Necessary Power: The Case for Nuclear Energy in Climate Policy

Introduction

Nuclear power is a method of generating electricity through controlled nuclear fission reactions, in which the nuclei of heavy atoms such as uranium-235 are split to release enormous quantities of heat, which then drives steam turbines connected to generators. First developed for commercial electricity production in the 1950s — with the United States opening its first full-scale nuclear plant at Shippingport, Pennsylvania in 1958 — nuclear energy has since grown into a technology supplying roughly 10 percent of the world's electricity as of the early 2020s. Yet despite this track record, nuclear power remains one of the most politically and emotionally contested energy sources in modern policy debates. This essay argues that nuclear energy must be a central pillar of any serious strategy to address climate change, because it is the only proven low-carbon technology capable of generating large-scale, reliable baseload electricity without dependence on weather or geography. The risks associated with nuclear power — real as they are — have been systematically overstated relative to the far graver and more immediate danger of unchecked carbon emissions.

The core case for nuclear energy begins with a simple and brutal arithmetic: decarbonizing the global electricity grid quickly enough to limit warming to 1.5 degrees Celsius above pre-industrial levels requires every available low-carbon tool, and nuclear is among the most potent. The Intergovernmental Panel on Climate Change (IPCC), in its Sixth Assessment Report released in 2022, identified nuclear energy as one of several low-carbon technologies whose expanded deployment is consistent with limiting warming to 1.5°C. The IPCC's analysis characterized nuclear power's lifecycle greenhouse gas emissions — estimated at roughly 12 grams of carbon dioxide equivalent per kilowatt-hour — as comparable to wind energy and far below natural gas or coal, which emit hundreds of times more per unit of electricity produced. These numbers are not marginal; they are transformative.

The Low-Carbon Imperative

The scale challenge is equally important. Global electricity demand is projected to roughly double by 2050 as transportation, heating, and industrial processes are electrified to reduce fossil fuel dependence. Meeting that demand with variable renewable sources alone — primarily wind and solar — requires either enormous battery storage infrastructure that does not yet exist at the necessary scale, or acceptance of grid instability. Nuclear power produces electricity continuously, at high capacity factors typically exceeding 90 percent, regardless of season, time of day, or regional geography. As energy economist Jesse Jenkins and colleagues argued in research published through MIT's Energy Initiative, achieving deep decarbonization at lowest cost almost invariably involves a significant role for firm low-carbon electricity, a category nuclear naturally fills. The specific implication is that retiring existing nuclear plants — as Germany did following the 2011 Fukushima accident — effectively forces a return to fossil fuels in the short and medium term, a substitution whose climate cost is concrete and measurable.

Opposition to nuclear power has historically centered on safety, and the concern is understandable given the visceral images associated with accidents at Chernobyl in 1986 and Fukushima Daiichi in 2011. But understandable is not the same as proportionate. When mortality rates are calculated per unit of energy produced, nuclear power consistently emerges as one of the safest energy sources ever deployed, safer than coal, oil, natural gas, and in most analyses even comparable to wind and solar when full supply-chain hazards are included.

The Safety Record in Comparative Perspective

The Chernobyl disaster, the worst nuclear accident in history, is estimated by the World Health Organization to have directly caused approximately 30 deaths in the immediate aftermath, with a longer-term projection of up to 4,000 premature deaths from radiation-related cancers — a figure that remains contested but represents an upper-bound estimate. The 2011 Fukushima Daiichi accident, triggered by a magnitude 9.0 earthquake and resulting tsunami, caused no confirmed radiation-related deaths, though the evacuation process itself resulted in significant mortality among vulnerable populations. Contrast these figures with the routine mortality from fossil fuel combustion: the World Health Organization has estimated that outdoor air pollution — driven overwhelmingly by burning fossil fuels — causes approximately 4.2 million premature deaths globally each year. The statistical comparison is stark. As energy researcher Hannah Ritchie has argued, the data consistently show that the public perception of nuclear risk is dramatically out of proportion with its actual mortality record compared to the energy sources it would replace.

Modern reactor designs reinforce this case. Generation III and IV reactor concepts incorporate passive safety systems — designs that use gravity, convection, and other physics-based mechanisms to cool reactors without requiring active human intervention or electrical power. The AP1000 reactor design, developed by Westinghouse, and various small modular reactor (SMR) architectures under development represent a generational improvement over the designs that failed at Chernobyl and Fukushima. The policy implication is not that nuclear accidents are impossible, but that the relevant comparison is not nuclear power versus a hypothetical risk-free world; it is nuclear power versus the demonstrated, ongoing lethality of fossil fuel combustion.

The strongest honest objection to nuclear expansion is not safety — it is economics and the unresolved challenge of long-term radioactive waste disposal. These concerns deserve serious engagement rather than dismissal.

Economics, Waste, and the Real Obstacles

The economics of nuclear construction in Western countries have been genuinely troubled in recent decades. Projects such as the Vogtle Units 3 and 4 in Georgia — the first new nuclear reactors built in the United States in roughly three decades — came online years behind schedule and billions of dollars over their original budgets. Plant Vogtle's cost overruns, which pushed the project toward approximately $35 billion total, represent a real cautionary data point. Similar cost problems plagued the Hinkley Point C project in the United Kingdom. Nuclear scholars and energy economists, including those at the Brookings Institution, have noted that regulatory complexity, loss of construction expertise over decades of minimal building, and first-of-a-kind costs all contribute to this pattern. These are genuine barriers, not invented ones.

The waste problem is similarly real. High-level radioactive waste from nuclear reactors remains hazardous for thousands of years, and no country has yet opened a permanent deep geological repository, though Finland's Onkalo facility is progressing toward becoming the first. The United States has been particularly stalled on this question since the political collapse of the Yucca Mountain repository project. The volume of high-level nuclear waste produced globally, however, is far smaller than most people assume — the entire history of American commercial nuclear power has produced roughly 90,000 metric tons of spent fuel, a quantity that would fit within a single large warehouse. The hazard is real and long-lived, but it is bounded, localized, and physically manageable in ways that atmospheric carbon dioxide — which disperses globally and persists for centuries — is not.

The economic problem, moreover, is not inherent to nuclear technology; it is a function of the specific regulatory and industrial environment in which nuclear has been built. South Korea and France have historically built nuclear capacity at far lower cost per unit than the United States, suggesting that with sustained commitment and standardized design, the economics can be improved. The emergence of small modular reactors, which promise factory-construction efficiencies and reduced upfront capital costs, offers a plausible path toward more competitive nuclear economics in the coming decade.

Conclusion

The urgency of the climate crisis makes the opportunity cost of excluding nuclear power prohibitive. Every year that a functioning nuclear plant is shut down rather than operated, low-carbon electricity is replaced — in practice, not in theory — by natural gas or coal. Every year that new nuclear construction is delayed by regulatory paralysis or political opposition, the energy transition is slower than it needs to be. The evidence from the IPCC's own scenarios, from energy systems modeling, and from the real-world experience of countries that have chosen different paths, all points in the same direction: nuclear energy is not a relic of the twentieth century to be managed into retirement. It is an essential tool for the twenty-first century's defining challenge.