The National Geographic documentary film ”Before the Flood”, by Academy Award winner Leonardo DiCaprio, is an important collection of information about climate change and the associated threats to humanity. The film deals admirably with several myths and misconceptions about climate change, some of them being actively pursued by climate change deniers. There are, however, some statements in the film that are simplified and deserve further explanation. Furthermore, while the film does not mention nuclear power at all, the related web page contains a number of statements on nuclear power which are incorrect or taken out of context. This report comments on those statements, with the hope that the film makers will change their stance on the issue. Links to the film and the related web page are found in the end of the report, together with references referred to in the comments.
Comments on the film
In the documentary film ”Before the Flood”  there is an interview with the Swedish scientist Johan Rockström, professor and director of Stockholm Resilience Centre, where he makes some statements about renewable energy.
Rockström: ”We actually have the proof [on high tech clean energy solutions]. You wake up in Germany Saturday morning, you are likely to get 30 percent of the electricity from solar and wind.”
Comment: Rockström’s statement is almost correct. In 2015 German electricity from renewables on average made up 30 percent, out of which 13 percent was from wind power, 8 percent from biomass, 6 percent from solar, and 3 percent from hydro power . At any given moment this may vary, depending on the weather.
It should be noted that Germany has essentially not reduced its climate emissions from the energy sector since 2009, in spite of a remarkable increase in renewables . The reason is that the use of fossil fuels has not decreased and nuclear power is slowly being phased out, thereby canceling the positive climate impact from the increased use of renewables . Replacing one low carbon source of power with another is not a good recipe for reducing the climate impact, it would be much better to close down coal and gas before nuclear power.
Regarding proof for clean energy solutions, Rockström could have looked at his native Sweden where more than 90 percent of the electricity has been low carbon since the mid-1980’s. As a comparison, the climate emissions from electricity production in Sweden are about 20 g CO2-equivalents per kWh, while in Germany they are around 450, see Table 1.
Figure 1. Wind data for Denmark 2015 . As seen the electricity from wind can vary from full potential down to almost nothing.
Comments on the web page
Although the film does not mention nuclear power at all, there is a section on the related web page that does. The page, titled ”Nuclear Power – Not the Answer”  has a text written by Kelly Rigg, director of The Varda Group for Environment and Sustainability. It is remarkable that a film that deals with the myths and misconceptions about climate change, repeatedly referring to the science, has a text about nuclear power that is full of errors and issues taken out of context. Here are comments and corrections of the statements by Rigg.
Rigg: ”Certain myths and misconceptions simply refuse to die. The myth that nuclear power will help solve the climate crisis is a case in point.”
Comment: A running nuclear power plant is essentially free from carbon emissions. In a life-cycle perspective, where construction of the plant itself, uranium mining, enrichment, fuel manufacturing, plant decommisioning and handling of spent nuclear fuel are taken into account, nuclear power is still one of the energy sources with lowest climate impact per kWh of electricity, similar to wind and hydro power, and lower than solar PV .
On a global scale nuclear power is at present the second largest low-carbon energy source after hydro power, see Fig. 2. While wind and solar are growing at an impressive rate they still have a long way to go before being larger than nuclear or hydro, and fossil fuels still make up 86 percent of the global energy supply . Nuclear power alone will not solve the climate crisis, but it is also very unlikely that renewables can do it by themselves. The IPCC Fifth Assessment Report says :
”Technology options include a range of energy supply technologies such as nuclear power, solar energy, wind power, and hydroelectric power, as well as bioenergy and fossil resources with carbon dioxide capture and storage.”
This statement, and reasoning in other parts of the report about costs and risks, gives the conclusion that it is very difficult to stay below 2 degrees increase of the global temperature if some of the options are excluded. So to claim that nuclear power has no role to play is at best a display of ignoring the urgency of the situation.
Rigg: ”In the real world, the deployment of renewables is growing rapidly, while nuclear power production (with the exception of China) is shrinking. In 2015, wind and solar PV had another record breaking year, accounting for around 77% of new power installations worldwide. By comparison, nuclear output grew only by 1.3%, and that was solely as a result of growth in China.”
Comment: In the real world, we need to reduce the use of fossil energy as fast as possible. It is unfortunately a common mistake to make statements about renewables versus nuclear when the immediate discussion need to be about low-carbon vs fossil, and how to meet the double challenge of increased use of energy while simultaneously avoiding potentially disastrous effects from climate change. The rapid increase in renewables should be applauded, but to reject the positive climate impact from existing and future nuclear and claim that it is not needed is to ignore the reality, as shown in Fig. 2.
Regarding the numbers given by Rigg, installed capacity is not the same as production capacity. For instance the total installed capacity of solar PV in Germany in 2015 was 20 percent while the production of electricity from the same solar PV was 6 percent. For comparison, German nuclear power capacity was 6 percent while supplying 14 percent of the electricity [2, 13]. A failure to understand the need for baseload power supply, and dismissing one viable option because there is too little of it being installed presently, is not helping in solving the climate issue and shows an unfortunate ignorance from those making such statements. The amount of renewables installed each year is impressive and desperately needed, but is not enough in order to stay below 2 degrees global temperature rise . Therefore we need every low carbon option on the table, including nuclear power.
