Brazil

Public International Law and Climate Change

Introduction

The public international regime aimed at regulating States’ obligations related to climate change had its main milestones since 1992 and has presented recent paradigmatic advances since the United Nations Framework Convention on Climate Change (“UNFCCC”), through the Kyoto Protocol and culminating in the Paris Agreement.

In relation to this timeframe, it is possible to observe both a transition from a centralized model to a polycentric approach, which seeks to reconcile the interests of developed and developing countries, and an increasing convergence of the public international law regime on the environment and climate change with the international human rights law regime.

In this sense, the public international law regime is based on legal principles that are especially relevant to the Brazilian perspective, such as (i) common but differentiated responsibilities, (ii) sustainable development, (iii) progressivity of ambition (prohibition of retrogression), (iv) and the principles of precaution and prevention. This relevance is in line with the principles that govern Brazil’s international relations, as established in Article 4 of the Federal Constitution, such as cooperation among peoples for the progress of humanity and the prevalence of human rights. In addition, paragraphs 2 and 3 of Article 5 reinforce the integration of international human rights treaties into the Brazilian legal system, which strengthens the Brazilian State’s commitment to international climate commitments as further explained.

As relevant milestones of public international climate change law from a Brazilian perspective, it is important to mention the United Nations General Assembly (“UN/GA”) Resolution No. 76/300, which recognizes the right to a clean, healthy and sustainable environment as a human right, and the recent advisory opinions issued by the International Court of Justice[1] (“ICJ”) and the Inter-American Court of Human Rights[2] (“IACtHR”), which consolidate States’ legal obligations related to climate change. The way in which Brazil internalizes and applies international climate law is also relevant, with emphasis on the supra-legal hierarchic status of the environmental treaties ratified by Brazil and the role of the Brazilian Federal Supreme Court (“STF”) in climate protection.

• Brazil has internalized the UNFCCC and the Paris Agreement, both of which have supra-legal status over ordinary legislation and shall bind its interpretation, as a consequence of the recognition by the STF in ADPF 708 that environmental and climate treaties should be read as kinds of human rights treaties in light of case law, imposing similar implementation duties on the Brazilian State.
• The principle of common but differentiated responsibilities is central to promoting equality between developed and developing countries in meeting climate change related obligations.
• UN/GA Resolution 76/300 recognizes the right to a healthy environment as a human right, reinforcing the integration between human rights law and environmental law (which includes the climate) regimes.
• The advisory opinions of the IACtHR and the ICJ in 2025 recognize that States have clear and binding legal obligations to protect the climate system and human rights in the context of climate change. These obligations include the duties of prevention, cooperation and reparation, as well as the application of the precautionary principle, which requires early action in the face of environmental risks even in the absence of absolute scientific certainty. The ICJ reinforces that these principles are fundamental to avoiding irreversible damage to the climate and ensuring the protection of vulnerable populations and future generations.
• International and national case law points to the consolidation of a new climate legal framework, with a focus on State accountability and the protection of vulnerable populations and future generations. Understanding these developments is of direct practical significance for legal practitioners advising on climate-related risks, compliance, and corporate obligations.

How Public International Law Addresses Climate Change

Evolution of the international climate change regime

The initial milestone for the international regime dedicated exclusively to tackling climate change is the celebration of the UNFCCC during the 1992 “Rio Conference”, also known as the “Earth Summit”. The UNFCCC is considered a fundamental step in the evolution of the international regime for the protection of the environment inaugurated in 1972, with the “Stockholm Conference” and the institution of the United Nations Environment Programme (“UNEP”).

It is also worth noting that the UNFCCC was not the first measure adopted by the UN on climate change. As early as 1979, the First World Climate Conference, organized by the World Meteorological Organization, had brought together experts and governments to discuss the risks of global warming. Subsequently, in 1988, the UN established the Intergovernmental Panel on Climate Change (“IPCC”) with the objective of producing quinquennial reports on the matter of climate change. It is noteworthy that the first IPCC report, presented in 1990, played a decisive role in the creation of the UNFCCC. In addition, prior to the UNFCCC, States had already signed the 1985 Vienna Convention and the 1987 Montreal Protocol aimed at tackling the emission of air pollution – especially the emission of chlorofluorocarbons (“CFCs”) – and the depletion of the ozone layer.

