction of the Court)
[2020] ICJ Rep 455 paras 73, 83, 86, 97, 114, 115, 130; Certain Iranian Assets (Islamic Republic of Iran v. United
States of America) [2023] ICJ Rep 51 paras 43, 102, 214.
5 The excerpts from written and oral submissions omit the paragraph numbers. Footnotes are renumbered
and, where necessary for cross-references, adjusted.
6 CR 2024/36 p. 62, paras. 21-22 (Blake); CR 2024/39 pp. 27-28, para. 11, p. 30, para. 14 (Sarvarian); CR
2024/39 p. 46, paras. 4-9 (Jervell); CR 2024/41 pp. 10-11, paras. 11, 14 (Colas); CR 2024/43 p. 36, paras. 22-25
(Okowa); CR 2024/49 p. 47, paras. 13-14 (Thouvenin); CR 2024/49 p. 66, para. 15 (Loewenstein).
7 CR 2024/44 p. 13 paras. 8-9 (Paparinskis).
8 Written Statement African Union, para 132; Written Statement Solomon Islands, para 78; Written
Statement Tonga, para 156.
3
them, while wide, is not unlimited. Vanuatu has noted that State obligations are bounded
by "parameters" that provide "regime-specific markers for due diligence". 9 Latvia agrees.
In performing their mitigation obligations under Article 4, paragraph 2, States must act
with due diligence:
- in good faith to ensure that the object and purpose of the treaty, particularly the l .5°C
temperature goal, are properly pursued; 10
- "in accordance with best available science"; 11
- informed by the "highest possible ambition", progression over time, and
differentiation; 12
- in line with procedural obligations regarding preparation, communication,
maintenance, and implementation of NDCs; 13 and
- taking into account relevant decisions of the respective COPs. 14
Discretion under such a treaty provision, as a corollary, also entails a duty "to exercise
the power properly and reasonably", to borrow the language used by Judge Xue in
Whaling in the Antarctic. 15 For Article 4, paragraph 2, it means that the NDCs must be
genuinely for the purpose, and bear a reasonable relation to the objectives of achieving
the temperature goal. Domestic mitigation measures must be for the purpose of achieving
such contributions and bear a reasonable relation to the Party's stated objectives.
9 Written Statement Vanuatu, para 411.
10 Paris Agreement, Art. 4, para 1; see also Gabcikovo-Nagymaros Project (Hungary/Slovakia), Judgment,
/CJ Reports 1997, para 142.
11 Paris Agreement, Art. 4, para. I.
12 Ibid., Art. 4, paras. 2-3.
13 Ibid., Art. 4. Paras. 8-9, read together with Art. 14, para. 3; Art. 4, para. 15.
14 UNFCCC, Art. 7; Paris Agreement, Art. 16. See also CR 2024/41, pp. 12-13, paras. 19-20 (France,
Colas).
15 Whaling in the Antarctic (Australia v. Japan: New Zealand lnte111ening), Judgment, I.CJ. Reports 2014,
separate opinion of Judge Xue, p. 422, para. 9.
4
B. Written comments
8. In its written comments, 16 Latvia argued that:
The temperature goal
The Paris Agreement's temperature goal aims to hold 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 l .5°C above pre-industrial levels". 17 Subsequent to the
conclusion of the Paris Agreement, Parties have committed to "pursue efforts to limit
the temperature increase to l .5°C". 18 Participants in these proceedings have emphasized
the importance of the 1.5°C goal. 19 For example, Vanuatu refers to the recognition by
the Glasgow Climate Pact at the Conference of the Parties ("COP") 26 that, to achieve
the 1.5°C temperature goal, there would need to be "rapid, deep and sustained
reductions in global greenhouse gas emissions, including reducing global carbon
dioxide emissions by 45 per cent by 2030 relative to the 2010 level and to net zero
around mid-century".20
Latvia agrees with the emphasis on the importance of the 1.5°C temperature goal and
the importance of implementing the Parties' resolution to pursue efforts to achieve that
goal. In its Written Statement, Latvia highlighted the l .5°C target goal, and specifically
drew attention to the Outcome of the First Global Stocktake ("Outcome").21 The
Outcome "resolves" to pursue efforts towards l .5°C and "emphasizes the need for
urgent action and support to keep the l.5°C goal within reach".22 The Outcome also
"recognizes" that there must be "deep, rapid and sustained reductions in global
greenhouse gas emissions of 43 per cent by 2030 and 60 per cent by 2035 relative to
the 2019 level and reaching net zero carbon dioxide emissions by 2050", in order to
16 Written Comments of Latvia (14 August 2024) <https://www.icj-cij.org/sites/default/files/caserelated/
18 7 /18 7-20240814-wri-06-00-en. pdf> paras 13-20.
