1. Introduction
International climate governance faces the challenge of transforming formal commitments into effective responses to the climate crisis. The intensification of climate change and its socio-environmental impacts demands mechanisms capable of fostering coordinated responses among States.
Beyond being an environmental problem, the climate crisis emerges as a central human rights issue. Its effects directly impact fundamental rights, such as life, health (external link), food, and access to an ecologically balanced environment, affecting vulnerable populations most acutely. In this context, international climate governance must be understood not only as a system of cooperation among States, but as an instrument for protecting human dignity on a global scale.
In this juncture, Viola (2008) distinguishes climate governance from climate governability, highlighting that the effectiveness of the international response to the climate crisis stems not merely from the signing of formal agreements, but from the concrete capacity of States to implement them, linking this capacity to the emerging concept of climate security.
Further, Gaetani (2023, p. 28) points out that the world is undergoing a political and economic transition marked by new geopolitical and environmental tensions, expanding risks and uncertainties in international relations. The United Nations Framework Convention on Climate Change (UNFCCC), adopted in 1992, established the foundations of global climate governance, differentiating States' obligations according to their level of development.
Subsequently, the Paris Agreement, adopted in 2015, introduced innovative instruments such as Nationally Determined Contributions (NDCs) and the Global Stocktake, a collective review mechanism designed to assess the progress of national efforts. The bottom-up model expanded state participation by allowing each country to determine its climate commitments. However, the outcomes of the Global Stocktake indicate that, even with the implementation of current NDCs, projected global warming remains between 2.1 °C and 2.8 °C—above the limits established by the agreement—highlighting the insufficient level of ambition of the targets.
Moreover, the voluntary nature of NDCs makes the climate regime dependent on the political will of national governments, which heightens its vulnerability to unilateral reversals. The withdrawal of the United States from the Paris Agreement at the beginning of President Donald Trump’s second term, in January 2025, illustrates this structural fragility.
Against this backdrop, this paper aims to analyze the role of Nationally Determined Contributions in international climate governance, investigating the extent to which this instrument contributes to addressing the global climate crisis and protecting human rights. Thus, the following research question is posed: to what extent are Nationally Determined Contributions effective as an instrument of international climate governance and human rights protection, particularly for populations vulnerable to the effects of the climate crisis?
2. NDCS AND INTERNATIONAL CLIMATE GOVERNANCE: INSTITUTIONAL ADVANCES AND STRUCTURAL FRAGILITIES
International climate governance has the UNFCCC as its primary institutional foundation, which established the commitment to stabilize greenhouse gas concentrations. Even so, the initial regime had limitations regarding the definition of concrete targets and implementation mechanisms.
In this context, the Paris Agreement, adopted in 2015, represents a milestone in the evolution of global climate governance by introducing a model of cooperation based on Nationally Determined Contributions (NDCs). In contrast to previous models structured around rigid and differentiated targets, the agreement adopted a decentralized logic in which each State determines its mitigation and adaptation commitments. Under Article 4 of the agreement, States must prepare, communicate, and maintain successive NDCs, which should reflect the highest possible ambition and be updated periodically.
This mechanism is complemented by transparency and international review instruments, such as the Global Stocktake, responsible for collectively assessing global progress toward climate goals. From this perspective, the adoption of NDCs has yielded significant positive effects on climate governance. First, the flexible model contributed to significantly broadening States' adherence to the international climate regime, enabling the participation of countries with varying levels of development and institutional capacities. Moreover, the flexibility of contributions allows commitments to be tailored to the economic, social, and technological realities of each country, fostering greater political feasibility in implementing targets.
Another relevant aspect is the promotion of international cooperation and the integration of climate policies at the domestic level. Recent initiatives, such as the Declaration on Information Integrity on Climate Change, presented at COP30 (INICIATIVA GLOBAL PELA INTEGRIDADE DA INFORMAÇÃO SOBRE MUDANÇA DO CLIMA, 2025), reinforce the importance of transparency, access to information, and social participation to strengthen global climate action and trust in environmental policies.
Despite these advances, the effectiveness of NDCs still faces major limitations. Among the main challenges is the lack of coercive compliance mechanisms, given that the Paris Agreement does not provide for formal sanctions against States that fail to achieve their targets. Thus, the system relies primarily on international pressure, transparency, and States' reputation as instruments to incentivize compliance with assumed commitments.
In parallel, current targets are insufficient to achieve the central objective of the agreement, which consists of holding the increase in global average temperature to well below 2 °C above pre-industrial levels Rose et al. (2017). This highlights a gap between the commitments declared by States and the level of ambition needed to effectively tackle the climate crisis. This limitation becomes even more evident from the outcomes of the first Global Stocktake of the Paris Agreement.
Rose et al. (2017) demonstrate, through simulations of regional emissions scenarios, that even the full implementation of NDCs by major emitters is insufficient to permanently reverse the warming trajectory, requiring a substantially broader and more ambitious mitigation effort after 2023 that also involves developing countries, in order for there to be a real chance of limiting temperature rise to 2 °C.