Another characteristic of the UNFCCC is that it establishes a binding regime. Thus, although it does not impose emissions reduction targets on signatory States, the UNFCCC establishes among its substantive obligations the duties to formulate, implement and regularly update national or regional programs aimed at mitigating climate change (Article 4, 1, b). On the other hand, among the procedural obligations, signatories would be obliged to develop and periodically update their national inventories of greenhouse gases (“GHG”) not controlled by the Montreal Protocol (Article 4, 1, a). The UNFCCC has also established the Conference of the Parties (“COP”) as its supreme governing body, responsible for monitoring its implementation, as well as acting as a permanent forum for negotiations within its framework (Article 7).

It is worth noting that the UNFCCC is also considered the treaty responsible for reconciling the interests of developed and developing countries through the principle of common but differentiated responsibilities (Article 3, 1). Based on this principle, it imposes a series of obligations specifically aimed at developed countries (listed in Annex I), as those would be responsible for the historical emissions of GHG. Among these obligations are the elaboration of national climate change policies and to have leadership in the process of mitigating emissions (Article 4, 2).

Later, in 1997, the Kyoto Protocol was signed with the aim of establishing specific GHG emissions mitigation duties for developed countries and those “in transition to a market economy” (nowadays known as “developing countries”) – listed in Annex B. For its first commitment period (2008-2012), the Kyoto Protocol set emissions reduction targets of an average of 5% compared to 1990 levels (Article 3 and Annex B). The Kyoto Protocol established a compliance mechanism in 2005, with Decision 27/CMP.1, with the objective of ensuring the enforcement of such targets.

The Kyoto Protocol also had flexibility mechanisms aimed at (i) assisting signatory States in meeting emissions reduction targets and (ii) stimulating the sustainable development of developing countries. These mechanisms were: the emissions market (“ET”); the Clean Development Mechanism (“CDM”) and Joint Implementation (“JI”). Thus, although developing countries do not have emissions reduction obligations, they could actively contribute to meeting the targets established by the Kyoto Protocol through the CDM (Article 12) or the JI (Article 6). In general terms, the CDM allowed developing countries to implement emissions reduction projects with the objective of issuing Certified Emission Reduction credits (“CERs”) equivalent to 1 tCO2e that could be used by developed countries to meet their respective targets. The JI allowed Annex B countries to jointly implement projects in their territories aimed at issuing Emission Reduction Units (“ERU”), which could also be accounted for the purpose of meeting the Protocol’s targets.

However, despite the flexibility mechanisms, the effectiveness of the Kyoto Protocol is debatable. On the one hand, there are those who consider the Protocol a failure because the USA, the largest emitter of GHGs at the time, failed to ratify it, and several participants withdrew from the Protocol during its negotiations, such as Canada. On the other hand, there are those who consider that the Protocol brought significant advances in the reduction of GHG emissions for the signatory States.

From 2009 onwards, with the Copenhagen COP, there was a real paradigm shift in relation to the framework inaugurated by the Kyoto Protocol. At this COP, the parties decided to abandon the architecture of the Kyoto Protocol in favor of a more flexible approach in which countries would define their own goals and actions and then register them within the framework of the UNFCCC – characterized as a “bottom-up” approach.

The Copenhagen COP is also considered the starting point of a trend of decentralization of the international climate change regime characterized as “hybrid multilateralism”, composed simultaneously of voluntary norms and soft law and binding norms and counting with States and non-State agents aimed at confronting climate change. This analysis is directly related to discussions that describe responses to climate change as “polycentric measures”, intensified with the formulation and entry into force of the Paris Agreement.

