World Nuclear Association Blog

Calculating Carbon Futures

(Collaboration, Communications) Permanent link

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 AgencyFriends of the EarthChatham HouseShell, and the World Energy CouncilThe 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.

Global Calculator


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.

IPCC call for low carbon energy action

(Communications) Permanent link

When the third report from the IPCC, on mitigation of climate change, was published on Sunday the world's media focussed on its key messages - greenhouse emissions are rising, the threat of climate change is getting stronger, serious and radical international action is required, but we can still avoid the worse effects of climate change if we take action now and for the long term.  

But what was released on Sunday was just the "Summary for Policymakers", a 30-odd page negotiated skim of the actual report, which contains more a thousand pages of carefully referenced scientific assessment.

The conclusions of the full IPCC report are clear, the energy supply system is the largest contributor to global greenhouse gas emissions and more action in this sector is required now. The IPCC report says around 80% of our electricity must be supplied by low carbon sources such as nuclear, renewables and CCS by 2050 and to eliminate polluting coal, oil and gas generation by the end of the century.

IPCC Gases

The IPCC concludes that no single mitigation option in the energy supply sector will be sufficient to hold the increase in global average temperature change below 2°C above pre‐industrial levels. Embracing all options will give us the greatest chance of avoiding the harmful effects of climate change in the most cost-effective way.

Nuclear energy is recognised as having some of the lowest greenhouse gas emissions for each unit of electricity generated, even when the full lifecycle emissions are included. Average emissions from nuclear are 12 grams of CO2 per kWh, compared to 11 gCO2/kWh for onshore wind, 12gCO2/kWh for offshore wind, 24 gCO2/kWh for hydro and 28-47 gCO2/kWh for solar. Biomass has no direct emissions, but infrastructure and supply chain emissions averaged a significant 230gCO2/kWh. Emissions for gas and coal averaged 490 and 920 gCO2/kWh respectively. Carbon Capture and Storage (CCS) helped reduce fossil fuel emissions, but even with CCS fossil fuel emissions were between 160-220 gCO2/kWh.

For uranium resources, the IPCC report notes that if all conventional uranium occurrences are considered there would be enough uranium to meet current levels of demand for 250 years. Closing the nuclear fuel cycle with reprocessing and recycling of fuel through fast reactors could extend that by more than 50 times (to more than 12,500 years) and reduce the amount of waste generated and disposal required. Thorium too could extend the nuclear resource further.

Tackling climate change and weaning ourselves off our addiction to fossil fuels for electricity generation can seem daunting. But as has been demonstrated by France, a commitment to nuclear energy, in partnership with renewables, can virtually eliminate fossil fuels from electricity generation in little more than two decades - and supply some of the lowest cost electricity in Europe.

Nuclear energy supplies low carbon electricity reliably and affordably. The world needs nuclear energy to tackle climate change.