Nuclear Energy against the Climate Change

For a long time, nuclear energy has been demonized, especially following disasters such as Chernobyl and more recently Fukushima. They gave nuclear energy the image of a dangerous tool with nuclear power plants being ticking bombs that should be shut down, and its explosive nature was not matching the contemporary green energy label. But in recent years, a shift in the way scientists and researchers are talking about nuclear energy has taken place, presenting it as a valid solution for climate change. As annual CO2 emissions are constantly on the rise, in order to deliver the growing global production, the world needs to find its energy to produce the necessary amount of goods. But the origin of the said energy plays a huge role in climate change, since fossil fuels are the main cause of it. In this article we will be trying to understand which sector emits the largest part of CO2 responsible for the climate change, then we will analyse the role that the nuclear energy plays in it.

Why is energy the main source of CO2 emissions?

In order to understand the impact of nuclear energy, we have to be able to measure the global emissions of CO2, and the share nuclear energy has in it. Thanks to the collected data of Climate Watch ( ), we can see where the global CO2 emissions are coming from. The presented data covers the time space from 1991 to 2019 and presents five main sectors responsible for the global CO2 emissions. It is clear from this graph that energy emits the largest part of the CO2 emissions, with 75% of global emissions in 2019. Agriculture comes in second representing more than 10% of the global CO2 emissions, and industrial processes, land-use changes and forestry, and waste are the last three sectors responsible for the global CO2 emissions, in much smaller numbers.


The question we should be asking ourselves is, what exactly is the energy sector and why does it emit most of the CO2 emissions? Well, this question is partly answered by « Our World in Data », who measured the global greenhouse gas emissions sector by sector, diving more precisely into the sectors responsible for climate change. The following graph from OWD depicts perfectly all the sectors and how the share of gas they emit precisely, for the year 2016. To prevent severe climate change, we must rapidly reduce global greenhouse gas emissions. The world emits about 50 billion tons of greenhouse gases every year. To determine how we can most effectively reduce emissions and what emissions can and cannot be eliminated with current technologies, we must first understand where the emissions are coming from. We can see the energy use in sectors such as industry (24,2%), transport (16,2%), buildings (17,5%), unallocated fuel combustion (7,8%) etc. But why does the energy consumption emit so much greenhouse gasses? Simply because the source of the energy is not green and durable energy, but harmful fossil energies.


Nuclear energy: a clean and safe way to produce electricity

To support our argument, we will need some empirical evidence, and this is where the study from OWID « What are the safest and cleanest sources of energy? OWID, 2020 » comes in handy. The following study opens more about what kind of energies are used in the sectors we previously described, which ones are emitting greenhouse gasses and which ones are the deadliest to our planet and by extension, to the human race. After a short analysis of the study, we observe that the world energy is produced by the following resources: coal, oil, natural gas, biomass, hydropower, wind, nuclear energy and solar. We can also conclude that the most dangerous source of energy is coal, with 24,6 deaths par terawatt-hour, with 1 terawatt-hour being the annual consumption of 150.000 people in the EU. Coal is also the largest greenhouse gas emitter with more than 820 tons per year. It is no surprise that coal is the highest killer in the energy source family, with its infamous smog’s that pollute our lungs as much as our landscapes. What is both surprising and sad though, is the fact that coal is the source of energy of 36% of the global electricity, it is the most used source of electricity in the world. Oil takes the silver medal, with 18,4 deaths per terawatt-hour and 720 tons of greenhouse gas emissions, while being responsible for only 3% of the global electricity. Then we have natural gas, that has a much lower death rate than the previous two sources, but still has a very high greenhouse emission of CO2, precisely 490 tons per year. This trio composes the fossil fuel energy sources and are responsible for up to 95% of the greenhouse gasses emitted in the energy sector of the total greenhouse emissions. We seem to have found the core of the problem: the fossil fuel energy.And so it’s time to decriminalize nuclear energy, as the given studies supply us of enough results to do so. We can see that nuclear energy is responsible for 10% of the global electricity (it is higher in countries such as France or Norway, where nuclear energy supplies 67% and 30% of the global energy respectively), but has a very low death rate, 0,03 deaths per terawatt-hour to be exact, and emits only 3 tons of greenhouse gasses. An honorable mention would be solar energy, which is responsible for 4% of the global electricity, with a very low death rate of 0,02 deaths and 5 tons of greenhouse gasses emitted per year.