In 2015, the Paris Agreement was signed. With the Agreement, three main objectives were established for the international climate regime: (i) containment of the increase in global temperature to well below 2ºC, with efforts to limit it to 1.5ºC, in relation to pre-industrial levels; (ii) promotion of increased capacity to adapt to the adverse impacts of climate change; and (iii) promotion of financial flows consistent with the path towards low-carbon and climate-resilient development – i.e. mitigation, adaptation and financing (Article 2).

Aiming to address the mitigation axis, the Paris Agreement establishes the instrument of Nationally Determined Contributions (“NDCs”). NDCs represent the emissions reduction commitments adopted by the Parties, which differ from the Kyoto Protocol because (a) they are determined at the national level, rather than negotiated at the international level; (b) NDCs should be publicly registered by the Parties themselves, rather than in the annexes to the Agreement; and (c) all signatory States are equally subject to the drafting and submission of NDCs.[3]

The Paris Agreement is also innovative as it establishes obligations regarding the adaptation axis, imposing the obligation on States to engage in adaptation planning processes, as well as to implement actions towards it, such as the development or enhancement of plans, policies and/or relevant contributions – as well as the setting of a “global adaptation goal” (Article 7). Adaptation was also included in the scope of metrics evaluated by the “Global Stocktake” (Article 14) and in the determination of parity in the allocation of financial resources dedicated to mitigation and adaptation (Article 9.4).

The third pillar of the Paris Agreement concerns directing funds from developed countries for mitigation and adaptation measures (Article 9.1), which is not properly an innovation since the UNFCCC determines developed countries’ obligation to provide financial resources towards the fulfillment of obligations of developing countries (Article 4, paragraph 3). This topic is considered one of the most disputed within the UNFCCC due to the financial gap between developed and developing countries and the consistent refusal by developed countries to institute new commitments and expand the group of donors.

Even though it is not shielded from some criticism, the Paris Agreement provides significant obligations around climate financing such as the obligation imposed to developed countries to submit communications containing qualitative and quantitative information on the respective allocation of resources (Article 9.5).

Based on this panorama, despite consisting mainly of recommendations, the Paris Agreement is considered a multilateral binding instrument of international law and applicable to all Parties under the principle of common but differentiated responsibilities set forth in the UNFCCC.

Relevant principles of the international climate change law regime

In view of this brief overview of the evolution of public international law on climate change and based on the main conventions and treaties in force at the time of the writing of this chapter, the following principles are especially pertinent to the Brazilian perspective:

Common but differentiated responsibilities: Incorporated as one of the principles of the UNFCCC to mandate States to implement measures aimed at protecting the climate for the benefit of present and future generations, according to the difference in their responsibilities and respective capacities (Article 3.1). As pointed out by the text of the Convention itself, the principle implies the duty of developed countries to take the lead in tackling climate change. In addition, it is based on this principle that the Convention differentiates States Parties and assigns a series of obligations to developed countries (Article 4). This principle is considered one of the pillars of “climate law” because it recognizes the historical inequality between States in terms of GHG emissions and establishes a normative guideline strongly influenced by climate justice.

Sustainable development: Defined as “a process of change in which the exploitation of resources, the direction of investments, the orientation of technological development, and institutional change are made consistent with future as well as present needs.” The principle of sustainable development has been incorporated into the text of the UNFCCC (Article 3.4) to ensure that climate change mitigation measures are proportionate to the specific conditions of States Parties and are part of national development programmes. In addition, the Paris Agreement is also permeated by the idea of sustainable development throughout its text (Articles 2.1; 4.1; 6; 7.1; 8.1; and 10.5). According to the preamble of the Convention itself, the principle of sustainable development is also especially relevant for Brazil, as it guarantees developing countries the possibility of increasing their GHG emissions in order to meet their social and development needs.

Progressiveness of ambition: As established by the Paris Agreement, the legal regime for climate protection must progressively advance, and the NDCs themselves must contain ever-increasing ambition (Article 3 and Article 4.3). Conversely, therefore, this principle imposes the prohibition of setbacks in the climate field.

