In December, the US and 194 other countries signed the Paris Agreement, vowing to work together to prevent worldwide temperatures from rising 2 degrees C (3.6 °F) above pre-industrial levels. Temperatures have already risen 0.8 °C (1.4 °F), and the planet is warming at approximately 0.15 – 0.20 °C per decade.
Preventing further rises in temperature won't be easy, but significant changes are necessary to prevent runaway warming and the resulting imminent worldwide disaster (check out my previous blog post on this here). We've promised to curb carbon emissions, but how do we best do that? Nuclear power is a pre-existing technology that also boasts zero greenhouse gas emissions, but it's a controversial option.
How can nuclear power be good?
When people talk about nuclear energy, they are generally referring to the splitting apart of large atoms (usually isotopes of uranium or plutonium). This is called “nuclear fission.†Nuclear fission is especially valuable because it does not emit greenhouse gases. Nuclear energy currently provides 10.9% of the world's electricity, with 76.9% of all electricity in France, and up to 19.5% in the US, supplying millions of people with their daily electric needs, with a negligible carbon footprint.
A worldwide shift to 100% clean renewable energy is, of course, optimal for reducing carbon emissions. Due to problems with battery storage, however, it is not likely possible to immediately shut down every fossil-fuel burning or nuclear-fission energy source to be fully replaced with renewable energy sources.
If we want to mitigate climate change, we must take immediate action to reduce carbon emissions. Though some may want to shut down all nuclear power sources as soon as possible because of safety and waste management concerns, the proper energy infrastructure is not currently in place to replace nuclear with renewable energy. Shutting down nuclear power immediately would create a huge gap in energy resources that other technologies cannot currently fill.
What are nuclear's caveats?
Nuclear energy is famously controversial. With past nuclear accidents like Chernobyl, Three Mile Island, and Fukishima Daiichi, there is concern about the safety of nuclear power plants. Over the years, however, technology for nuclear power plants has evolved so that plants are much safer. New safety measures are incorporated in the construction of new plants, so that future disasters like these are unlikely. Other concerns include health risks to uranium miners. In reality, however, uranium mining is far less risky than traditional coal mining.
Dangerous nuclear waste from reactors can be a problem to store, since it must be safely contained for up to millions of years due to the slow decay rates of some radionuclides. Reprocessing nuclear waste can reduce the amount of waste and generate energy from used fuel, but reprocessing nuclear waste is currently illegal in many countries, including the US, due to concerns about proliferation of weapons-grade material. Nuclear fuel is also limited, and hence non-renewable.
Replacing uranium with thorium as fuel for nuclear power would solve these problems. Thorium reactors are safer, produce much less nuclear waste, and are impractical for weapons development. Thorium is also naturally more abundant than uranium and is an attractive long-term energy option as the fuel is capable of being “self-sustainingâ€. Fusion reactors are another alternative as they are passively safe, free from greenhouse gas production, and produce quickly-decaying waste. Powerful enough to fuel the sun, fusion works oppositely to fission: rather than splitting larger elements into smaller ones, fusion merges smaller elements into larger ones. At this time, however, the technology does not yet exist to build energetically efficient commercial fusion power plants.
The high cost of nuclear power is one its largest obstacles. Nuclear power plants cost billions of dollars, take years to construct, have expensive operating costs, and end up costing much more than the alternatives. Unfortunately, financiers may prefer to put their money elsewhere.
If we are to do everything possible to reduce climate change, it is necessary to maintain our current nuclear power sources until we can reliably replace it with renewable energy sources. In spite of nuclear's reputation, with careful and proper implementation of new and safer nuclear technologies, we can lean on nuclear fission as a carbon-free source of energy for a couple hundred years and on fusion for much longer than that.
About the Author
Hilde Oliver is a PhD student in the Department of Marine Sciences at the University of Georgia, where she studies how extreme melting of Greenland's ice sheet is impacting marine ecosystems. In her spare time, Hilde enjoys eating Korean food, watching Netflix Originals, and hiking around Appalachia. Follow her on Twitter @Hilde_Oliver or shoot her an email at hildeoliver@uga.edu. More from Hilde Oliver.