17 Paris Agreement Adopted in Decision l/CP.21, 'Adoption of the Paris Agreement' ( adopted 12 December
2015) FCCC/CP/2015/L.9 (29 January 2016), (entry into force 4 November 2016) 3156 UNTS 79 (signed by
Latvia on 22 April 2016, ratified on 16 March 2017) art Article 2(a).
18 See Decision 1/CMA.3, 'Glasgow Climate Pact' (13 November 2021) FCCCIP A/CMA/2021/10/ Add. I
[21]. The net zero goal is articulated in the Paris Agreement (n 17) art 4(1), and denotes "a balance between
anthropogenic emissions by sources and removals by sinks of greenhouse gases".
19 See WS EU [152]; also WS COSIS [110]-[ l I l ]; WS Dominican Republic [4.28]-[4.29]; WS Grenada
[26]-[30]; WS Mauritius [IOI]; WS Seychelles [91]; WS Timor-Leste [98]-[99]; WS Tuvalu [105]-[ l l 0]; WS UK
[63]; ws us [3.39].
20 WS Vanuatu [403], generally [401]-[403].
21 WS Latvia [18] and fn 28.
22 Decision 1/CMA.5, 'Outcome of the First Global Stocktake' (13 December 2023)
FCCCIPA/CMA/2023/16/Add.J [4]-[5] (emphasis in the original).
5
achieve the l .5°C target.23 Moreover, in pursuit of efforts to achieve the l .5°C goal,
Parties should act to enhance international cooperation in accordance with the
"Roadmap to l.5°C". 24
Parties are obliged to design and implement their nationally determined contributions
("NDC") in light of the Outcome.25 Consequently, current NDCs must be informed by
the need to pursue efforts to make the deep, rapid and sustained reductions in
anthropogenic GHG emissions that meaningfully contribute to the timely reductions in
global greenhouse gas emissions needed to keep emissions in line with the l .5°C goal.26
Binding GHG mitigation obligations
Several participants have observed that the mitigation obligation in Article 4, paragraph
2, of the Paris Agreement is an obligation of conduct, not result, which is subject to
requirements of due diligence.27 A number of participants have also submitted that,
notwithstanding the large measure of national discretion accorded to States in designing
their NDCs and in designing measures to pursue their NDCs, that discretion is not
unlimited.28 For example, Vanuatu states that State obligations are bounded by
"parameters" that provide "regime-specific markers for due diligence".29 Latvia agrees,
and in its Written Statement made the same point in very similar terms.30
For several participants, the main limitations on the discretion to determine national
contributions involve the temperature goal and objectives of the Paris Agreement31 and
criteria specified in Article 3 and Article 4, paragraphs 1, 3 and 4. 32 In addition, several
participants consider that there is a need to take into account the best available scientific
23 Ibid [27] ( emphasis in the original). Moreover, the Outcome sets out a number of clearly defined 'global
efforts' for achieving the necessary reductions, to which it "calls on" Parties to contribute, [28], and which should
inform nationally determined contributions ("NDC").
24 'Outcome' (n 22) [191].
25 In accordance with Paris Agreement (n 17) arts 4(9), 14(3).
26 Such efforts should be made in light of national circumstances, the best available science and in a
nationally determined manner: 'Outcome' (n 22) [39].
27 See WS EU [135]; also WS AU [132]; WS China [48]; WS New Zealand [61]; WS Portugal [55]; WS
Solomon Islands [78]; WS Tonga [147].
28 See WS EU [135]; also WS Antigua and Barbuda [243]; WS AU [95]; WS France [28]; WS Singapore
[3.35]; WS Solomon Islands [79]; WS Switzerland [57]; WS Tonga [156].
