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Paris Agreement: Assessing the Global Commitment to Carbon Emission Reductions

Introduction

The Paris Agreement, adopted in 2015 under the United Nations Framework Convention on Climate Change (UNFCCC), represents a landmark international treaty aimed at addressing the global challenge of climate change through coordinated efforts in mitigation, adaptation, and financing. Signed by 196 parties at the 21st Conference of the Parties (COP21) in Paris, France, the agreement seeks to limit global temperature rise to well below 2°C above pre-industrial levels, with an aspirational target of 1.5°C. This article assesses the global commitment to carbon emission reductions as enshrined in the Paris Agreement, examining the legal frameworks that enable countries to enter into such treaties, the incorporation of international obligations into national law, and the broader implications of treaty law under the Vienna Convention on the Law of Treaties (VCLT) 1969. While the focus is on the global commitment, specific attention is given to the legal mechanisms by which a hypothetical country can engage with the Paris Agreement, including whether it operates under a monist or dualist system of treaty incorporation. Additionally, the relationship between the Paris Agreement and the VCLT is explored to provide insights for other nations on treaty engagement.

The Paris Agreement and Global Commitment to Carbon Emission Reductions

The Paris Agreement marks a significant shift in international climate policy by establishing a framework that combines binding and voluntary elements. Unlike its predecessor, the Kyoto Protocol, which imposed mandatory emission reduction targets on developed countries, the Paris Agreement introduces Nationally Determined Contributions (NDCs). Under Article 4 of the Paris Agreement, each party is required to prepare, communicate, and maintain successive NDCs that reflect their highest possible ambition in reducing greenhouse gas emissions (United Nations, 2015). The flexibility of NDCs allows countries to tailor their commitments to national circumstances, fostering broader participation, yet it also raises questions about accountability and the sufficiency of global efforts to meet the temperature goals.

As of 2023, 195 members of the UNFCCC are parties to the Paris Agreement, demonstrating near-universal commitment (UNFCCC, 2023). However, the voluntary nature of NDCs has led to disparities in ambition. While some countries, such as the European Union, have pledged aggressive targets—aiming for a 55% reduction in emissions by 2030 compared to 1990 levels—others have submitted less ambitious plans (Consilium, 2025). Recent studies suggest that current NDCs collectively fall short of the reductions needed to limit warming to 2°C, let alone 1.5°C, with a required increase in emission reduction rates by 80% beyond existing commitments (Nature, 2021). This gap highlights the challenge of translating political commitments into actionable, enforceable policies at the national level.

The Paris Agreement also includes mechanisms for transparency and accountability under Article 13, which establishes a framework for reporting and reviewing progress on NDCs. This “pledge and review” system aims to encourage upward revisions of commitments over time, yet its effectiveness depends on domestic implementation and international cooperation (United Nations, 2015). The Global Stocktake, mandated by Article 14, provides a periodic assessment of collective progress, with the first completed in 2023 at COP28, underscoring the need for accelerated action (UNFCCC, 2023). These provisions illustrate the Paris Agreement’s innovative approach to fostering global commitment while revealing the persistent challenges in achieving the depth of emissions reductions required.

Legal Framework for Treaty Engagement: Entering the Paris Agreement

For any country to participate in the Paris Agreement, it must navigate the legal processes governing the entry into international treaties. The Paris Agreement, as an instrument under the UNFCCC, is a legally binding treaty within the framework of international law. The ability of a country to enter into such agreements is typically governed by its national constitution or legal system, which outlines the authority and procedures for treaty-making. Since this article considers a hypothetical country, the analysis will provide a general framework that can be adapted to specific national contexts, focusing on the legal provisions of the Paris Agreement itself as a guide to treaty engagement.

Article 20 of the Paris Agreement specifies the procedures for signature, ratification, acceptance, approval, or accession. It states that the Agreement was open for signature from April 22, 2016, to April 21, 2017, at the United Nations Headquarters in New York, and thereafter open for accession by any state or regional economic integration organization that is a party to the UNFCCC (United Nations, 2015). For a country to become a party, it must express its consent to be bound by the Agreement through one of these methods, typically involving a formal act by the head of state, government, or designated authority, followed by the deposit of the instrument of ratification or accession with the UN Secretary-General, who serves as the depositary under Article 21.

The entry into force of the Paris Agreement, as outlined in Article 21, required ratification by at least 55 parties to the UNFCCC, accounting for at least 55% of total global greenhouse gas emissions. This threshold was achieved on October 5, 2016, with the Agreement entering into force on November 4, 2016 (United Nations, 2015). For individual countries joining after this date, the Agreement enters into force on the thirtieth day after the deposit of their instrument of ratification or accession. This legal structure ensures that countries can engage with the Agreement in a manner consistent with international norms, providing a clear pathway for participation.