Human rights, the environment and climate change

On July 28, 2022, the UN/GA adopted Resolution 76/300,[4] which recognizes the right to a clean and sustainable environment as a human right, also considered being closely related to and essential for the fulfillment of other human rights recognized in international law. It also recognizes that its protection requires the implementation of multilateral agreements on environmental law and urges States, international organizations, businesses and other relevant stakeholders to adopt policies, strengthen international cooperation, expand capacity building, intensify efforts and share best practices to ensure its enjoyment by all.

Although the Resolution does not directly create rights and obligations, it contributes to the interpretation of other human rights obligations[5], to the formation of customary norms, legitimization of national legislative processes, and may serve as a basis for judicial decisions and public policies. In addition, it promotes integration between environmental protection and human rights legal regimes, reinforcing the rights-based approach in global environmental governance.

From this perspective, by recognizing the right to a clean, healthy and sustainable environment as a human right, Resolution 76/300 became a guiding framework for normative and interpretative production in the UN system. Since then, special rapporteurs have begun to consolidate material parameters, such as: the Special Rapporteur on the Right to Development, Surya Deva, outlined a framework for climate justice (setting the pillars of mitigation, adaptation, reparation and transformation) and State obligations on loss and damage; the Special Rapporteur on climate change, Elisa Morgera, issued a series of thematic reports on energy transition and human rights; and the Special Rapporteur on the human right to a clean, healthy and sustainable environment, Astrid Puentes Riaño, advanced guidelines on the ocean and human rights anchored in this right. These reports functioned as a normative and argumentative basis for the ICJ’s Advisory Opinion on State Obligations on Climate Change, for IACtHR OC No. 32 on the climate emergency, and, at the domestic level, for the framework adopted in ADPF 708, reinforcing the reading of climate commitments as human rights obligations.

International Precedents on Climate Change

Considering that in 2025 international courts issued paradigmatic opinions for the legal regime of climate protection, it is worth briefly discussing some of these opinions that are especially relevant to the Brazilian scenario and that of other developing countries. The IACtHR and ICJ advisory opinions discussed below represent distinct but convergent contributions: the IACtHR applies a human-rights lens within the Inter-American system, while the ICJ provides a universal framework under general international law. Together, they reinforce the legal nature of States’ climate obligations and have significant implications for national implementation.

IACHR: OC 32/2025

The first opinion to highlight is Advisory Opinion (“OC”) No. 32/25, jointly requested by the States of Chile and Colombia to the IACtHR, based on Article 64.1 of the American Convention on Human Rights (American Convention). The request sought to clarify the scope of the obligations of the American States, in light of the American Convention and other relevant regional treaties, in relation to the causes and consequences of the climate emergency, especially with regard to the protection of substantive human rights, procedural rights, and duties towards groups in situations of vulnerability.

The IACtHR accepted the request, recognizing the relevance of the matter and the existence of a regional and global legal interest in defining State obligations in the face of the impacts of the climate crisis on human rights. It also stressed the relevance of the consultation, which was not to be confused with a contentious case or an internal political issue. In addition, the IACtHR recognized the climate emergency as a concrete, current, and future threat to human rights, inserted in the broader context of the “triple planetary crisis,” composed of climate change, biodiversity loss, and pollution. At the same time, the Court affirmed the jus cogens nature of the obligation not to cause irreversible damage to the climate and the environment, qualifying it as a mandatory norm of international law, non-derogable and enforceable erga omnes (OC-32/25).