29 WS Vanuatu [411].
30 Generally WS Latvia [28]-[3 l ].
31 See WS EU [140]; also WS Bahamas [86]; WS COSIS [113]; WS France [29]; WS Germany [50]; WS
Kenya [5.36]; WS New Zealand [61]; WS Portugal [53]; WS Singapore [3.35a]; WS Timor-Leste [118].
32 See EU [140], [146)-(150); also WS Antigua and Barbuda [253)-(266); WS AU [133); WS China [49);
WS Grenada [33); WS Kenya [5.37]; WS Korea [20); WS Marshall Islands [42); WS Mauritius [107); WS
Seychelles [72)-(77); WS Solomon Islands [74)-(78); WS Timor-Leste [118); WS Tonga [149)-[153); WS US
[3.18).
6
evidence33 and to conform to the requirements of good faith.34 Vanuatu, for example,
states that due diligence involves the following standards: first, the requirements of
"progression over time" and "highest possible ambition" as parameters that shape "the
requisite due diligence of States in relation to addressing climate harms";35 secondly,
the temperature goal and net zero that create a "normative expectation that Parties'
actions will be aligned with these goals";36 thirdly, an "expectation that Parties' actions
will reflect their common but differentiated responsibilities and respective capabilities,
in light of different national circumstances";37 fourthly, the nature and degree of harm
that would be suffered in the absence of diligent action;38 and,fifthly, the requirement
of good faith.39 Latvia generally agrees.
As Latvia stated in its Written Statement, in performing their obligations under Article
4, paragraph 2, States must act with due diligence "to ensure that the objectives of the
Paris Agreement are met", and that the standards of diligence are "informed by the
'highest possible ambition', progression over time and differentiation, as noted in
Article 4, paragraphs 3 and 4".40 To this Latvia would add the need to act "in accordance
with best available science", noted in Article 4, paragraph 1, of the Paris Agreement.
The application of these elements as regime-based parameters for due diligence derives
support from the effective interpretation of Article 4, as well as from the Court's
approach to standards that, though "not being formally binding, are, to the extent
relevant, to be taken into account".41
Latvia also considers that good faith, together with the temperature goal, condition the
performance of the obligations in Article 4, paragraph 2, to ensure that the Agreement's
objectives are properly pursued.42 The Court has stated that "[t]he principle of good
faith obliges the Parties to apply [the Treaty] in a reasonable way and in such a manner
that its purpose can be realized".43 In relation to the performance of discretionary
33 See WS EU [138]-[139]; also WS Antigua and Barbuda [250]-[252]; WS COSIS [92]; WS Germany
[48]; WS Mauritius [105]; WS Solomon Islands [82]; WS St Lucia [54].
34 See WS AU [96]; WS Belize [56]; WS Colombia [3.21]-[3.22]; WS France [24], [55]; WS Korea [20];
WS Solomon Islands [78]; WS Tuvalu [88].
35 WS Vanuatu [414]; also ibid [410], [411].
36 Ibid [413].
37 Ibid [415].
38 Ibid [416].
39 Ibid [417].
40 WS Latvia WS [30). In addition to these "parameters", Latvia also highlighted the existence of other
procedural obligations, notably under Paris Agreement (n 17) arts 4(8), (9), ( 15), 14(3 ), see WS Latvia [31].
41 Pulp Mills on the River Uruguay (Argentina v. Uruguay) (Judgment) [2010] ICJ Rep 14 [62].
42 WS Latvia [29].
43 Gabcikovo-Nagymaros Project (HungmJ,/S/ovakia) (Judgment) [1997] ICJ Rep 7 [142).
7
[73].
powers under a treaty, such powers "must be exercised reasonably and in good faith",44
and in line with factors set out in the treaty.45 Such factors include objectives expressly
contained within the relevant treaty, "in the light of which the other Treaty provisions
are to be interpreted and applied".46 Where there is a duty, under a treaty, to act for a
particular purpose, the duty of good faith performance requires that measures
undertaken in reliance on the treaty should pursue that purpose,47 and that both the
design and implementation of any measures taken in pursuit of that purpose should be
reasonable in relation to achieving their stated objectives.48
The temperature goal in Article 2, read in line with subsequent decisions of the
Conference of the Parties serving as the meeting of the Parties ("CMA"), constitutes
one of the three express objectives of the Paris Agreement. As stated in Article 3, the
general purpose of "nationally determined contributions", under all parts of the Paris
Agreement, expressly including Article 4, is to achieve the temperature goal.49
Moreover, according to Article 4, paragraph 1, the objective of climate change
mitigation measures is "[i]n order to achieve the long-term temperature goal set out in
Article 2". The design and implementation of NDCs, understood in accordance with
the ordinary meaning of the terms, in their context within Article 4 and the immediately
preceding Articles 2 and 3, and in light of the Paris Agreement's object and purpose,
must be for the purpose of achieving the temperature goal.