In terms of national authority, the process of entering treaties generally involves the executive branch negotiating and signing the treaty, followed by legislative approval if required by domestic law. The Paris Agreement does not prescribe how countries should structure this internal process, leaving it to national legal systems to determine the competent authority. For a hypothetical country, this might involve the president or prime minister signing the Agreement, followed by parliamentary ratification if the constitution mandates such a step. This flexibility accommodates diverse legal traditions while ensuring compliance with the procedural requirements set forth in the Agreement itself.

Monist vs. Dualist Approaches to Treaty Incorporation

The incorporation of international treaties like the Paris Agreement into national law depends on whether a country follows a monist or dualist approach to international law. In a monist system, international law is automatically part of domestic law upon ratification of a treaty, requiring no additional legislative action for its provisions to be enforceable in national courts. In contrast, a dualist system treats international and domestic law as separate, necessitating specific legislation to translate treaty obligations into national law before they can be applied domestically.

For the purposes of this analysis, let us assume the hypothetical country operates under a dualist system, which is common among many common law jurisdictions. In such a system, the executive may ratify the Paris Agreement, but its provisions—such as the commitment to submit and implement NDCs under Article 4—would not be enforceable in domestic courts until parliament enacts enabling legislation. This process ensures that international commitments are aligned with national legal and policy frameworks, but it can delay implementation if legislative approval is slow or contested. For instance, the country might need to pass a climate act that sets statutory targets for emission reductions consistent with its NDC, establishes regulatory mechanisms for monitoring emissions, and allocates resources for adaptation measures as per Article 7 of the Agreement (United Nations, 2015).

In contrast, if the hypothetical country were a monist state, ratification of the Paris Agreement would immediately confer legal effect to its provisions within the domestic legal order, assuming no conflict with the constitution. This could expedite the implementation of climate policies but might raise challenges if national laws or institutional capacities are unprepared to meet international obligations. Regardless of the approach, the Paris Agreement’s emphasis on nationally determined contributions means that domestic legal frameworks play a critical role in operationalizing global commitments, highlighting the interplay between international treaty law and national governance.

The choice between monist and dualist systems also influences how countries address potential conflicts between the Paris Agreement and domestic law. In a dualist system, enabling legislation can be tailored to resolve such conflicts, whereas in a monist system, courts may need to interpret international obligations in light of domestic norms, potentially leading to inconsistent application. For the Paris Agreement, which relies on domestic action to achieve global goals, the effectiveness of treaty incorporation is a determinant of a country’s ability to contribute to carbon emission reductions.

The Paris Agreement and the Vienna Convention on the Law of Treaties 1969

The Vienna Convention on the Law of Treaties (VCLT), adopted in 1969, is a foundational instrument in international law that governs the formation, interpretation, and termination of treaties. It provides a comprehensive framework for how states enter into, perform, and exit treaty obligations, ensuring predictability and uniformity in international relations. A key question is whether the Paris Agreement, as a treaty under the UNFCCC, is a party to the VCLT, and how this informs other countries on engaging with the Agreement.

To clarify, the VCLT applies to treaties between states, and its provisions are binding on states that have ratified it or are otherwise bound by its customary rules. As of now, 116 states are parties to the VCLT, and many of its provisions, such as those on treaty interpretation (Articles 31-33), are considered customary international law, applicable even to non-parties (United Nations, 1969). The Paris Agreement itself is not a “party” to the VCLT, as treaties are not legal entities capable of entering into other treaties; rather, the states that are parties to the Paris Agreement are subject to the VCLT’s rules when engaging with it. The UNFCCC, under which the Paris Agreement was adopted, is also governed by the principles of the VCLT in terms of its formation and operation as a treaty framework.

The VCLT’s relevance to the Paris Agreement lies in its procedural and substantive guidelines. For instance, Article 26 of the VCLT establishes the principle of pacta sunt servanda, meaning treaties must be performed in good faith, which underpins the obligation of Paris Agreement parties to implement their NDCs (United Nations, 1969). Similarly, Article 27 of the VCLT prohibits states from invoking domestic law as a justification for failing to perform treaty obligations, reinforcing the expectation that countries align their national laws with international commitments. For other countries considering engagement with the Paris Agreement, the VCLT provides a legal roadmap: they must follow proper procedures for signature and ratification as outlined in Article 11-16 of the VCLT, ensure their consent to be bound is expressed clearly, and adhere to the Agreement’s terms in good faith.