Based on this, the opinion was structured in three analytical axes: (i) obligations related to substantive rights; (ii) procedural obligations; and (iii) obligations in relation to groups in situations of vulnerability. Among the main foundations of the advisory opinion, the following stand out:

• The duty of reinforced prevention (climate due diligence): States must adopt all necessary measures, quickly and effectively, to prevent environmental and climate damage that may violate human rights protected by the American Convention.
• Recognition of the right to a healthy environment as an autonomous right: Based on a previous advisory opinion (OC-23/17), the Court reiterated that the right to a healthy environment is fully enforceable in the inter-American system, is affected by climate change and should guide State action.
• The prohibition of retrogression and the requirement of progressivity: States have the duty to advance, without unjustified setbacks, in the implementation of environmental and climate measures, including normative ones. Omission, regressivity, or unwarranted delay may constitute violations of the American Convention.
• The obligation of domestic normative adequacy: The Court has stated that the legal system of each State must incorporate norms that enable the effective implementation of climate commitments, including obligations imposed on individuals and companies, in light of Articles 1.1, 2, and 26 of the American Convention. This holding is of particular relevance to the private sector, as it establishes a basis for domestic legislation requiring corporate climate due diligence, emissions reporting, and supply chain accountability.
• The duty of international climate cooperation: States must cooperate in good faith in responding to the climate crisis, including with the mobilization of financial resources and technology transfer, in accordance with customary international law and the UN Charter.
• The rights of access to information, public participation, and environmental justice: The Court reaffirmed that these rights are essential for democratic climate governance and must be respected to the fullest extent, including with specific measures to ensure access by vulnerable groups, in line with regional instruments such as the Escazú Agreement (2018), which consolidates these rights in Latin America and the Caribbean.
• The enhanced protection of vulnerable populations: Children, indigenous peoples, Afro-descendant communities, environmental defenders, migrants, and inhabitants of particularly sensitive territories (such as islands and Amazonian areas) must receive special attention in State climate measures, including differentiated guarantees of adaptation, participation, and territorial protection.
• Recognition of Nature as a subject of rights: The Court affirmed that, in the context of the climate emergency, Nature (ecosystems and their components) is a subject of rights, which reinforces the State’s duties to protect, conserve and, when appropriate, restore ecological integrity, guided by the best available science and the interdependence between human rights and the environment.

It is worth noting that OC No. 32/2025 was widely celebrated by civil society organizations, academics, and climate activists. An example of this is that it has been considered unprecedented and extremely relevant for the construction of an “inter-American climate law”, bringing the standards of the Inter-American System closer to those already affirmed in instances such as the European Court of Human Rights and ITLOS.

AIDA (“Inter-American Association for the Defense of the Environment”) evaluated the opinion as historic, emphasizing that OC-32 establishes specific legal obligations for mitigation and adaptation to the climate crisis, protecting both people and Nature. The organization celebrated the incorporation of intersectional perspectives and the advancement of the recognition of Nature as a subject of rights. The political impact of the decision was also highlighted: OC-32 provides a solid legal basis for strategic actions by civil society and enhances climate litigation at the regional level, strengthening the accountability of States.

In sum, OC No. 32/2025 provides a comprehensive rights-based framework for climate action in the Americas. Its holdings on corporate obligations, vulnerable populations, and Nature as a subject of rights have direct implications for the domestic legal orders of all OAS member states, including Brazil, as discussed in Section 5 below.

ICJ: OC of 23 July 2025

On July 23, 2025, the ICJ published its first advisory opinion on climate change,[6] in response to the request made by the UN/GA through Resolution 77/276.[7] The request was made on the basis of Article 96 of the UN Charter and Article 65 of the Statute of the ICJ, with the aim of clarifying the two main questions:

What are the obligations of States under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of GHGs for States and for present and future generations;

What are the legal consequences under these obligations for States where they, by their acts and omissions, have caused significant harm to the climate system and other parts of the environment, with respect to: (i) States, including, in particular, small island developing States, which due to their geographical circumstances and level of development, are injured or specially affected by or are particularly vulnerable to the adverse effects of climate change?; (ii) Peoples and individuals of the present and future generations affected by the adverse effects of climate change?”.