In Latvia's view, this entails that, although there is a wide discretion for States to
determine the content of their NDCs, under Article 4, paragraph 2, the NDC must be
genuinely for the purpose of, and bear a reasonable relation to the objectives of,
achieving the temperature goal. Moreover, good faith performance of the obligation to
"pursue domestic mitigation measures, with the aim of achieving the objectives of such
contributions" requires that domestic mitigation measures are for the purpose of
achieving such contributions and bear a reasonable relation to the Party's stated
objectives.
44 Immunities and Criminal Proceedings (Equatorial Guinea v. France) (Judgment) [2020] ICJ Rep 300
45 Rights of Nationals of the United States of America in Morocco (France v. United States of America)
(Judgment) [1952] ICJ Rep 176,212.
46 Oil Platforms (Islamic Republic of Iran v. United States of America) (Preliminary Objections) [1996]
ICJ Rep 803 [28].
47 Whaling in the Antarctic (Australia v. Japan: New Zealand Inte111ening) (Judgment) [2014] ICJ Rep 226
[68].
48 Ibid [67]. See also ibid Separate Opinion of Judge Xue 420 [9].
49 Paris Agreement (n 17) art 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 pwpose of this Agreement as set out in Article 2. The efforts of all Parties will
represent a progression over time, while recognizing the need to support developing country Parties for the
effective implementation of this Agreement.' (Emphasis added)
8
C. Written statement
9. In its written statement,50 Latvia argued that:
The purpose of the Paris Agreement is directly connected to "enhancing the
implementation of the [United Nations Framework] Convention [on Climate Change],
including its objective". 51 The "ultimate objective" of the UNFCCC is the "stabilization
of greenhouse gas concentrations in the atmosphere at a level that would prevent
dangerous anthropogenic interference with the climate system".52 The objective of the
Paris Agreement is explained in Article 2 as having three aspects:
(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, recognizing that this would significantly reduce the risks
and impacts of climate change;
(b) Increasing the ability to adapt to the adverse impacts of climate change and
foster climate resilience and low greenhouse gas emissions development, in a manner
that does not threaten food production; and
(c) Making finance flows consistent with a pathway towards low greenhouse gas
emissions and climate-resilient development.
The goal expressed in Article 2, paragraph l(a), of the Paris Agreement ("the
temperature goal") is of primary importance in determining, for the purposes of the
Paris Agreement, the degree of warming that constitutes dangerous anthropogenic
interference with the climate system. As part of the outcome of the first global stocktake
in 2023, the Parties to the Paris Agreement resolved to pursue efforts to limit the
temperature increase to 1.5 °C. 53
... Article 4 calibrates the Parties' discretion to determine their level of contribution and
on the objectives and measures to pursue in three ways.
First, good faith interpretation and application of Article 4, paragraph 2, in light of its
object and purpose, requires that the [National Determined Contributions] and its
implementation must be faithful to the long-term temperature goal of the Paris
Agreement under Article 2, and the aims of Article 4, paragraph 1, namely the global
50 Written Statement of Latvia (19 March 2024) <https://www.icj-cij.org/sites/default/files/caserelated/
187/187-20240319-wri-Ol-OO-en.pdf> paras 18, 28-32.
51 Paris Agreement (n 17) art 2(1).
52 United Nations Framework Convention on Climate Change (adopted 9 May 1992, entry into force 21
March 1994) 1771 UNTS 107 (signed by Latvia on 11 June 1992, ratified on 23 March 1995) art 2(1)
("Objective").
53 'Outcome' (n 22) [4]; see also, ibid [ 191 ], which launched the Roadmap to 1.5 °C.
