Nuclear energy and climate change mitigation: the NEA analysis


In a study on the role of nuclear power in mitigating global warming, the Nuclear Energy Agency (NEA) calculates that extending existing reactors and expanding the global fleet could save 87 gigatonnes of CO2 emissions. In addition, a wave of innovations in this sector would make it possible in the near-term and medium-term to replace part of the energy with a high rate of greenhouse gas emissions.

On May 3, the OECD Nuclear Energy Agency (NEA) published a study titled: “Meeting Climate Change Targets: The Role of Nuclear Energy.” It highlights the need to develop the existing nuclear fleet to meet the commitments made in 2015 during the Paris Agreement. In addition to detailing the advantages of using nuclear energy, this work also makes a series of policy recommendations for dealing with climate change.

The authors recall in the preamble that the latest report of the Intergovernmental Panel on Climate Change (IPCC) of the United Nations concludes that today, climate change is widespread, rapid, and intensifying. This calls for strong, fast, and sustained reductions in greenhouse gas emissions. For its part, the International Energy Agency (IEA) has pointed out that deploying all available clean energy technologies will be necessary to stay on track toward a net zero objective.

The electrification of various sectors represents a key element of the global decarbonization strategy. However, even with improvements in demand, side management, and energy efficiency, electricity demand will grow increasingly over the coming decades.

The need to mobilize all low-carbon technologies

Constrained by the global carbon budget, carbon emissions will peak in the next few years and go to zero by 2100 or sooner. To achieve this goal, policy changes worldwide are needed as well as massive investments in innovation, infrastructure and the deployment of non-emitting energy resources.

Faced with this observation, all the recognized models show that nuclear energy is essential in global climate change mitigation efforts. Indeed, investments in life extensions of nuclear power plants, retrofits of existing reactors, and new construction would make achieving the goals of the Paris Agreement cheaper and more feasible.

If countries do not invest in nuclear energy, the risks of not meeting the Paris targets will be much more significant. The IEA estimates that, without nuclear power, it would cost the world around $1.6 trillion more to meet the Paris targets.

The role of nuclear energy in a net zero policy

The world’s active nuclear fleet is currently the second-largest source of non-emitting electricity generation, providing around 10% of the world’s electricity thanks to 444 nuclear power reactors.

In 2018, the IPCC found that, on average, the 1.5°C scenario trajectories require nuclear energy to reach a capacity of 1,160 gigawatts of electricity by 2050, up from 394 gigawatts in 2020.

The NEA study reveals that this could be achieved by combining the long-term operation of existing plants with the large-scale construction of new Generation III nuclear technologies and small modular reactors. This would avoid 87 gigatonnes of cumulative emissions between 2020 and 2050, preserving 20% of the global carbon budget in a 1.5°C scenario.

In addition, a wave of innovations in the nuclear sector would offer new technologies and energy opportunities in the near-term and medium-term to replace part of the energy with a high rate of greenhouse gas emissions.

Challenges and opportunities

While nuclear power may play a much more significant role in global efforts to mitigate climate change, many challenges remain

The estimates presented in the study are not forecasts but represent what could be achieved if decisions are taken quickly to seize this opportunity. Therefore, the question of system costs, project timelines, public confidence, and clean energy financing are subjects that political decision-makers must address. Additionally, a systems approach is needed to understand the total costs of electricity provision and ensure that markets value the desired outcomes.

Governments, therefore, have an essential role to play. This role can range from direct financing to setting a policy framework that allows innovative nuclear projects to compete on an equal footing with other non-emitting energy projects while ensuring effective risk allocation.

Finally, ensuring full representation in policy discussions about clean energy and climate change is crucial. Nuclear power already makes an essential contribution to reducing emissions and must continue growing to meet the Paris Agreement’s goals. On the other hand, nuclear innovations are expected to significantly contribute to emission reduction targets in the near term. Policies should be technology-neutral and structured to encourage desired outcomes such as reduced emissions and security of energy supply.

Experience shows that with the proper policy framework and a robust systemic approach, nuclear energy can quickly become one of the low-carbon energy alternatives. The rapid construction of new nuclear energy is therefore possible. But it requires a vision and a clear plan. In China and South Korea, construction lead times are around 5 to 6 years. Inspired by these countries, nuclear energy could thus play a key role in mitigating climate change.

NEA recommendations


  1. Act now: Governments and industries should work together to deploy nuclear energy innovations.
  2. Understand and reduce costs: The nuclear energy sector should implement the recommendations of the NEA study published in 2020. On the other hand, governments should take a systems-level perspective when developing electricity policies.
  3. Address timelines: Governments and industry should learn from successful examples of rapid deployment of nuclear energy to decarbonize electricity grids. Regulators should work together to harmonize licensing approaches.
  4. Build public confidence: Governments and industry should engage citizens to build public trust, ensuring that public dialogue on energy options is based on evidence, not hoaxes.
  5. Underpin investment: Governments should support a technology-neutral approach and invest more in nuclear energy.
  6. Ensure full representation in policy discussions on clean energy and climate change: Governments should break the silence on nuclear power in policy discussions on clean energy and climate change, raise the profile of energy alongside other non-emitting energy technologies and ensure that nuclear is included in conversations at climate change conferences.

Published on 16 May 2022

By Maximilien Struys

Link to the study :