Omission in climate action as an international wrongful act, recognizes the UN
On May 20, 2026, the General Assembly of the United Nations ("UN") adopted Resolution A/RES/80/263 ("Resolution"), entitled "Advisory opinion of the International Court of Justice on the obligations of States in respect of climate change", which endorsed the Advisory Opinion of the International Court of Justice ("ICJ") on the obligations of Nation-States in respect of climate change, at which time it was recognized that international treaties on climate change impose legally binding obligations aimed at the protection of the climate system and the environment against anthropogenic greenhouse gas emissions[1].
That is, in the understanding of the UN, compliance with climate commitments assumed by States does not constitute a mere public policy option, but involves legal obligations arising from international law.
Although the Resolution does not, in itself, create new binding obligations, it confers institutional support to the understanding of the ICJ and reinforces the need for States to adopt effective measures to fulfill their climate commitments. In this context, insufficient measures or state omissions, to be assessed according to the specific circumstances, may constitute a violation of international obligations and give rise to the accountability of the Member State.
Prior to the Resolution, it was already legally possible to hold a State internationally accountable for omission, since the general regime of international responsibility admits accountability for the violation of obligations arising from both actions and state omissions[2]. The specific difficulty lay in defining how the international framework would apply to the climate obligations of States, given the multiplicity of normative sources, the cumulative nature of emissions, and the different state conduct and duties related to the climate phenomenon.
Furthermore, in the climate context, there was a controversy as to the extent to which the rules set forth in the United Nations Framework Convention on Climate Change and the Paris Agreement should be considered a self-contained regime sufficient to govern the obligations of States, displacing or limiting the application of general rules of international law and other obligations related to environmental protection and human rights[3].
The Advisory Opinion of the ICJ clarified this controversy by rejecting the interpretation that climate treaties would constitute a closed regime capable of generally excluding the application of other international norms. The Court recognized that the climate obligations of States must be analyzed in conjunction with other international sources and duties, including the duty to prevent significant environmental harm, the duty of cooperation, and human rights norms, in addition to observance of principles such as equity, sustainable development, precaution, and common responsibilities[4].
In practice, the new Resolution reinforces climate duties and clarifies the possibilities of holding States accountable for failures in addressing climate change. The ICJ recognized that the obligation of States to regulate the activities of private actors is associated with the duty of due diligence, such that the failure to adopt measures — regulatory and legislative — as well as to effectively monitor and implement measures, may be considered a failure in the exercise of this duty of due diligence.
Indeed, the Advisory Opinion of the ICJ strengthens the legal basis for questioning the conduct of States in addressing climate change. In Brazil, this movement is directly related to the implementation of the Climate Plan and its sectoral plans, which establish guidelines and measures for the reduction of emissions across the various sectors of the economy. Following the recognition by the ICJ that state omissions may give rise to international accountability, potential deficiencies in the formulation, implementation, or execution of such measures become more susceptible to legal challenges and climate litigation.
This reinforcement of state obligations also tends to drive the improvement of domestic regulation applicable to economic activities, such that the implementation of the climate agenda may result in the creation of new compliance obligations and the increase of regulatory costs for companies operating in sectors subject to emissions reduction targets.
Such effects may also reach environmental licensing, particularly of projects and activities with greater emission potential or vulnerability to the effects of climate change, which may become, increasingly, subject, in accordance with applicable legislation and the evolution of regulation, to more stringent requirements related to emissions measurement, climate risk assessment, mitigation and adaptation measures, resilience, and monitoring. Thus, anticipation of new regulatory requirements and adequate documentation of mitigation, monitoring, and climate risk management measures tend to assume increasing importance.
In this scenario, the UN Resolution consolidates a broader legal parameter for the conduct of States in climate matters and reinforces the need for the commitments assumed to be translated into concrete measures of prevention, control, regulation, and oversight. In Brazil, this understanding is added to a climate and regulatory agenda that is already under development, albeit at a slow pace, but which tends to accelerate with the improvement of existing norms and the mechanisms aimed at their implementation. For companies, especially those subject to greater climate and regulatory exposure, the process of legislative and regulatory evolution may signify greater legal certainty, in order to consolidate practices that address, from the outset, the potential impacts on their operations and investments.
Bibliography
UNITED NATIONS. General Assembly. Advisory opinion of the International Court of Justice on the obligations of States in respect of climate change. A/79/979. New York: United Nations, 2025. Available at: https://documents.un.org/doc/undoc/gen/n25/204/48/pdf/n2520448.pdf. Accessed on: Sep. 11, 2026.
UNITED NATIONS. General Assembly. Resolution 80/263. A/RES/80/263. New York: United Nations, 2026. Available at: https://docs.un.org/en/A/RES/80/263. Accessed on: Sep. 11, 2026.
UNITED NATIONS. International Law Commission. Responsibility of States for internationally wrongful acts, 2001. New York: United Nations, 2001. Available at: https://legal.un.org/ilc/texts/instruments/english/draft_articles/9_6_2001.pdf. Accessed on: Sep. 11, 2026.
INTERNATIONAL LAW COMMISSION. Draft articles on international responsibility of States. Translation. [S. l.]: Ius Gentium, Federal University of Santa Catarina, 2015. Available at: https://iusgentium.ufsc.br/wp-content/uploads/2015/09/Projeto-da-CDI-sobre-Responsabilidade-Internacional-dos-Estados.pdf. Accessed on: Sep. 11, 2026.
[1] Calls upon all States to comply with their respective obligations under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic greenhouse gas emissions, as identified by the Court. UNITED NATIONS. Resolution A/RES/80/263. New York: United Nations General Assembly, 2025. Available at: <https://docs.un.org/en/A/RES/80/263>. Accessed on: Sep. 11, 2026.
[2]Pursuant to Art. 2 of the Articles on Responsibility of States for Internationally Wrongful Acts, "There is an internationally wrongful act of a State when conduct consisting of an action or omission". INTERNATIONAL LAW COMMISSION. Draft Articles on Responsibility of States for Internationally Wrongful Acts. New York: United Nations, 2001. Available at: <https://legal.un.org/ilc/texts/instruments/english/draft_articles/9_6_2001.pdf>. Accessed on: Sep. 11, 2026.
[3]In this regard, the ICJ concluded that the treaties on climate change do not constitute the only applicable law to the climate obligations of States and that the principle of lex specialis does not imply the general exclusion of other rules of international law (INTERNATIONAL COURT OF JUSTICE. Advisory Opinion on the Obligations of States in Respect of Climate Change, § 171. Available at: <https://documents.un.org/doc/undoc/gen/n25/204/48/pdf/n2520448.pdf>. Accessed on: Sep. 11, 2026).
[4]The Resolution recognized the relevance, as applicable, of various international norms relating to climate change, including the Charter of the United Nations, the UNFCCC, the Kyoto Protocol, the Paris Agreement, the United Nations Convention on the Law of the Sea, the Vienna Convention for the Protection of the Ozone Layer, the Montreal Protocol, the Convention on Biological Diversity, and the United Nations Convention to Combat Desertification. UNITED NATIONS. Resolution A/RES/80/263. New York: United Nations General Assembly, 2026. Available at: <https://docs.un.org/en/A/RES/80/263>. Accessed on: Sep. 11, 2026.