The collective assessment indicated that, even considering the full implementation of the NDCs currently submitted, the level of global ambition remains insufficient to limit the average temperature increase to 1.5 °C or even to well below 2 °C. The synthesis report on Nationally Determined Contributions indicates that projected global warming remains between 2.1 °C and 2.8 °C, above the limits established by the Paris Agreement.
Furthermore, projected global emissions for 2030 show an insignificant reduction compared to current levels, remaining far from what is necessary to limit temperature rise to 1.5 °C, identifying a significant emissions gap. These elements demonstrate that national commitments, while broadening participation and international cooperation, do not in themselves guarantee the effectiveness of the climate regime.
Added to this context, another factor that limits the effectiveness of NDCs is the strong dependence on the political will of national governments, which can alter economic and environmental priorities over time. This characteristic highlights the predominantly cooperative nature of the contemporary climate regime, in which the implementation of targets depends on the coordination among national policies, international pressure, and civil society participation.
In this scenario, it can be affirmed that the introduction of NDCs represented a significant institutional advance in international climate governance by broadening state participation and structuring a system for the periodic review of climate targets. However, the effectiveness of this mechanism remains conditioned upon the strengthening of transparency, monitoring, and international cooperation instruments, as well as an increased level of ambition in national contributions. Such structural vulnerability finds concrete illustration in the recent trajectory of the United States within the international climate regime.
This fragility is evident in the recent trajectory of the United States. In January 2025, on the first day of his second term, President Donald Trump signed an executive order withdrawing the United States from the Paris Agreement, repeating an identical gesture to that of his first administration in 2017, when the country had already abandoned the agreement before rejoining under the Biden administration. The reiteration of this move highlights, with uncommon precision, the systemic fragility of NDCs: in the absence of coercive mechanisms, compliance with climate commitments remains entirely subordinate to the alternation of domestic political power, capable of being reversed by a single executive act.
In January 2026, the United States went even further, withdrawing from the United Nations Framework Convention on Climate Change itself—the founding treaty of the entire international climate regime. In response, UNFCCC Executive Secretary Simon Stiell described the decision as "a colossal own goal" (AGÊNCIA BRASIL, 2026), warning that the American withdrawal from global climate cooperation would tend to harm the US economy, jobs, and the standard of living of American citizens as climate disasters intensify. Stiell reaffirmed, however, that the global transition to a low-carbon economy was declared irreversible by 194 countries at COP30, signaling that the international climate regime continues to advance regardless of the US position. This phenomenon, however, is not limited to the American context.
A similar phenomenon can be observed in Brazil. During the 2018 election campaign, then-presidential candidate Jair Bolsonaro went so far as to publicly threaten the country's withdrawal from the Paris Agreement, as reported by O Globo (2018), arguing that the treaty compromised national sovereignty over the Amazon and represented an obstacle to economic development. Although the withdrawal did not materialize after his election—partly due to pressure from agribusiness sectors concerned about international trade sanctions—the episode exposed an often underestimated dimension of the fragility of NDCs: the vulnerability of the climate regime stems not only from formal withdrawals, but also from the erosion of domestic implementation policies, which can occur silently and gradually over the course of a presidential term.
During the Bolsonaro administration, Brazil recorded a significant increase in deforestation rates accompanied by weaknesses in environmental enforcement, compromising, in practice, the commitments made by the country in its NDC, even though it formally remained a signatory to the Paris Agreement (OBSERVATÓRIO DO CLIMA, 2022). These cases, taken together, demonstrate that the effectiveness of NDCs depends not only on the formal adherence of states to the climate regime, but also on the consistency and continuity of national implementation policies—a dimension that the voluntary architecture of the Paris Agreement, by itself, is unable to guarantee.
3. THE HUMAN RIGHTS DIMENSION IN INTERNATIONAL CLIMATE GOVERNANCE
The intensification of climate change is not restricted to an environmental or economic challenge; it also constitutes a direct threat to the effectiveness of fundamental human rights. The consequences resulting from rising global temperatures, the intensification of extreme weather events, and environmental degradation directly affect rights such as life, health, food, and access to an ecologically balanced environment, see Arts. 5, 6, and 225 of the Federal Constitution of 1988.
Thus, it is expressly stated in the latter provision of Brazil's Magna Carta that “Everyone has the right to an ecologically balanced environment, which is a good of common use for the people and essential to a healthy quality of life, with the duty imposed upon the Public Power and the community to defend and preserve it for present and future generations” (BRASIL, 1988).
In this sense, the climate crisis imposes the need to reinterpret international climate governance through the lens of human rights protection, recognizing environmental degradation as an impediment to the minimum conditions for a dignified existence. From the perspective of responsibility, state action in addressing climate change must be understood as an expression of legal obligations to protect human rights. Domestically, Law No. 12,187/2009, which establishes the National Policy on Climate Change, sets out guidelines and instruments aimed at mitigating greenhouse gas emissions and adapting to climate impacts, consolidating the state's duty to act.
