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.