In its response, the ICJ identified a comprehensive set of legal obligations derived from different sources of public international law.[8]

At the conventional level, the ICJ highlighted the main climate treaties: the UNFCCC, the Kyoto Protocol and the Paris Agreement. The Court stated that the UNFCCC establishes general obligations of mitigation, adaptation and cooperation, based on the principle of common but differentiated responsibilities. As for the Kyoto Protocol, the Court recognizes the imposition of binding emission reduction targets for countries listed in its annex. Finally, with regard to the Paris Agreement, there is the establishment of conduct and result obligations, such as the formulation and maintenance of progressive and ambitious NDCs, compatible with the goal of limiting global warming to 1.5ºC.

The ICJ reaffirmed the duty to prevent significant environmental damage, including to the climate system, based on the principle of prevention and the standard of conduct of due diligence. This duty includes States taking appropriate measures, conducting environmental impact assessments, and taking into account the best available science. The Court also recognized the duty of international cooperation as a fundamental legal obligation, especially in the face of the global and cumulative nature of climate change.

The ICJ also examined other relevant environmental treaties, such as the Vienna Convention and the Montreal Protocol (protection of the atmosphere and ozone layer), the Convention on Biological Diversity,[9] and the Convention to Combat Desertification[10]. In addition, in the field of the law of the sea, the Court recognized that GHG emissions can be characterized as marine pollution and that States have obligations of prevention, cooperation and impact assessment under UNCLOS.[11]

In convergence, ITLOS, in an Advisory Opinion of 21 May 2024 (Case No. 31), stated that anthropogenic GHG emissions absorbed by the oceans constitute “pollution of the marine environment” under UNCLOS and that States should take all necessary measures – based on the best available science, environmental impact assessments and international cooperation – to prevent, reduce and control such impacts.

With regard to human rights, the ICJ stated that the adverse effects of climate change compromise the exercise of several fundamental rights, such as the right to life, health, housing and food. Resolution 76/300 concludes that States have a duty to adopt concrete measures to protect human rights in the face of the climate crisis, including in relation to vulnerable populations and future generations.

Subsequently, in relation to the second question submitted to the ICJ, the Court stated that non-compliance with the obligations identified above constitutes an internationally unlawful act. It is possible to highlight the following points of the answer:

• International responsibility of the State, based on the general rules of international law, including in situations of multiple States responsible for cumulative conduct;
• States are responsible for omissions or failures to regulate activities under their jurisdiction, including those of private actors, as long as there is a direct and certain causal link between the unlawful act and the climate damage. This finding is particularly significant for private-sector actors, as it affirms that States bear international responsibility for failing to regulate corporate conduct that contributes to climate harm, thereby reinforcing the legal basis for domestic regulatory frameworks targeting private emissions and climate-related due diligence;
• Erga omnes nature of climate obligations, allowing any State to invoke the international responsibility of another State, even without being directly harmed;
• Specific legal consequences: duty of termination, guarantees of non-repetition and duty of reparation, which may include forms of restitution, compensation and satisfaction.

In view of the above, the ICJ concluded that States have clear and binding legal obligations to protect the climate system and that the violation of these obligations makes them liable to international accountability. In addition, the Court recognized that the climate crisis requires collective, interdisciplinary, and urgent action, which is not limited to strictly legal responses and presumes the articulation of public policies, climate science, technological innovation, financing, and international cooperation.

The publication of the ICJ Advisory Opinion was a watershed moment in international environmental law. The decision represents the consolidation of a legal framework by stating that the climate obligations of States are not mere political promises, but rather enforceable legal duties, the violation of which may constitute an international wrongdoing.

The international community also highlighted the importance of the decision by recognizing that NDCs are not voluntary commitments, but rather legal obligations of result that should reflect the highest possible ambition of each State, considering its historical capabilities and responsibilities. It is also worth noting that the ICJ was clear in stating that the mere presentation of NDCs is not enough: their content must be compatible with the goal of limiting global warming to 1.5°C, as established in the Paris Agreement.[12]

Finally, the decision was interpreted as a call to action for large emitters and emerging countries, which will no longer be able to justify their inaction based on the omission of others. The Court made clear that all States have obligations proportionate to their capabilities and responsibilities, and that the climate crisis requires coordinated, ambitious and legally grounded efforts. Notably, this framing may create tensions for developing countries such as Brazil, which must reconcile the principle of sustainable development — which permits increased GHG emissions to meet social and development needs — with the ICJ’s emphasis that NDC content must be compatible with the goal of limiting global warming to 1.5°C. In this sense, the 2025 Advisory Opinion is seen as a powerful instrument for international accountability and for strengthening global climate governance.

