What Is a Nationally Determined Contribution (NDC) and How Does It Help Tackle Climate Change?

In 2015, under the Paris Agreement, the 196 parties (195 countries plus the European Union, as a regional economic integration organization) agreed that each party would have to set out its plans to curb global warming. Specifically, each party must explain how it will reduce greenhouse gas (GHG) emissions, adapt to the effects of climate change and, in the case of developed countries, contribute to climate finance. According to the United Nations, states must prepare, communicate and maintain successive contributions that they intend to achieve.

Although countries are not legally bound to meet the exact quantified targets in their NDCs, they must submit new NDCs every five years, and each successive contribution must represent a progression beyond the previous one and reflect the highest possible ambition. The secretariat of the United Nations Framework Convention on Climate Change (UNFCCC) records every contribution on this platform.

Xira Ruiz, a professor of International Relations at Complutense University of Madrid who specializes in climate negotiations and environmental issues, explains that “in practice, NDCs are highly flexible in their content, and each country sets out how it will contribute to climate action, both by reducing its greenhouse gas emissions and by including goals such as preserving carbon sinks—and even adaptation targets.”

What emissions reduction commitments does an NDC include?

To turn international climate goals into concrete action, NDCs structure countries’ efforts around three pillars:

• Climate change mitigation. This pillar focuses on cutting greenhouse gas (GHG) emissions. NDCs set quantifiable targets in sectors such as energy, transportation, industry, agriculture and waste. They range from renewable energy to the conservation of forests, which can act as carbon sinks. They distinguish between “unconditional” targets (met with a country’s own resources) and “conditional” targets (subject to external financial support).
• Climate adaptation. This is the process of adjusting natural and human systems to respond to the actual or expected impacts of climate change and to take advantage of potential opportunities. In NDCs, adaptation aims to build resilience to risks such as droughts, floods and heat waves. NDCs may include adaptation goals and measures, which may also be linked to National Adaptation Plans (NAPs). Countries prioritize protecting infrastructure, ecosystems and food production.
• Climate finance. One of the main agreements reached at COP29 was the New Collective Quantified Goal (NCQG), which sets a climate finance target of at least $300 billion a year by 2035, with developed countries taking the lead. This commitment forms part of a broader goal of reaching $1.3 trillion a year in public and private finance for developing countries.

As Xira Ruiz points out, “the EU, for example, aims to cut its net emissions by at least 55% by 2030 (compared with 1990 levels) and to achieve climate neutrality by 2050.” She also stresses that “other countries may use 2000 or 2005 as their base year, since there is flexibility.”

How often are NDCs updated? The Paris Agreement’s ambition cycle

NDCs are reviewed periodically through the so-called “ambition cycle,” a Paris Agreement mechanism designed to ensure that countries step up their climate efforts. The climate negotiations expert argues that this mechanism “does not exist as such; it is a combination of several articles of the Paris Agreement. Through it, states agreed that NDCs would have to become increasingly ambitious.”

Article 4 (paragraphs 9 and 11) of the Paris Agreement requires each country to communicate a new contribution to the UNFCCC secretariat every five years. This five-year cycle requires each NDC to represent a progression and reflect the country’s “highest possible ambition.” A Party may also revise its NDC at any time, but only to strengthen its commitments, not to weaken them.

After the first NDCs were submitted in 2015 and updated in 2020–2021 (with targets for 2030), some countries submitted their third-generation NDCs, with targets for 2035, in 2025. The NDC update cycle takes into account the outcome of the Global Stocktake (GST), an assessment carried out every five years to measure collective progress toward the goals of the Paris Agreement. As the UNFCCC points out, NDCs 3.0—the third generation of national contributions—must take into account the outcome of the first Global Stocktake, completed in 2023, and reflect greater ambition than previous rounds.

According to the UNFCCC, the Global Stocktake is “like an inventory.” “By assessing where the world stands in meeting the goals of the Paris Agreement and drawing on its inputs, the stocktake can help policymakers and stakeholders strengthen their climate policies and commitments in their next round of NDCs, paving the way for accelerated action,” the organization says.

How do we know whether an NDC is enough?

To determine whether climate plans are adequate, the UNFCCC and UNEP (the United Nations Environment Programme) compare the combined impact of all NDCs with the Paris Agreement goal: holding the increase in the global average temperature to well below 2°C and pursuing efforts to limit it to 1.5°C above pre-industrial levels. This is the warming threshold that the scientific community and world leaders identified as the critical limit for avoiding the most severe and irreversible consequences of climate change.

