Every five years, all 195 signatories of the 2015 Paris Agreement must submit updated plans to reduce their greenhouse gas emissions to limit global warming. These plans, known as Nationally Determined Contributions (NDCs), are key components of the agreement and represent countries’ highest ambitions for emissions reductions over the next decade.
“The NDC is a pledge,” Director of International Government Relations at Woodwell Climate Dr. Matti Goldberg says. “It’s a pledge by a government to reduce their emissions by a certain amount, by a certain time frame. It can also be a pledge of taking certain types of actions. Each NDC also contains plans and measures to put it into action.”
This year, countries must submit their third NDC ahead of COP30 in Belém, Brazil.
How do NDCs fit into the Paris Agreement?
The Paris Agreement is a legally-binding international treaty under the UNFCCC. The treaty states that signatories should work together to limit global temperature increase to “well under 2°C” above pre-industrial levels and pursue efforts to keep the increase below 1.5°C. Nationally Determined Contributions outline how countries plan to achieve this goal and take other measures as part of the global climate effort.
Each NDC must build upon a country’s previous submission and reflect the party’s “highest possible ambition,” according to the Paris Agreement. While parties are legally required to submit an NDC and pursue actions to reach the target, they are “not legally bound to reach the target,” Goldberg says. “It’s a gigantic loophole in a way…although such flexibility is obviously necessary for countries to agree to this, and it does create a structure of pressure.”
After NDCs are submitted, the UNFCCC assesses the combined impact of countries’ NDCs on projected global emissions in a synthesis report. Parties in the Paris agreement also submit a Biennial Transparency Report (BTR) every two years, which outlines each country’s progress made towards accomplishing their NDCs.
“It’s the country’s own assessment,” Goldberg says. “But if a country announces a metric, then others can, of course, also look at whether that metric is being followed. This information creates the basis for civil society and other governments to put pressure on those governments.” Further transparency is created by a process where international experts review each country’s biennial reports.
Despite the ambitious intent of NDCs, Executive Secretary of the United Nations Framework Convention on Climate Change (UNFCCC) Simon Stiell determined last November that previous pledges fell “miles short of what’s needed to stop global heating from crippling every economy and wrecking billions of lives and livelihoods across every country.”
What is in the 2025 NDCs?
NDCs were initially due in February 2025, but with only 13 Parties submitting on time, the UNFCCC Secretariat announced a cut-off date in September to have enough time to prepare its synthesis before the start of COP30 in November. China, the United States, India, the European Union, Russia and Brazil were the world’s top emitters in 2023. Together, these six parties accounted for 62.7% of all global emissions. Of the top greenhouse gas emitters, only the U.S. and Brazil sent in their NDCs as of early September 2025.
The United States submitted its NDC in 2024 under the Biden Administration and set a target of reducing its net greenhouse gas emissions by 61 to 66% below 2005 levels in 2035. After taking office, President Trump issued an executive order announcing the U.S.’s intent to withdraw from the Paris Agreement, which will go into effect in 2026. After January 2026, the U.S. will no longer be required to submit new NDCs or Biennial Transparency Reports.
Despite the country’s withdrawal, Goldberg says the U.S. may see a reduction in greenhouse gas emissions because of its continuing transition from coal to natural gas, renewables and nuclear power — which, according to Goldberg, is driven more by economics and less by policy. Still, Dr. Christopher Schwalm, Vice President of Science at Woodwell Climate, predicts there is “no way” the United States will hit the targets set out in the NDC given the current global political climate. Even if the U.S. does reach its goals, the NDC still does not align with the global 1.5°C limit, according to the Climate Action Tracker. Schwalm calls the 1.5°C target “dead as a doornail.” To reach this goal, we would have needed global greenhouse gas emissions to peak by 2025.
Brazil’s most recent NDC states a goal of reducing greenhouse gas emissions 59% to 67% compared to its 2005 emissions. Goldberg calls it a “pretty ambitious” absolute target for a country classified as a developing country under the UNFCCC. However, the Brazilian climate organization Observatório do Clima states the NDC goals do not align with the global 1.5°C limit.
How could reaching targets in NDCs impact warming trajectories?
Woodwell Climate research scientist Dr. Abigail Lute wanted to see how much of a difference just two of the top-emitting countries’ NDCs could make.
“Are we moving the needle here or not?” she says. “How much are we moving the needle? Are we moving it enough to avoid 2°C? That’s the big picture, to see how ambitious these new pledges are.”