How the Brazilian regime incorporates public international climate change law

Having examined the key international instruments and the advisory opinions of the IACtHR and ICJ, this section turns to how Brazil has incorporated these public international climate law obligations into its domestic legal framework. The analysis focuses on constitutional integration, the supra-legal status of environmental treaties, and the STF’s role in affirming climate obligations as binding on the Brazilian State.

The Federal Constitution regulates the relationship between the domestic and international regimes. According to Article 5, paragraphs 2 and 3, the rights and guarantees expressed in the Constitution do not exclude others arising from the regime and international treaties to which Brazil is a signatory.

The UNFCCC was internalized in the Brazilian legal system through Legislative Decree No. 1/1994 and Decree No. 2,652/1998. The UNFCCC is one of the results of the 1992 Rio Conference, which also originated from the Convention on Biological Diversity, the Rio Declaration and Agenda 21.

The Paris Agreement is another milestone of international environmental and climate law that was internalized in the Brazilian legal system through Legislative Decree No. 140/2016  and Decree No. 9,073/2017. Like the UNFCCC, the Paris Agreement has a “supralegal” hierarchy – that is, it is above ordinary legislation, but below the Federal Constitution.

This hierarchical status was conferred by a decision of the STF in the judgment of ADPF 708, in which the Court understood that international treaties on the environment and climate should be considered as a kind of human rights treaties. It is worth noting that to establish this ruling, the STF followed the understanding established in the precedent RE 466.343/SP, judged in 2008, in which the Court recognized for the first time that international treaties on human rights have supra-legal stature.

ADPF 708 was filed in 2020 by several political parties challenging the Federal Government’s decision to withhold funding from the Climate Fund beginning in 2019. The lawsuit was upheld on July 4, 2022, when the STF ruled that the withholding of the financial contributions established by law for the Climate Fund violated both the Federal Constitution and the international commitments assumed by Brazil under environmental and climate treaties. This decision is considered paradigmatic of climate litigation in Brazil, as it was the first time the STF explicitly linked domestic budgetary obligations to international climate commitments.

In addition, Brazilian legislation incorporated a series of principles of the public international climate change regime, such as: precaution, prevention, citizen participation, sustainable development, and common but differentiated responsibilities (Law No. 12,187/2009, Article 3).[13]

It is also noteworthy that, as of the date of this article, Brazil has not yet ratified the Escazú Agreement (Regional Agreement on Access to Information, Public Participation and Access to Justice in Environmental Matters in Latin America and the Caribbean). While the IACtHR’s OC No. 32/2025 expressly references the Escazú Agreement as a regional instrument consolidating procedural environmental rights, Brazil’s non-ratification represents a gap in its domestic implementation of these procedural safeguards for climate governance. The Escazú Agreement bill has already been approved by the Brazilian House of Representatives, and is currently awaiting for approval by the Federal Senate under the nomination of Legislative Decree Project (“PDL”) No. 934/2025.