9
peaking of GHG emissions as soon as possible and their rapid reduction thereafter.54
The object of climate change mitigation under Article 4, paragraph 1, is "to achieve the
long-term temperature goal set out in Article 2". 55 The mitigation regime established
by Article 4 entails a continuing, long-term approach to mitigation, based on
progressively greater mitigation efforts over time. The aim of the provision is that the
mitigation efforts of the Parties acting under Article 4 will achieve "global peaking" of
GHG emissions "as soon as possible" and "rapid reductions" in emissions thereafter,
so as to achieve a balance between anthropogenic emissions by sources and removals
by sinks of GHG in the second half of this century. 56 It has been noted in scholarship
that good faith performance of Article 4, paragraph 2, requires that measures to
implement an NDC must be faithful to the objectives set out in the NDC.57
Secondly, the obligations under Article 4, paragraph 2, have a procedural character.
Parties must act with reasonable diligence in preparing and pursuing the
implementation of their NDCs to ensure that the objectives of the Paris Agreement are
met.58 The due diligence standard is informed by the "highest possible ambition",
progression over time and differentiation,59 as noted in Article 4, paragraphs 3 and 4.60
Thirdly, Article 4 also provides for several procedural obligations regarding
preparation, communication, maintenance, and implementation of NDCs. These
obligations are expressed in Article 4, paragraphs 8 and 9 (to be read together with
Article 14, paragraph 3, and Article 4, paragraph 15). Under Article 4, paragraph 8,
Parties are obliged to provide "the information necessary for clarity, transparency and
understanding in accordance with decision l/CP.21 and any relevant decisions of the
Conference of the Parties serving as the meeting of the Parties to this Agreement
[CMA]".61 Decision 4, CMA.1 sets mandatory requirements for the provision of such
54 Oil Platforms (Islamic Republic of Iran v. United States of America) (Preliminary Objections) [1996]
ICJ Rep 803 [28].
55 Paris Agreement (n 17) art 4(1).
56 Ibid.
51 D Bodansky, J Bnmnee and L Rajamani (eds), International Climate Change Law (OUP 2017) eh 4; B
Mayer, International Law Obligations on Climate Change Mitigation (OUP 2022) 231.
58 C Voigt, 'The Paris Agreement: What Is the Standard of Conduct for Parties?' (2016) 18 QIL 17, 21. The
principle of due diligence is examined in more detail ... at Sub-section C.i [of the Written Statement].
59 Ibid; also B Mayer, International Law Obligations on Climate Change Mitigation (OUP 2022) 55-56.
60 These provisions, while not creating binding obligations on their own, L Rajamani, 'The 2015 Paris
Agreement: Interplay Between Hard, Soft, and Non-Obligations' (2016) 28 Journal of Environmental Law 337,
354-355, may be taken into account in interpretation and application, Pulp Mills on the River Uruguay (Argentina
v. Uruguay) (Judgment) [2010] ICJ Rep 14 [62]; Whaling in the Antarctic (Australia v. Japan: New Zealand
Intervening) (Judgment) [2014] ICJ Rep 226 [83], [137].
61 Decision l/CP.21, FCCC/CP/2015/L.9 [27], which must be understood together with the transparency
framework, see ... at [Section III.A.] (v) [of the Written Statement].
information.62 More generally, the implementation of the obligations under Article 4,
paragraph 2, must be understood in light of the institutional framework developed by
the COP and CMA.
Finally, the obligations under Article 4, paragraph 2, operate in conjunction with the
provisions concerning sinks and reservoirs under Article 5 and Article 6 on voluntary
cooperation. Article 5 does not establish a new obligation but encourages further pursuit
of the obligation relating to sinks and reservoirs established in Article 4, paragraph
(l)(d), of the UNFCCC. The implementation of this obligation occurs primarily in
accordance with the framework on Reducing emissions from deforestation and forest
degradation in developing countries (REDD-plus).63
Respectfully,
62 Decision 4, CMA. l, 'Further guidance in relation to the mitigation section of decision l/CP.21' (adopted
26th Plenary Meeting, 15 December 2018) FCCC/PA/CMA/2018/3/ Add. I ( 19 March 2019) [7], and Annex I [ 6][
7].
63 Decision 1/CP. I 9, 'Further Advancing the Durban' (adopted 10th Plenary Meeting, 23 November 2013)
FCCC/CP/2013/10/Add. l (31 January 2014).
Written reply of Latvia to the question put by Judge Tladi at the end of the hearing held on 13 December 2024