It is very interesting to observe that nuclear energy has the second least death rate of all the sources of energy, being the safest and cleanest source of energy in the world. This idea strongly contradicts the one that the general public has about the nuclear energy. Different surveys show that around the world, the average opinion about nuclear energy, nuclear waste and the dangers of it, is very negative, and often false. For example, eight out of ten respondents wrongly think that all radioactive waste is very dangerous (79%). Then, the survey shows that 74% of respondents consider that the storage of low-level radioactive waste is very risky.

Like all energy-generating technologies, nuclear energy produces waste. There are three types of nuclear waste, classified by their radioactivity: low-level waste, intermediate-level waste and highly contaminated waste. About 90% of the total volume of waste is made up of tools and work clothes that are not very contaminated and contain only 1% of the total radioactivity. It loses most or all of its radioactivity within 300 years and is mostly stored in power plants, where it does not require special shielding like concrete walls or protective clothing for nuclear workers. About 7% is intermediate-level waste, such as used filters and steel components from reactors. This type of waste has been exposed to alpha radiation or contains long-lived radionuclides in concentrations that require isolation beyond several hundred years. This type of waste must be solidified in concrete or bitumen and is mostly buried in shallow deposits on site. Thus, we can manage 97% of nuclear waste very well, but the real problems start with the remaining 3%. This 3% is made up of highly radioactive materials produced as a byproduct of nuclear reactions that occur inside reactors. They come in two forms: spent fuel from reactors and the waste that remains after the reprocessing of spent fuel. In total, there were 370,000 tons of spent fuel in the world in 2013, a third of which was processed. Each year, 12,000 new tons are added to this pile. Safe methods for the final disposal of highly radioactive waste are technically proven; the international consensus is that geological storage is the best option. This information may seem very demotivating when it comes to the efficiency of nuclear energy, but what we can say, considering all of this, is that air pollution from the burning of fossil fuels represents a far greater threat to public health than deep geological repositories of nuclear waste, if safe storage over a long period of time is assumed. The WHO has estimated that around 4.2 million people die each year from air pollution.

On the other hand, if we do decide to build new reactors, they don’t have to be the same giant installations that cost billions. Small Modular Reactors are another option. They are much cheaper and use the latest technologies to improve their safety. There are also designs that promise to consume nuclear waste and convert it into more fuel. They’re known as « breeder » reactors. We have had a lot of experience in developing and operating this waste-burning technology, but the economic situation was never quite right for reactors using this technology to be deployed in large numbers.

 Combining nuclear and renewable energy to fight climate change

Some argue that nuclear energy is a dangerous tool of the 20th century, that should be forgotten and erased, and that humanity should focus on renewables such as solar, wind and hydro. But while renewables are a safe and clean way of obtaining electricity, it is clearly not the most efficient way. For instance, solar and wind energy is highly, if not totally dependent on an external factor: the weather, and during periods such as winter, when electricity consumption is at its peak, they would be insufficient. This issue can be somewhat controlled, for example by storing energy during the summer, and releasing it during winter, but this is risky as reserves might not be sufficient. We need to opt for other ways to create power, such as nuclear energy. Since humanity uses more and more electricity, for example with the rise of electric cars, we will need a very efficient way of getting energy, and that’s where nuclear energy becomes a very useful tool. No energy source is perfect, and they each come with their own challenges, requiring a lot of research and resources. It seems like on their own, neither nuclear nor solar/wind/hydro are ready to replace the fossil fuels completely. Unfortunately, activists on both sides are claiming that their energy is the only one that should be used. I believe that the truth lays somewhere in between, and that we must use the strengths of both nuclear and renewables in order to replace the deadly the fossil fuel energy.

Pasha Mammadov
Pasha Mammadov
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