How we generate electricity, grow food, heat buildings, travel and manufacture goods are just some of the activities leading to the production of greenhouse gases. For that reason, if you think that we need to reduce emissions, then no one single change can be the total solution.
The Global Calculator is a new tool that can be used to experiment with different options with the objective of selecting a range of actions that would reduce emissions to a level that the model judges would give a good chance of limiting the average global temperature rise to 2C. In addition to making choices for energy production, the calculator also allows users to make choices in areas such as food production and consumption, industry efficiency and transport.
The calculator includes example choices from organisations as diverse as the International Energy Agency, Friends of the Earth, Chatham House, Shell, and the World Energy Council. The amount of nuclear energy in the generation mix is one of the choices that can be made, with options ranging from no nuclear generation up to 1870 GWe by 2050. Notably, all the examples choices, with the exception of Friends of the Earth, include nuclear as part of their actions needed to hit the 2C target. The FoE target is only reached without nuclear by assuming a global population 1.3 billion lower than the central choice and "very ambitious" changes to lifestyle and improvements in energy efficiency. These changes mean that the amount of renewable generation in the FoE scenario is also lower than in many of the others.
We have devised two scenarios, looking at how different levels of nuclear energy deployment can influence achieving the 2C objective.
The first scenario - called Largo - takes as its basis our reference case from the World Nuclear Association Global Fuel Market Report, which assumes just under 3% growth in global nuclear capacity to 2030. Continuing the same growth rate through to 2050 gives a global nuclear capacity of 1030 GWe.
The second scenario - called Allegro - selects the maximum capacity of nuclear generation that the Global Calculator allows, giving a total global nuclear capacity in 2050 of 1870 GWe.
For the rest of the scenario choices, both Largo and Allegro seek to maximise the benefits of low carbon generation, by putting more effort into shifting from gasoline to electric transport options. The scenarios also look for improvements in energy efficiency, at home and in industry.
In addition to more nuclear generation, the Allegro scenario seeks higher levels of effort with renewables, energy efficiency and CCS.
With both scenarios the 2C target is reached, at least according to the judgement of the Global Calculator. However, the area in which they differ most is in the level of effort required after 2050. In the Largo scenario emissions reduction efforts must continue at an "extremely ambitious" between 2050 and 2100. In the Allegro scenario more ambition for nuclear energy in the first half of the century, coupled with greater electrification of transport and a stronger shift away from coal, means the overall level of effort for emissions reductions post-2050 is a more manageable "very ambitious" level.
According to the authors of the Global Calculator, a level 4 effort is making "an extraordinarily ambitious and extreme level of abatement effort." The Allegro scenario would require a significant acceleration in deployment of nuclear energy. But according to the Global Calculator model the reward could be a much more manageable level of effort on avoiding climate disruption in the longer term.