© Image by Billy Joachim from UnSplash
Introduction
“This round of NDCs [Nationally Determined Contributions] is a make or break for […] safeguarding the future for people and our planet.” As stated by the United Nations, this year marks a crucial point in global climate action as countries prepare to submit their third NDCs for ambitions until 2035. NDCs are documents submitted by all parties to the Paris Agreement, which reflect countries’ national efforts to reduce GHG emissions and adapt to climate impacts.
The Paris Agreement sets the goal of keeping the global average temperature “well below 2°C” while striving to limit it to 1.5°C (Article 2). This is to be achieved through countries’ NDCs, which must represent a progression and reflect their “highest possible ambition” (Article 4(3)).
To meet these targets, Carbon Dioxide Removal (CDR) may play a supporting role. As the Intergovernmental Panel on Climate Change (IPCC) explains, CDRs are “technologies, practices, and approaches that remove and durably store carbon dioxide (CO2) from the atmosphere.” While CDR cannot replace ambitious emission reductions, it is part of every scenario of assessments of the IPCC for limiting temperature rise to 2°C or lower by 2100. CDR can be employed on land (e.g., afforestation, enhanced rock weathering) or in the ocean (e.g., Blue Carbon Management, ocean alkalinity enhancement, ocean fertilization).
Article 4(1) of the Paris Agreement aims “to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases.” There is general agreement among scholars that this definition – particularly when compared to other treaty translations – encompasses CDR. Yet, how exactly this inclusion is to be interpreted and implemented is unclear.
Here an issue arises: if mitigation encompasses CDR and if the Paris Agreement requires progressively ambitious NDCs, will countries now increasingly rely on CDR to demonstrate progress? Drawing on the first 2025 NDC submissions and other recent developments, this blog post explores answers to a key question: Should countries be allowed to include CDR in their NDCs under the Paris Agreement? While some actors and scholars view CDR as essential for offsetting hard-to-abate emissions and achieving net-zero targets, others warn it could delay urgent emissions reductions. The state practice on this is thin, as explored in the following.
Status Quo: Third Round of NDCs
CDR was not explicitly mentioned in the first two NDC rounds. However, this time around, it is starting to show up. So far (as at end of April 2025), 20 states have submitted their 2025 NDCs, as per the list below (in order of submissions made, starting from the most recent).
| Countries’ Submissions for the Third Round of NDCs (2025-2035), with those referencing CDR in italics |
| 1. Kenya 2. Zambia (provisional) 3. Cuba 4. Maldives 5. Montenegro 6. Japan 7. Canada 8. Saint Lucia 9. Zimbabwe 10. Marshall Islands 11. Singapore 12. Ecuador 13. Andorra 14. New Zealand 15. United Kingdom (UK) 16. Switzerland 17. Uruguay 18. United States of America (US) 19. Brazil 20. United Arab Emirates (UAE) |
Let’s take a closer look. Canada outlines that it wants to explore CDR options to reach their net-zero targets. However, it also acknowledges the risk of CDR to undermine other emission reductions and has, therefore, set in place a Carbon Management Strategy. Japan plans to achieve GHG reduction partly through decarbonization technologies. Zimbabwe states that forest restoration will be key to their GHG removal. The Marshall Islands plan to “accelerate zero- and low-emission technologies” while particularly mentioning removal technologies like Carbon Capture and Storage (CCS). The UK declares to include “engineered” GHG removals in the future. The US announced it would “take advantage of carbon capture technologies.” The UAE dedicates a large part of their NDCs to negative emissions, outlining plans to use both nature-based solutions, including mangrove afforestation or protecting and restoring seagrass meadows, as well as engineering-based methods for CO2 removal. The latter includes plans for microalgae cultivation, CCS, geological storage, and direct air capture for CO₂ injection into saline aquifers for permanent storage.
By contrast, Montenegro, Zambia, and the Maldives do not spend a single word on CDR-related methods. They simply state that emissions and removals will be estimated using the 2006 IPCC Guidelines without specifying the types of removals included. Only St Lucia refers to carbon removals from forests and the US from soil carbon, without mentioning actual CDR measures.
Among the third-round NDCs that have been analyzed, Canada and the UAE – both high-emitting countries – devote by far the most attention to CDR. Notably, Canada is the only country to explicitly use the term “CDR” and acknowledge its risks, while others rely on vague wording. As these are the first 2025 submissions, other countries may follow their lead on (not) addressing CDR in future NDCs.
To conclude, the Paris Agreement’s implicit reference to CDR offers no guidance on how, or which, CDR technologies should be deployed, instead it raises unresolved question about legal and practical implications. However, evolving state practice may prove decisive in shaping how CDR is incorporated into future NDCs under the Paris Agreement.
Arguments in Favor of Allowing Negative Emissions in NDCs
In light of states already including CDR in their NDCs, there are several policy arguments in favor of it.
