The myth
Anti-nuclear organisations claim that nuclear energy "emits 5 to 10 times more CO2 than wind and solar." They base this on the work of Storm van Leeuwen & Smith, who arrive at 78-190 grams of CO2 per kilowatt-hour. Based on these figures, they conclude that nuclear energy is not an effective tool against climate change.
The facts
Storm van Leeuwen is not science
The source underpinning this claim — Storm van Leeuwen & Smith's "Nuclear Power: the Energy Balance" — is:
- Never peer-reviewed. The report was published exclusively on the authors' own website.
- Refuted by multiple institutions: Sweden's Vattenfall (based on audited operational data), the Paul Scherrer Institute, the University of Melbourne, and the World Nuclear Association have all demonstrated fundamental errors.
- Overestimates the energy required for uranium mining by a factor of 60+, as demonstrated by verification against actual data from the Rossing mine in Namibia.
Citing Storm van Leeuwen as a scientific source is comparable to citing climate-sceptic blogs to refute the IPCC.
What the science actually says
| Source | Nuclear energy (g CO2-eq/kWh) | Status |
|---|---|---|
| Storm van Leeuwen | 78-190 | Not peer-reviewed, refuted |
| IPCC AR5 (2014) | 12 (median) | Peer-reviewed, internationally accepted |
| UNECE (2022) | 5.1-6.4 | UN report, ISO 14040/14044 methodology |
| JRC (2021) | 5-6 | EU scientific knowledge centre |
The 2022 UNECE study compares all electricity sources using identical ISO methodology and concludes that nuclear energy has the lowest life-cycle CO2 footprint of all sources examined — lower than wind, lower than solar, lower than hydropower.
The empirical evidence: France vs. Germany
Theory is fine, but practice is more convincing. Two neighbouring countries, two strategies:
| France | Germany | |
|---|---|---|
| Strategy | Nuclear energy (~70%) | Energiewende (wind + solar) |
| Investment | ~EUR 100 billion (1970s-1990s) | EUR 500+ billion (2000-2024) |
| CO2 intensity of electricity (2024) | 21 g/kWh | 328-363 g/kWh |
| Factor | 1x | 15-17x dirtier |
France decarbonised its electricity grid in roughly 15 years. Germany, after a quarter century of Energiewende and more than half a trillion euros in investment, is still 15 to 17 times dirtier. This is not opinion — these are measured data from France's RTE and Germany's Umweltbundesamt.
The IEA confirms: nuclear energy is essential
The IEA World Energy Outlook 2024 foresees a tripling of nuclear capacity to ~1,000 GWe by 2050 in the Net Zero scenario. The IEA explicitly states that nuclear energy is needed alongside renewable energy to meet climate targets.
Conclusion
Nuclear energy has life-cycle CO2 emissions of 5-12 grams per kilowatt-hour — comparable to wind and lower than solar panels. The claim that nuclear energy "emits 5-10 times more CO2" is based on a non-peer-reviewed source that has been refuted by multiple scientific institutions. Anyone repeating this claim is ignoring the IPCC, UNECE, JRC, and IEA.
Sources
- UNECE (2022), Carbon Neutrality in the UNECE Region: Integrated Life-cycle Assessment of Electricity Sources (link)
- IPCC AR5 WG III, Chapter 7 (2014) (link)
- Lenzen, M. (2008), "Life cycle energy and greenhouse gas emissions of nuclear energy: A review," Energy Conversion and Management (link)
- JRC (2021), Technical assessment of nuclear energy with respect to the 'do no significant harm' criteria (link)
- RTE France, Annual Electricity Review 2024 (link)
- IEA, World Energy Outlook 2024 (link)
- Umweltbundesamt, Strommix und CO2-Emissionen 2024 (link)
