Dr Jonathan Cobb, Senior Communications Manager at the World Nuclear Association details why nuclear power could be part of the solution to tackling climate change.

From 30th November, for 2 weeks, thousands of negotiators will meet in Paris for the COP21 climate change conference. They will be joined by tens of thousands more delegates representing non-governmental groups such as environmentalists, businesses, scientists, women, trade unions, youth and religious leaders, along with thousands of journalists. If these people genuinely wish to save the climate, they had best give serious consideration to the future role of nuclear energy.

The COP21 organisers describe the event as crucial, as it needs to achieve a new international agreement on the climate, applicable to all countries, with the aim of keeping global warming below 2°C. A key feature of the latest agreement are Intended Nationally Determined Contributions (INDCs), where governments have declared in advance what steps they are committed to taking to combat climate change. A rather big problem is that the INDCs declared so far do not go far enough.

Many of the INDCs include a description of what each government plans to do in the energy sector, in particular for electricity. Globally, electricity and heat production account for more than 40% of CO2 emissions. That is because much of the world’s electricity is currently generated by burning fossil fuels. However, electricity generation is an important focus for climate efforts, as it is one of the few major sectors where proven technologies are available that can reduce greenhouse gas emissions by the required amount.

According to the latest available data the largest single source of low carbon, non-fossil electricity generation is hydropower, supplying around 16% of the world’s electricity. Second comes nuclear energy, generating about 11% with renewables other than hydro such as wind, solar and biomass, generating around 6%. In combination about one third of global electricity comes from these low carbon sources.

Some countries have already shown the potential to achieve much greater use of low carbon electricity in their electricity generation mixes. Brazil, Sweden, Switzerland and France have all reduced reliance on fossil fuels to less than 20% of supply, as has the Canadian province of Ontario. This has been achieved through combinations of nuclear, large hydro and other renewables.

Generation mixes with low greenhouse gas emissions

Other sectors may prove a lot harder to decarbonise, which places the onus on the electricity sector to lead the way. Electricity may also be used as an alternative energy source in these other sectors. Transport for example is another major source of greenhouse gas emissions. Electric cars are progressing to be a real alternative to petrol and diesel, but to maximise emissions reductions the additional electricity demand needs to be met by low carbon generation. Electric trains require the same. Those traveling to the Paris climate conference by Eurostar will be taking advantage of France’s low carbon generation, primarily from nuclear power plants.

One question sometimes raised is whether all these low carbon generation options are truly low carbon, when the full life cycle of the technology is considered. Nuclear generation, for example, relies on the production of nuclear fuel. Similarly, wind turbines have to be manufactured and then supported by concrete foundations. Large hydro schemes often require flooding of areas of vegetation, which releases methane, a much more powerful greenhouse gas than carbon dioxide. All these activities either may release greenhouse gases, or require energy which may come from fossil fuel sources.

However, many studies show (including our own review of the literature) that the lifecycle emissions for nuclear energy and different forms of renewables, are much less than the emissions arising from burning coal, oil or gas in fossil fuel power plants.

The IPCC notes that “The life cycle GHG emissions per kWh from nuclear power plants are two orders of magnitude lower than those of fossil fuelled electricity generation and comparable to most renewables”

It is necessary to use all available low carbon energy options to achieve the emissions reductions required to avoid the worst effects of climate change. The International Energy Agency has produced a scenario showing what would be required to limit the average level of global warming to 2 degrees Celsius. By the end of this century fossil fuel generation will need to be all but eliminated, with significant reductions by 2050. Nuclear generation is the largest single source of low carbon electricity in this scenario, with an installed capacity of 930 GWe by 2050, up from around 370 GWe today.

The task for governments is not only to agree emissions targets in Paris this December, but also to enact effective policy measures to ensure those targets will be met. Negotiators need to know that nuclear energy is part of the solution to climate change.


Dr Jonathan Cobb

Senior Communications Manager

World Nuclear Association



  1. As more and more people migrate to cities, especially in Asia (5 million per MONTH), those cities with office towers, high rise apts, lighting, and electric mass transit, ultimately hybrid cars, will be powered by nuclear energy, not wind or solar, nor biomass. Dense urban cores lack the open space needed for solar or wind and require power 24/7. Asia hosts 14 of the 20 largest cities in the world.

    We are “fat on fossil” (and choking) so the pathway to a diet is nuclear for urban areas. Solar and wind are fine in rural areas. Biomass and hydro are too vulnerable to drought and flooding.

    But, in the face of cheap gas (for now), and little incentive for GHG savings nor real cost of pollution in electricity prices the market and lenders will NOT lead; governments must. And so they are in Asia where 50 GWs of reactors are under construction with another 100 GWs in siting and licensing stages. Most of the reactors operating today are owned by governments, and most will be built on contract to Governments, not to investor owned utilities.

    And if the USA wants to maintain its UN P5 leadership in this essential technology going forward, it must strike alliances for export and construction overseas, while building 50 GWs of new capacity at home by 2050 to replace an aging fleet.


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