Moreover, the VCLT’s rules on treaty interpretation are critical for resolving ambiguities in the Paris Agreement, such as the precise nature of “common but differentiated responsibilities” under Article 2.2 (United Nations, 2015). Article 31 of the VCLT mandates that treaties be interpreted in good faith, in accordance with the ordinary meaning of their terms, in context, and in light of their object and purpose (United Nations, 1969). This approach ensures that countries entering the Paris Agreement understand and apply its provisions consistently, fostering mutual trust and cooperation.

For countries not party to the VCLT, many of its principles apply as customary international law, meaning they are still bound by core norms when engaging with the Paris Agreement. This universality enhances the Agreement’s accessibility and provides a stable legal foundation for global participation. However, countries must also consider capacity and resource constraints when translating VCLT-guided treaty obligations into actionable domestic policies, particularly in the context of climate commitments that require significant economic and social transformation.

Challenges and Opportunities in Global Commitment to Emission Reductions

While the Paris Agreement establishes a robust framework for global commitment to carbon emission reductions, several challenges hinder its full realization. First, the voluntary nature of NDCs, while inclusive, allows for significant variation in ambition and effort. Developed countries, which historically bear greater responsibility for emissions, often face domestic political resistance to aggressive targets, as seen in the United States’ fluctuating engagement with the Agreement—withdrawal in 2020, rejoining in 2021, and announced withdrawal again in 2025 (Wikipedia, 2025). Developing countries, on the other hand, grapple with limited financial and technological resources to transition to low-carbon economies, despite the Agreement’s provisions for support under Articles 9-11 (United Nations, 2015).

Second, the lack of enforcement mechanisms within the Paris Agreement poses a risk to compliance. While the transparency framework under Article 13 and the Global Stocktake under Article 14 aim to promote accountability, there are no penalties for failing to meet NDC targets. This reliance on moral and diplomatic pressure may not suffice to drive the urgent action needed, particularly as global emissions continue to rise in key sectors like energy and transportation (UNFCCC, 2023).

Nevertheless, the Paris Agreement offers significant opportunities for advancing carbon emission reductions. The emphasis on progressive enhancement of NDCs every five years encourages a race to the top, as countries are incentivized to strengthen their commitments in response to global progress and peer pressure. The Agreement’s focus on adaptation and resilience under Article 7 also addresses the immediate needs of vulnerable populations, ensuring that emission reductions are pursued alongside efforts to manage climate impacts (United Nations, 2015). Furthermore, international cooperation in finance and technology transfer, as mandated by Articles 9 and 10, can bridge capacity gaps, enabling broader participation in global climate goals.

Lessons for National Implementation and Treaty Engagement

For a hypothetical country engaging with the Paris Agreement, the interplay between international obligations and domestic legal systems is paramount. Whether adopting a monist or dualist approach, the country must ensure that its internal processes facilitate the timely and effective implementation of NDCs. This might involve creating specialized agencies to oversee climate policy, enacting legislation to enforce emission targets, and aligning national budgets with adaptation and mitigation priorities. The experiences of other nations, such as the United Kingdom’s submission of an 81% emission reduction target by 2035 under its NDC, can serve as a model for setting ambitious yet feasible goals (GOV.UK, 2025).

Engagement with the Paris Agreement also requires adherence to the principles of the VCLT, ensuring that treaty-making processes are transparent and legally sound. Countries must build institutional capacity to negotiate, ratify, and implement treaties, learning from the procedural clarity provided by the VCLT and the Paris Agreement’s own ratification mechanisms. This is particularly important for states with limited experience in international climate diplomacy, as procedural missteps could undermine their ability to contribute effectively to global efforts.

Moreover, the Paris Agreement’s structure offers lessons for future treaty design. Its blend of binding procedural obligations (e.g., submitting NDCs) with voluntary substantive commitments (e.g., emission targets) provides a flexible model that can be adapted to other areas of international cooperation. Other countries can draw on this approach to craft treaties that balance sovereignty with collective responsibility, ensuring broad participation without sacrificing ambition.

Conclusion

The Paris Agreement stands as a testament to global resolve in combating climate change, uniting nearly all nations under a shared commitment to carbon emission reductions. Through its innovative mechanisms like NDCs, transparency frameworks, and the Global Stocktake, it seeks to translate political will into tangible action. However, the gap between current commitments and the reductions needed to meet temperature goals underscores the urgency of enhanced ambition and implementation. Legally, the Agreement operates within the broader framework of international treaty law, guided by principles such as those in the VCLT 1969, which inform how countries enter into and fulfill their obligations. For a hypothetical country, whether monist or dualist, the process of engaging with the Paris Agreement involves aligning national legal systems with international commitments, a task that requires both procedural adherence and substantive policy reform. As the world navigates the complexities of climate action, the Paris Agreement offers not only a blueprint for emission reductions but also a model for international cooperation, with lessons that extend beyond climate policy to the broader realm of global governance.

References

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