Finally, the Brazilian NDC establishes targets for the reduction of net GHG emissions between 59% and 67% by 2035, compared to 2005 levels. The NDC is directly aligned with the Climate Plan 2024-2035, which is the main national strategy to address climate change. The Climate Plan is structured on three pillars: mitigation, adaptation and Cross-Cutting Strategies for Climate Action — which are respectively structured into several sectorial plans. With the architecture provided by Climate Plan 2024-2035, it is expected that climate change to be addressed in an integrated manner, seeking to reduce the causes of global warming while preparing society and territories to become more resilient to its impacts, from the perspective of sustainable development and climate justice.[14]

In light of the foregoing, the Brazilian legal framework reflects a growing integration of international climate commitments into domestic law. The supra-legal status of environmental and climate treaties, the STF’s jurisprudence affirming climate obligations as human rights obligations, and the mandatory nature of NDCs as confirmed by the ICJ advisory opinion together create a robust normative architecture. As the Climate Plan’s implementation progresses and international climate jurisprudence continues to develop, legal practitioners should anticipate increased scrutiny of both state and private-sector compliance with these obligations.

[1] Brazil is a party to the Statute of the International Court of Justice, under the terms of the Charter of the United Nations, recognizing its authority in the interpretation of UN treaties, but has not recognized the mandatory jurisdiction of the Court provided for in Article 36, paragraph 2 of that Statute. Thus, any submission of the Brazilian State to the contentious jurisdiction of the ICJ depends on the express manifestation of consent, either by means of an arbitration clause in international treaties or by special agreement in each specific case.

[2] Brazil is a party to the Organization of the American States (“OAS”), has ratified the American Convention on Human Rights and its San Salvador Protocol and recognizes the jurisdiction of the IACtHR. In the judgment of RE 466.343/SP, STF has established the supra-legal nature of international human rights treaties, which are located hierarchically above ordinary legislation, consequently binding the interpretation and applicability of national legislation due to an interpretation of article 5, paragraph 3, of the FC under the principles set forth in the Constitutional text. For such reason, the rulings of the Inter-American Court regarding human rights obligations and its contents have been regularly incorporated into STF’s caselaw through what is called “conventionality control”, reaching not only human rights related rulings but also related to the environment and the climate.

[3] Bodansky, Daniel ‘The Paris Climate Change Agreement: A New Hope?’ (American Journal of International Law, 110 (2), 2016, p. 304) <https://doi.org/10.5305/amerjintelaw.110.2.0288> accessed May 26, 2025.

[4] ‘UN/GA Resolution No. 76/300’ <https://docs.un.org/en/A/RES/76/300> accessed on 27 July, 2025.

[5] Perruso, Camila ‘Le droit à un environment sain, propre et durable saisi par le droit international’ (2024) <https://www.conseil-constitutionnel.fr/publications/titre-vii/le-droit-a-un-environnement-sain-propre-et-durable-saisi-par-le-droit-international> accessed on 27 July, 2025.

[6] For more information on the PO from July 23, 2025 to: <https://www.icj-cij.org/case/187/advisory-opinions> accessed on July 27, 2025.

[7] For more information on A/RES/77/276 <https://docs.un.org/en/A/RES/77/276> accessed on 27 July, 2025.

[8] For the purposes of this §31 and in accordance with Article 38 of the ICJ Statute, the sources of public international law include: (i) treaty law (treaties); (ii) customary international law; (iii) general principles of law; and, as subsidiary means for determining rules, (iv) judicial decisions and (v) the doctrine of the most qualified publicists of the various nations.

[9] For more information on the Convention <https://www.cbd.int/> accessed on 27 July, 2025.

[10] For more information on the Convention <https://www.unccd.int/> accessed on 27 July, 2025.

[11] For more information on the Convention <https://www.imo.org/en/ourwork/legal/pages/unitednationsconventiononthelawofthesea.aspx> accessed on 27 July, 2025.

[12] IISD ‘Highlights and images for 23 July, 2025’ (IISD Earth Negotiations Bulletin, 2025) <https://enb.iisd.org/international-court-justice-advisory-opinion-climate-change-23Jul2025> accessed on 27 July, 2025.

[13] ‘Law No. 12.187/2009’ <https://www.planalto.gov.br/ccivil_03/_ato2007-2010/2009/lei/l12187.htm> accessed on 28 July, 2025.

[14] For more information on Plano Clima 2024-2035 <https://www.gov.br/mma/pt-br/composicao/smc/plano-clima> accessed on 20 April, 2026.