Greenhouse gas emissions avoided through use of nuclear energy

There are many different electrical generation methods, each having advantages and disadvantages with respect to operational cost, environmental impact, and other factors.

Each generation method produces climate-warming greenhouse gases in varying quantities through construction, operation, fuel supply and decommissioning. Some generation methods such as coal fired power plants release the majority of emission when their carbon-containing fossil fuels are burnt, producing carbon dioxide. Others, such as wind power and nuclear power, give rise to much less emissions, these being during construction and decommissioning, or mining and fuel preparation in the case of nuclear.

Accounting for emissions from all phases of the project (construction, operation, and decommissioning) is called a lifecycle approach. Comparing the lifecycle emissions of electrical generation allows for a fair comparison of the different generation methods on a per kilowatt-hour basis. The lower the value, the fewer emissions are released.

The World Nuclear Association  carried out a review of over twenty studies assessing the greenhouse gas emissions produced by different forms of electricity generation. The results summarised in the chart below show that generating electricity from fossil fuels results in greenhouse gas emissions far higher than when using nuclear or renewable generation.

Greenhouse gas emissions from electricity generation


In 2018 the world's nuclear power plants supplied 2563 TWh (billion kWh) of electricity. The following table shows the additional emissions that would have been produced if fossil fuels had been used to generate the same amount of electricity.

  Average lifecycle GHG emissions (tonnes/GWh) Emissions produced from generating 2563 TWh of electricity Additional emissions avoided through use of nuclear electricity in place of fossil fuel
Lignite 1054 2701 million tonnes CO2 2627 million tonnes CO2
Coal 888 2276 million tonnes CO2 2202 million tonnes CO2
Oil 733 1879 million tonnes CO2 1805 million tonnes CO2
Natural Gas 499 1278 million tonnes CO2 1204 million tonnes CO2
Nuclear 29 74 million tonnes CO2 -

Comparison of emissions from nuclear and renewable generation

The World Nuclear Association review of lifecycle emissions from nuclear and renewable generation showed that lifecycle emissions from all the major forms of renewables (solar, wind, biomass, hydroelectric) and nuclear were similiar. Replacing generation from nuclear or renewables with fossil fuels would lead to similar rises in greenhouse gas emissions.

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