Lute modeled how both the U.S. and Brazil’s promises together could change the global warming trajectory using a “middle-of-the-road” scenario for future greenhouse gas emissions — though, at the moment, that scenario might be more optimistic than our current trajectory, she says.
For the first ten to 20 years after implementing the NDCs, temperatures will temporarily increase. This is due to the reduction in polluting gases such as sulfates that actually have a cooling effect in the atmosphere. After about a decade or two, the reduction in warming gases such as methane and carbon dioxide will cause temperatures to fall.
According to Lute’s calculations, under moderate emissions scenarios, the probability of exceeding 2°C is 25% by 2050 and 78% by 2100. If both the U.S. and Brazil reach their NDC targets, the probability of exceeding 2°C stays about the same for 2050 but drops down to 73% for 2100.
Global warming is expected to reach 1.8°C by 2050 and 2.3°C by 2100 under the medium emissions scenario. With the U.S. and Brazil’s combined NDCs, Lute expects warming to be reduced by about 0.01°C in 2050 and 0.06°C by 2100.
While these contributions may seem small, Brazil and the U.S. only represent two of the 195 parties in the Paris Agreement.
“It’s two of the larger ones for sure, but it’s only two,” Lute says. “If we extrapolate it to everybody, then it can make a meaningful difference…the story here is that everybody needs to contribute. This is a collective problem, and even one large country can’t solve it.”
Last month in Dakar, Senegal, Woodwell Climate Associate Scientist Glenn Bush and Forests & Climate Change Coordinator Joseph Zambo facilitated a high-level workshop with the Democratic Republic of Congo’s Director of Climate Change, Aimé Mbuyi, lead scientist on the country’s Nationally Determined Contributions (NDC) reporting process, Prof. Onesphore Mutshaili, and project consultant Melaine Kermarc. The goal of the workshop was to begin generating a clear set of priorities for the next 5 years for stepping up the ambition of the country’s NDCs, and to discuss strategies for monitoring and reporting on emissions.
Under the Paris Agreement, each country is required to submit to the UN Framework Convention on Climate Change a detailed description of their emissions reduction commitments and then regular reports on progress. Currently, DRC has pledged to reduce emissions by 21% by 2030, focusing on reform in their energy, agriculture, forestry, and other land use sectors. While NDCs are intended to represent a country’s highest possible ambition, DRC is looking to step up further. Officials are at work developing a plan to reach net-zero emissions, which would place the country among the leaders of climate policy in Africa.
In order to do this, DRC needs a reliable framework for measuring and monitoring emissions, so that progress can be accurately reported on. At the workshop, Bush, Mbuyi, Zambo, Kermarc and Mutshaili discussed ways to strengthen the NDC reporting process. Among the top needs identified was stronger institutional scientific capacity, increased coordination and data sharing, and more funding and awareness of the process at local and provincial levels.
“High quality data is essential to building a high integrity NDC,” says Bush. “Improving the scope and quality of data available to monitor carbon will not only help the country meet the highest tier of reporting standards, but also access performance-based payment mechanisms to help finance the transition to a low emissions economy.”
Through their conversations about challenges and opportunities, the group identified three areas for intervention that will help the country navigate towards a stronger emissions reduction plan. These recommendations were outlined in a report on the workshop proceedings.
- Improved governance and policy management: Establishing a National Climate Change Council to better integrate climate policy into national development plans.
- Science-backed carbon accounting and budgeting: Developing credible data standards for measuring emissions and ecosystem services to support transparent and effective reporting on climate performance.
- Cross-sectoral integration: Promoting emissions reductions across all sectors through collaborative partnerships, particularly in the field of climate-smart agriculture and carbon payment mechanisms.
Mr Aimé Mbuyi, Head of the Climate Change Division (CCD) at the DRC’s Ministry of the Environment and Sustainable Development, declared that “these recommendations reflect an important set of practical steps to move from aspiration to operational reality in order to increase the financing and impact to conserve our forests and stimulate sustainable development in the DRC”.
Woodwell Climate Research Center has been a long time partner of the Ministry of Environment and Sustainable Development. The Center is assisting the ministry in laying the technical foundations to support the NDC improvement process and helping build in-country scientific capacity to make a net-zero emissions plan a reality. This and other partnerships will be essential in transitioning the DRC to a low-carbon economy.
“We appreciated the long-standing trust that has developed over years of formal and informal collaboration on climate policy,” said Mbuyi. “The scientific partnership with Woodwell is invaluable to us at CCD, providing actionable information that has proven essential to advancing the climate mitigation and adaptation agenda.”