Expert assessments show real but still insufficient progress, as highlighted in an analysis by BBVA Research:

• What is being done: under current policies, the planet is on track for around 2.8°C of warming by the end of the century (compared with the 3.7°C projected in 2015).
• What has been pledged: if countries fully met every commitment set out in their NDCs, warming would be limited to between 2.3°C and 2.5°C.
• What science requires: to ensure a livable planet, science underscores the need to limit warming to 1.5°C in order to reduce the most severe risks and impacts of climate change.

According to the International Relations professor, “it is very difficult to assess NDCs precisely because they are so flexible that many of them cannot easily be compared.” This is because they use different base years and different targets, and some include varying degrees of conditionality. Even so, Ruiz notes that organizations such as Climate Action Tracker assess whether individual NDCs are in line with what would be expected of a country, given its historical GHG emissions or economic capacity.

Why will NDCs be on the agenda at COP31?

COP31 in Antalya, Türkiye, will put the practical implementation of NDCs at the heart of the debate. The central priority of the dual presidency (Türkiye and Australia) is to move from announcements to credible delivery. Julián Cubero, lead economist for the Climate Change Economics Cluster at BBVA Research, notes that “COP31 should mark the shift from commitments to delivery. The challenge is not to add new initiatives, but to ensure that targets are backed by concrete measures, financing and mechanisms for assessing their results.”

According to Ruiz, at COP31 “the Turkish presidency wants to focus on implementing NDCs and on how to close the gap between the commitments made and actual results.” To that end, it has launched the Climate Implementation Bridge, an initiative to help countries secure the financing they need to deliver on their targets.

What if current NDCs aren’t enough to curb climate change?

If NDCs fail to raise ambition or close the implementation gap, temperatures could easily exceed safe limits. That would intensify the impacts on ecosystems, food security and economies. As mitigation requirements tighten, countries face transition costs. BBVA Research’s analysis indicates that measures such as higher fossil fuel prices or carbon taxes can slow growth in the short term, though only temporarily. However, a European Central Bank (ECB) study by Broeders and Mongelli warns that delaying climate action does not avoid these costs; instead, it increases physical and transition risks and may force a sharper adjustment later on.

To ensure that initiatives have a real impact, BBVA Research proposes assessing them with an “Implementation-grade Scorecard” based on five criteria that targets must meet:

1. Measurable: quantified targets with defined timelines.
2. Actionable: specific instruments and projects, with responsible institutions assigned.
3. Funded: specific funding sources and paths to bankability.
4. Accountable: public indicators built into transparency reporting.
5. Climate-consistent: ensuring that progress toward a cleaner economy displaces fossil fuels.

Frequently asked questions about NDCs

Are NDC climate commitments binding?

Countries that are parties to the Paris Agreement are required to prepare, communicate and maintain their nationally determined contributions (NDCs), but not to meet all of their quantified targets exactly. Each new contribution must represent a progression beyond the previous one and reflect the highest possible ambition.

What is the difference between a conditional and an unconditional NDC?

An NDC can include unconditional targets, which the country expects to meet with its own resources, and conditional targets, whose implementation depends on receiving external support, particularly financing. This distinction makes it possible to identify which climate measures require international cooperation.

What are NDCs 3.0, and what targets do they include?

NDCs 3.0 are the third generation of national climate contributions under the Paris Agreement. They set targets for 2035 and must take into account the outcome of the first Global Stocktake, completed in 2023, in order to raise climate ambition.

How are NDCs linked to the Paris Agreement’s Global Stocktake?

Every five years, the Global Stocktake assesses collective progress toward the goals of the Paris Agreement. Its findings serve as a benchmark for countries to revise their NDCs, identify gaps between commitments and results, and strengthen their climate action.

Why is it difficult to compare NDCs across countries?

NDCs do not follow a fully standardized format. Countries may use different base years, set different emissions reduction targets and include commitments that depend on external financing. These differences make it hard to compare their ambition and results directly.

How can you tell whether an NDC is being met?

Under the assessment approach proposed by BBVA Research, climate commitments must have measurable targets, implementation instruments, identified financing, public tracking indicators and consistency with the transition to an economy less dependent on fossil fuels.