Figure 2. By 2015 the global supply of low-carbon energy sources had reached 14 percent of the world total, the rest is coal, gas and oil. Data from BP Statistical Review of World Energy 2016 .
Rigg: ”Given that nuclear plant operators can’t get insurance – the state has capped liability for operators – taxpayers will foot the bill every time.”
Comment: Most nuclear power companies have some sort of damage compensation funds which is regulated by national law and international agreements such as the Paris and Vienna conventions [27, 28]. Such funds presently do not cover costs at the level of Fukushima, and it is considered reasonable for governments to cover such so-called top risks for activities that are of national interest but have an associated small probability of large scale damage. Arguments against the government taking such top risks, which rightfully can be considered a subsidy, also mean that other activities, such as large hydro power dams and petrochemical industries, with potential damage of the same magnitude, can not be considered acceptable, but such discussions are almost never heard. A global risk fund for all nuclear power plants, or regional risk funds for activities with large potential costs, could be a way to achieve a full coverage even for Fukushima-scale accidents. The costs for such funds would be equivalent to a few tenths of a US cent per kWh of electricity , but it requires political willingness in order to realize such an arrangement.
Rigg: ”In the real world, the devastating impacts of climate change remind us daily that decarbonizing our economy is a matter of the gravest urgency. New nuclear power plant construction is characterized by lengthy delays and massive cost overruns – often by years, in a number of cases by decades. The fact is, increasing energy efficiency and rapidly scaling up the deployment of renewables are the only way to bring down emissions quickly enough to stave off a full-blown climate catastrophe.”
Comment: Kelly Rigg is correct, the need for a fossil free society is urgent in view of the climate issue. Unfortunately we are not even close to building renewables fast enough yet. But France, Sweden and a few other countries managed to build their nuclear fleets at the pace that would be necessary in order to decarbonize the electricity supply globally [14, 30]. This does not mean that we should do it with nuclear only, rather that we need to speed up the construction of both renewables and nuclear. Energy efficiency and solutions such as carbon capture may also be necessary. And even more important, those who care about the climate issue should work actively against premature closure of fully functioning nuclear plants, especially as there is no benefit for the climate to replace them with renewables. In the US, the recent closure of four nuclear plants means a loss of low carbon electricity equivalent to the entire US addition of solar power, and within the states where they have closed down the use of fossil fuels has increased .
Rigg: ”But let’s get one thing straight – nuclear power is a false solution. Nuclear is dangerous, slow and expensive.”
Comment: Let’s get one thing straight – nuclear power is a safe existing solution, together with renewables and other means of combatting global warming. It is very dangerous to exclude it if we are to avoid devastating consequences caused by a too slow transition away from fossil fuels. And according to the IPCC it will also be more expensive.
Rigg: ”Who knows, maybe one day in the future we’ll get a safe, clean, cheap version of nuclear power, …”
Comment: We have some good news for Kelly Rigg, there are several reactor designs that address the percieved issues of safety and waste problems. These reactors have passive safety systems, reuse of the existing spent nuclear fuel, and less waste to handle for long time spans. The reuse of nuclear fuel enables a source of energy for several centuries. Some of these reactor concepts have not materialized yet, others have been available for a long time but were stopped from further development due to political decisions based on unfounded fear (Superphenix in France, and the Integral Fast Reactor in the USA are notable examples). In order to address these issues there is also a need for a complete system handling the fuel (the so called Generation-IV concept), and there are some technical challenges to solve in order to make the system economically feasible. But it is remarkable that people who do not believe in the possibility of further technical development of nuclear power often display an unlimited optimism for overcoming the challenges with a 100 percent renewable energy system.
Rigg: ”…or maybe even “dilithium crystals” that can power space travel.”
Comment: It may come as a surprise to Kelly Rigg, but exploration of the outer parts of the Solar system relies on nuclear power in the form of plutonium batteries, as there is not enough sunlight available for using solar cells . There are also several space rocket designs proposed that use nuclear fission that heats hydrogen gas for the propulsion. We do not need dilithium crystals, space travel is already possible with the help of nuclear technology.
Rigg: ”Unlike nuclear, which requires the mining of uranium, renewable technologies simply harness what is freely available.”
Comment: Renewable energy also requires the use of finite resources, including mining of metals and other materials that give a large environmental impact. Furthermore, large scale deployment of renewables may lead to bottlenecks in the supply of certain resources . While the wind and the sunshine is free, the technologies to harness them come with a cost. In the real world somebody needs to pay that cost.
Rigg: ”And in the time it takes to build a single new nuclear plant we could build thousands of new solar and wind plants.”
Comment: We can build nuclear as fast, or faster, than we can build the equivalent amount solar and wind plants. But we need to do both, and we need everything available if we are to take the climate issue seriously. In China the use of coal seems to have reached the peak level. This is very welcome news, but the challenge remains to bring the use of fossil fuels to zero. The arguments given by Kelly Rigg show a willingness to prefer nuclear phaseout before solving the climate issue. This is indeed a very dangerous game to play for anybody who claims that decarbonization is a matter of the gravest urgency.
Mattias Lantz – Uppsala University and Analysgruppen