From this perspective, the aforementioned law reinforces this legal dimension of state responsibility by structuring the National Policy on Climate Change around principles such as prevention and precaution, set forth in Article 3, imposing on the state the duty to act in the face of environmental risks, even amid scientific uncertainty. Furthermore, by establishing as objectives—stated in Article 4—the harmonization of socioeconomic development with the protection of the climate system and the reduction of greenhouse gas emissions, as well as by establishing guidelines for the integration and implementation of public policies aimed at mitigation and adaptation—pursuant to Article 5—the statute dispels any notion of absolute discretion in state action.
Added to this is the provision of concrete implementation instruments, such as the National Plan on Climate Change and the National Climate Change Fund—prescribed in Article 6 of the cited legislation—and the internalization of national emission reduction commitments to achieve the objectives of the PNMC—in view of Article 12—demonstrating that the Brazilian legal system not only authorizes, but demands effective climate action.
According to a study conducted by the International Energy Agency (IEA), updated on October 6, 2023, greenhouse gas emission projections for the year 2030 remain considerably high and above the target established by the NDCs to reduce global warming. In the following figure, it can be observed that there is a considerable, yet insufficient, reduction for the effective resolution of the problem.
Figure 1 – Projections of global CO₂ emissions up to 2023 according to the NDCs
Thus, it must be noted that the insufficiency of the NDCs highlights a critical ambition gap that transcends the technical realm to reach the protective core of human dignity. Omission or inadequacy in implementing these measures—in line with the commitments undertaken in the Paris Agreement—may constitute an indirect violation of fundamental rights, insofar as it contributes to the intensification of foreseeable and preventable environmental damage. Thus, it is undeniable that the ineffectiveness of Nationally Determined Contributions represents not only a failure of international governance, but also a breach of state duties legally established within the domestic legal order.
The systemic degradation of the environment acts as a vector of violations that removes the ecological foundation necessary for the exercise of any civil or social right. In the legal sphere, this connection is inseparable, as Inter-American jurisprudence points out through Advisory Opinion No. 23 of 2017 (OC-23/17): "environmental damage may affect all human rights, in the sense that the full enjoyment of all human rights depends on a propitious environment". Therefore, it is important that the preservation of the climate system be viewed as a primary public interest and a precondition for the survival of humanity.
Furthermore, socio-environmental vulnerability stands out on a disproportionate scale among those who already inhabit the margins of state protection. Social fabrics such as Indigenous peoples, traditional communities, coastal residents, and subsistence farmers increasingly face existential threats to their territories and life plans. The inability of states to ensure a stable climate for these more susceptible groups is evident, reflecting a series of failures in safeguarding human dignity. For such social groups, environmental protection is an indispensable condition for survival, and degradation intensifies harsh realities of exposure and fragility that compromise physical and psychological integrity.
The dimension of gender and poverty further compounds this susceptibility: according to UN Women (2024), 1 in 10 women worldwide lives in extreme poverty, a scenario worsened by climate change, which is projected to push an additional 158 million women and girls into poverty by 2050—placing them among the primary victims of environmental disasters. Frequently, repressive cultural norms and the unequal distribution of resources prevent these vulnerable groups from actively participating in decision-making or accessing protection and resilience mechanisms. The weakness of international discourse and the stagnation of domestic legislation leave marginalized communities at the mercy of increasingly frequent and intense extreme weather events.
Consequently, inertia or inadequacy in implementing these measures can be construed as a breach of a positive legal duty, especially when it contributes to avoidable environmental harm and, consequently, to the indirect violation of fundamental rights.
4. FINAL CONSIDERATIONS
The analysis conducted demonstrates that Nationally Determined Contributions play a central role in international climate governance by structuring, within the framework of the Paris Agreement, a regime based on flexibility and broad state participation. However, the outcomes of the Global Stocktake reveal that this institutional progress has not been sufficient to ensure the effectiveness of climate action, given the voluntary nature of the commitments and the persistent gap between the necessary ambition and the targets adopted by states.
This insufficiency produces direct consequences for human rights, especially for vulnerable populations, by intensifying environmental harm and undermining conditions essential for a dignified existence. Although the cooperative rationale of the Paris Agreement encourages international participation, it also exposes the regime to political fluctuations and institutional setbacks, underscoring its structural fragility.
In this context, the effectiveness of climate governance cannot be examined solely from an environmental perspective; it must incorporate the protection of human rights as a structural element of climate policies. Thus, emissions reduction and the strengthening of international cooperation take on not only an environmental dimension, but also a legal and social one, in light of the climate crisis's disproportionate impacts on vulnerable populations and states' protective responsibilities.
Thus, it is concluded that NDCs represent a significant advancement, but are not sufficient on their own to guarantee either the effectiveness of global climate governance or the adequate protection of human rights in the face of the climate crisis. Their effectiveness will therefore depend on the sustained commitment of states and the strengthening of international cooperation, so as to translate formal participation into concrete results to tackle the climate crisis and protect human dignity.