The Paris Agreement: A Landmark in Global Climate Change Policy

On 12 December 2015, something unprecedented happened in the world of climate diplomacy. Representatives from 196 countries came together in Paris and agreed on a single, unified framework to fight climate change. The Paris Agreement, as it came to be known, was not just another environmental treaty – it was a turning point in how the world collectively approaches the climate crisis. But what exactly does it say? How does it work? And what are the challenges that threaten to undermine its goals? Let’s break it down.

Core objectives and principles of the Paris Agreement 🔗

At its heart, the Paris Agreement has one overarching mission: to prevent catastrophic climate change by keeping global temperature rise in check. Specifically, the agreement aims to hold the increase in global average temperature to well below 2°C above pre-industrial levels, while pursuing efforts to limit the increase to 1.5°C. That 0.5°C difference between the two targets might seem small, but scientists at the Intergovernmental Panel on Climate Change (IPCC) have shown that it represents a significant reduction in risks – from extreme heatwaves and rising sea levels to biodiversity loss and food insecurity.

Beyond temperature targets, the agreement has two other long-term goals. First, it seeks to increase the global capacity to adapt to climate impacts and build climate resilience, especially in ways that do not threaten food production. Second, it aims to make financial flows consistent with a pathway toward low greenhouse gas emissions and climate-resilient development. In other words, money needs to start flowing toward clean energy and away from fossil fuels.

The principle of common but differentiated responsibilities 🔗

One of the agreement’s foundational principles is equity. Not all countries have contributed equally to the climate crisis, and not all countries have the same capacity to respond. The Paris Agreement is guided by the principle of “common but differentiated responsibilities and respective capabilities” – a concept rooted in the original 1992 UN Framework Convention on Climate Change (UNFCCC). This means that while every country must act, developed nations – which have historically emitted the most greenhouse gases – bear a greater responsibility to lead the way and to support developing nations financially and technologically.

Transparency as a pillar 🔗

The Paris Agreement also established, for the first time under a UN climate treaty, a unified transparency framework that applies to all countries. Each party is required to regularly report on its emissions and its progress toward meeting its climate targets. This system of mutual accountability was a major breakthrough, as the earlier Kyoto Protocol’s compliance mechanisms were seen by some countries as too intrusive, which discouraged broader participation. The Paris model opted for a less punitive but more inclusive approach – every country reports, every country is reviewed, and the information is publicly accessible.

Nationally Determined Contributions (NDCs) 🔗

Perhaps the most innovative feature of the Paris Agreement is the concept of Nationally Determined Contributions, or NDCs. Unlike the Kyoto Protocol, which imposed top-down emissions targets on developed nations, the Paris Agreement uses a bottom-up approach. Each country is free to define its own climate targets and strategies based on its national circumstances, capabilities, and development priorities.

How NDCs work 🔗

Every party to the agreement is required to prepare, communicate, and maintain an NDC. These contributions outline the specific actions a country will take to reduce greenhouse gas emissions and build resilience to climate impacts. The agreement does not prescribe the exact form these contributions must take – at a minimum they should cover mitigation, but they can also include pledges on adaptation, finance, technology transfer, and capacity building.

What makes the NDC system dynamic is the built-in five-year review cycle. Every five years, countries are expected to submit updated NDCs that reflect their “highest possible ambition.” This ratcheting mechanism is designed to ensure that global climate action progressively intensifies over time, since the initial pledges submitted by countries were widely acknowledged to be insufficient to meet the 2°C goal, let alone 1.5°C.

The global stocktake 🔗

To assess collective progress, the agreement introduced the Global Stocktake – a comprehensive evaluation conducted every five years. The first Global Stocktake concluded at COP28 in Dubai in 2023, where parties agreed on a decision to accelerate action across mitigation, adaptation, and finance by 2030. That decision included a historic call on governments to speed up the transition away from fossil fuels toward renewable energy sources like wind and solar in their next round of NDCs. This was the first time a COP decision explicitly addressed fossil fuels in this way.

The Global Stocktake is crucial because it provides a reality check. It reveals the gap between what countries have pledged and what the science says is needed, creating political pressure to do more.

Commitment to human rights and climate justice 🔗

The Paris Agreement broke new ground by becoming the first multilateral climate treaty to reference human rights. Its preamble states that parties should, when taking action to address climate change, respect, promote, and consider their obligations regarding human rights, the right to health, the rights of indigenous peoples, local communities, migrants, children, persons with disabilities, and people in vulnerable situations. It also emphasises gender equality, the empowerment of women, and intergenerational equity.

Why human rights matter in climate policy 🔗

Climate change is not just an environmental issue – it’s a human rights issue. Rising seas threaten the very existence of small island developing states. Droughts and floods destroy livelihoods and displace millions. Air pollution from fossil fuel combustion kills millions each year. The people who suffer most are those who have contributed the least to the problem: marginalised communities, indigenous peoples, and populations in the Global South. By acknowledging human rights in its text, the Paris Agreement sends a clear signal that climate action must protect – not harm – the most vulnerable.

Climate justice: more than a concept 🔗

The preamble also notes the importance of “climate justice” – a concept that recognises how the burdens of climate change fall disproportionately on those least responsible for causing it. According to UNEP, climate justice is not an add-on but a foundational principle of the agreement. However, a significant criticism is that human rights and climate justice language was placed in the preamble rather than in the operative articles of the treaty. This means it carries interpretive weight but does not create directly enforceable obligations. Civil society groups and legal scholars continue to push for stronger integration of human rights into climate action under the agreement’s operational framework.

The agreement also introduced provisions on loss and damage – a recognition that some climate impacts are beyond what adaptation can handle. This was a major win for the Alliance of Small Island States and Least Developed Countries. While the agreement calls for “averting, minimising, and addressing” loss and damage, it explicitly states that this cannot be used as a basis for liability or compensation – a concession that was necessary to bring major emitting nations on board.

