The consensus is that a 1.2oC average global temperature rise is due to a 50% increase in atmospheric carbon dioxide levels emitted from combustion since the beginning of the industrial revolution. The consequences of this are well known in terms of more extreme seasonal weather effects that disrupt the natural world by way of weather instability, such as increased flooding, drought, disease, famine, to name but a few. Effects have intensified more recently due in particular, to accellerated emissions over the past 40 years [1, 2].
Energy consumption (electricity, heat and transport) is responsible for over 70% of our greenhouse gas emissions, so it makes sense to focus on decarbonising electric grids and our heating and transportation systems . Individual lifestyle changes to promote better energy efficiency, eating less meat and planting trees are compromises that help somewhat, but are not enough to realistically slow, stop or reverse carbon emissions; we need a reliable low-carbon energy supply.
While this is not an anti-renewables post, there must be caution against advocating them as a sole solution to our predicament. Firstly, wind turbines and solar panels are land-intensive; and material intensive for the energy they produce. In addition, hydro-power, solar and wind are relatively destructive for the amount of energy they deliver, resulting in a high ecologically destructive imprint from mining and waste disposal. Unpredictability and intermittency of a weather dependent supply cannot be solved by batteries, which store energy for no more than hours. Intermittent sources are backed by methane-intensive gas power, which is expensively managed to fit with peak demand times.
Excess ramping of gas turbines is inefficient and can generate higher emissions due to start-stop idling as opposed to running at a steady rate.
Policy wise, the reality is that when countries close nuclear plants in favour of solar and wind farms, they are invariably replaced by gas .
See the ‘Top Trumps’ comparison of a selection of energy sources below. Limitations of tidal and wave energy are of a similar vein to solar / wind / geothermal, due to natural laws, including low availability and siting issues.
For a realistic low carbon energy policy it is sensible to highlight the relevance of an important scientific property of the source of energy considered, which is called ‘energy density’. Fission of a uranium/thorium atom creates in the order of a million times more energy than the chemical energy released from breaking Carbon-Carbon bonds . So a kilogram of fuel can last a person’s lifetime. In fact, all eco-credentials of nuclear power stem from this high energy density: lower land and material footprint, cleaner air and less waste produced at all stages.
Nuclear waste is managed very cautiously in line with stringent regulations specified by the Office for Nuclear Regulation and there is a public radioactive waste inventory which details waste arising from all nuclear-licensed sites in the UK . Anyone concerned that waste could remain fissionable is invited to read on about a natural reactor, called Oklo, which fissioned underground 2 billion years ago in Gabon. The waste products barely migrated, let alone re-started a fission reaction in more than 50 million lifetimes. Also, obtaining fissile material is less of an issue for terrorists, than the difficulty of creating such a weapon.
For those who trust the data, the problem for nuclear energy is one of perception. Misinformation about nuclear energy stems from cold war political propaganda and also the persistent use of the Linear No Threshold (LNT) model which was unreliably adopted in the 1950s on the assumption that no dose of radiation is the only safe level. The flaws of the model are that:
- We have been exposed to radiation since life first evolved on earth. High-sensitivity radiation detectors show that it’s impossible to completely escape it, and
- plenty of evidence determines that cells can and do repair following low-level radiation exposure
The word ‘mutation’, which relates to cancer in cell biology, has fired imaginations ever since, and inspired some exciting but inaccurate stories for TV shows and Hollywood films. The Scientists for Accurate Radiation Information (SARI) is a concerted international professional exposure of LNT model . SARI formed after the tsunami in Japan in 2011 caused an accidental release at Fukushima Daiichi and local people were unnecessarily relocated and psychologically stressed by false fears, effectively suffering what is known as the ‘nocebo’ effect, the opposite of a placebo. ‘Nocebo’ describes a situation where a negative outcome occurs due to a belief that the intervention will cause harm.
With respect to accident risk assessments; people feel less fearful about a situation if they feel in control, or the hazard has been normalised (e.g. car accidents). The nuclear fear example often cited is that people don’t want another Chernobyl. Yet, apart from the 28 staff and emergency workers killed from direct impact or exposure, even this – the worst nuclear accident – caused, for the most part, an exposure to radiation levels comparable to, or a few times higher than annual levels of natural background. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has reviewed all the published research on the incident and determined that at present, fewer than 28 documented, plus 15 statistical thyroid cancer deaths are likely to be attributable to increased exposure to radiation .
Anecdotal stories from industrial accidents are upsetting, but why those involving the nuclear industry are perceived to be worse than those from other industries is illogical. For example, the Piper Alpha oil rig explosion which also occurred in the eighties, and killed 167 men is rarely brought up in discussions of safety, suggesting a widespread lack of understanding of facts.
As evidenced on the cards above, nuclear is safest. Nothing is completely risk free, so we should stop ignoring real risks while requiring perfection elsewhere.
Scientists include nuclear energy in all pathways to net zero in their Intergovernmental Panel on Climate Change’s 2018 Special Report (15) on Global Warming of 1.5oC . The UK’s current plans only focus on replacing those nuclear facilities due to retire over the coming decade. But we should think bigger by working on full scale deployment of nuclear energy to the grid alongside changes to the wider transport and heating infrastructure.
Climate change and fossil fuels kill millions per year whereas nuclear energy does not.