- Allowing CDR in NDCs can assist in reaching compliance with the Paris Agreement’s temperature goal.
- It can help countries to compensate for hard-to-abate sectors (like industries, shipping, aviation, or agriculture) and reach net-zero targets many countries have set in a more flexible manner. An inclusion also aligns with the 2023 IPCC Synthesis report, which states that deployment of CDR is “unavoidable” to counterbalance hard-to-abate emissions in order to reach net-zero emissions.
- It can drive investments and innovation in CDR technologies, which can help to scale up technologies that need financial support. In the long-term, this can make CDR technologies accessible to all countries.
- Low-cost CDR measures like reforestation, soil carbon projects, or coastal blue carbon management can benefit developing countries economically. They offer a way to meet NDC commitments while supporting economic growth, enhancing biodiversity and ecosystem functions, and improving local livelihoods.
Arguments Against Allowing Negative Emissions in NDCs
- A moral hazard exists. Countries might over-rely on future CDR promises instead of cutting emissions now, undermining their highest possible ambition. Since most countries have other mitigation options, prioritizing CDR too soon fails to reflect genuine effort.
- Uncertainties arise about how to monitor, report, and verify long-term CO₂ storage, such as in forests or soils. It is hard to quantify, and there is a risk of reversal, such as carbon release from wildfires in afforestation projects.
- It could undermine the principle of Common but Differentiated Responsibilities (CBDR), which requires industrialized nations to lead in mitigation (Article 2(2)). High-cost CDR technologies may favor wealthier countries, leaving developing nations with stricter emissions cuts. However, under the CBDR principle, developed countries must support developing nations through technology transfer, capacity building, and climate financing. CDR could be a way for wealthier states to take responsibility for their historical emissions.
- Legal and regulatory gaps still exist. Clear international standards on how CDR should be accounted for in NDCs are missing. There also is a risk of double counting in carbon markets, which can occur if one country claims removal while another claims credit for funding it.
Recent Developments
Recent legal developments like the advisory opinion at the International Tribunal for the Law of the Sea (ITLOS) and a pending opinion at the International Court of Justice (ICJ) grapple with making states’ open-textured climate change obligations concrete. In its advisory opinion, ITLOS acknowledged the dual potential of ocean-based CDR as both a protective and polluting force (para. 231) but did not clarify its legal status. However, the ICJ may address whether relying on CDR aligns with international law, especially if such reliance delays mitigation. Several states have raised concerns about geoengineering (which includes CDR): Vanuatu argues it violates international obligations, Mauritius highlights environmental risks and urges precaution, and Kiribati warns of potential human rights impacts, asking if delayed mitigation caused by negative emissions could undermine rights to life, health, and a stable climate – a point the ICJ may yet address. Overall, the inclusion of CDR in NDCs remains very ambiguous, and the international advisory proceedings have not added much guidance to the issue thus far.
Possible Solutions
Legal and policy standards are essential to prevent the misuse of CDR in NDCs. One possible solution could be to set fixed state-specific limits, capping CDR use at a certain percentage of a country’s NDC, while also taking into account historical emissions and capabilities. Those limits could even be time-bound, i.e. attributing a smaller extent to CDR inclusion now and a higher extent in the future. Another option could be to discount CDR contributions—counting them at half their value. For instance, if Canada uses CDRs for 10% of its emission reductions, only 5% would count toward its NDC. No matter what specific percentage would be chosen, separating CDR from other emission reductions could prevent overreliance on CDR. Quantitative limits could also reduce greenwashing risks and incentivize genuine mitigation. They could promote fairness by supporting technology transfer to developing countries, in line with the CBDR principle, as investments in CDR innovation would be continued. If applied, transparency remains key, demanding rigorous reporting for continued accountability.
Not only the extent of CDR inclusion matters for effective climate change mitigation, but also the type of CDR technologies. It is important to distinguish between different technologies since CDR methods vary in, e.g., storage permanence, cost, co-benefits, and risks. I argue that only those with clear co-benefits and minimal trade-offs should be eligible for NDC inclusion. Importantly, those CDRs should not only favor the Sustainable Development Goal (SDG) 13 “Climate Action” but also support – or at least not undermine – other SDGs. A regularly updated portfolio of “NDC-eligible” CDR options based on each technology’s maturity and readiness could be established to guide states about which CDRs they could use.
Conclusion
As reflected in the IPCC assessments and early submissions in the third NDC round, CDR is coming–there seems to be no way around it. But if we put the right rules in place, it can complement–rather than compromise–ambitious emission reductions in NDCs in the future. The key is to keep it fair, transparent, and aligned with the goals we have already agreed on.
Josefa Beyer is an LL.M. candidate in Public International Law at Utrecht University, specializing in Environmental Law and the Law of the Sea. She previously worked at the WMU-Sasakawa Global Ocean Institute and holds a B.Sc. in Environmental Sciences.