Climate finance and support for developing nations 🔗

Money is at the centre of the Paris Agreement’s success or failure. Developed countries committed to mobilising $100 billion per year from 2020 to 2025 from both public and private sources to help developing countries reduce emissions and adapt to climate impacts. This funding is meant to cover mitigation projects, adaptation measures, and the transfer of clean energy technologies.

The agreement further encourages developing countries that are in a position to do so to voluntarily contribute to climate finance. At COP29 in Baku in 2024, parties agreed to scale up the collective finance goal beyond the $100 billion target, reflecting the reality that the costs of climate action and adaptation are much higher than originally estimated.

Global compliance and challenges 🔗

The Paris Agreement is legally binding, but – and this is a critical distinction – not all of its provisions carry mandatory force. Countries are legally required to prepare and communicate their NDCs, but they are not legally required to achieve the specific targets they set. There is no penalty mechanism for failing to meet pledges. The agreement relies instead on transparency, public reporting, and the ratchet mechanism to generate peer pressure and political accountability.

The enforcement gap 🔗

This design was intentional. The Kyoto Protocol’s stricter compliance mechanisms were partly blamed for discouraging participation by major emitters. The Paris Agreement sacrificed enforceability for universality – nearly every country in the world signed on. But the trade-off is real. A 2020 assessment by the UN Environment Programme (UNEP) found that under current NDC commitments, global temperatures would likely rise by more than 3°C by the end of the century – well above the agreement’s targets. Even with newer net-zero pledges, there remains a significant gap between ambition and action.

The U.S. withdrawal – twice 🔗

No challenge has tested the Paris Agreement’s resilience quite like the United States’ repeated withdrawal. The U.S. is the world’s second-largest greenhouse gas emitter after China. In June 2017, President Trump announced his intention to pull the country out of the agreement, and the withdrawal took effect in November 2020. President Biden rejoined the agreement on his first day in office in January 2021, and the U.S. formally re-entered on 19 February 2021.

Then, in January 2025, President Trump signed another executive order to withdraw the U.S. from the Paris Agreement for a second time. The withdrawal became effective on 27 January 2026. Additionally, in early January 2026, the U.S. declared its intent to withdraw from the UNFCCC itself, the IPCC, and the Green Climate Fund – an even more dramatic break from the international climate architecture.

This second withdrawal has raised serious concerns. Some researchers worry that U.S. departure could undermine global climate cooperation and encourage other nations to soften their own commitments. Others point out that as of early 2025, no other country had followed the U.S. in withdrawing, suggesting the agreement’s architecture remains robust despite the setback. The UN Climate Chief stated that 194 countries reaffirmed their commitment to the Paris Agreement at COP30, declaring the global transition “irreversible.”

Broader compliance challenges 🔗

The U.S. situation is the most high-profile case, but the Paris Agreement faces broader compliance challenges. Many countries’ NDCs still fall short of what’s needed. A November 2024 UNFCCC synthesis report found a stagnation in aggregate NDC ambition levels. There is also a significant gap between what countries pledge in their NDCs and what they actually implement. Developing nations often lack the financial resources and technical capacity to follow through on their commitments, especially when promised international climate finance arrives late or falls short.

The question of free-riding also looms large. Without enforcement mechanisms, there is always the temptation for countries – especially those under economic pressure – to set weak targets or to quietly fall behind on their pledges. The agreement’s reliance on transparency and peer review is powerful but has limits in a world where geopolitical tensions often override climate cooperation.

Where do we stand today? 🔗

Despite its challenges, the Paris Agreement remains the most important international framework for climate action. It brought nearly every nation on Earth into a common structure for addressing climate change. It created the NDC system, the Global Stocktake, and a transparency framework that did not exist before. It acknowledged loss and damage, included human rights language in a climate treaty for the first time, and set in motion a long-term vision for a net-zero world.

But the gap between ambition and reality is wide. Current policies put the world on track for roughly 2.8°C of warming by the end of the century, according to UNEP’s 2025 Emissions Gap Report. The agreement’s success depends not just on the text itself, but on whether countries – and their citizens, businesses, and institutions – translate pledges into meaningful action on the ground.

What do you think? Can a voluntary, bottom-up framework like the Paris Agreement drive the rapid emissions cuts scientists say are needed – or does the lack of binding enforcement make it fundamentally inadequate? And with the world’s second-largest emitter stepping away from the table, what does that mean for the nations most vulnerable to climate change?

References

1. https://www.un.org/en/climatechange/paris-agreement
2. https://www.ipcc.ch/
3. https://unfccc.int/process-and-meetings/the-paris-agreement
4. https://www.britannica.com/topic/Paris-Agreement-2015
5. https://www.consilium.europa.eu/en/policies/paris-agreement-climate/
6. https://www.mrfcj.org/our-work/areas-of-work/human-rights-and-climate-change/
7. https://www.unep.org/news-and-stories/speech/judiciary-climate-justice-and-environmental-rule-law
8. https://climaterights.org/our-work/unfccc/
9. https://www.diplomatie.gouv.fr/en/french-foreign-policy/climate-and-environment/the-fight-against-climate-change/2015-paris-climate-conference-cop21/cop21-the-paris-agreement-in-four-key-points/
10. https://www.unep.org/
11. https://www.amnesty.org/en/latest/news/2026/01/global-us-withdrawal-from-landmark-paris-climate-agreement-threatens-a-race-to-the-bottom/
12. https://www.sciencedirect.com/science/article/pii/S0301479725027094
13. https://unfccc.int/news/step-back-from-climate-cooperation-will-hurt-us-economy-statement-from-un-climate-chief-on-us