New Study Finds Surprising Health Benefits of Nuclear Power

by Michael Shellenberger

In recent years, support for and fear of nuclear energy have both increased. A growing number of climate scientists and environmentalists have advocated for nuclear, which is the largest source of low-carbon electricity in the USA and other countries [1]. But the 2011 accident at the Fukushima nuclear plant in Japan also increased popular fears.

Experts have long recognized the negative impact of fossil fuel pollution on public health, and the relative safety of nuclear power. But prior studies have been limited in their ability to directly measure health trade-offs from moving from nuclear to fossil fuels. 

Climate scientist James Hansen and Pushker Kharecha found  1.84 million lives were saved by nuclear  displacing coal over the last half century.

Climate scientist James Hansen and Pushker Kharecha found 1.84 million lives were saved by nuclear displacing coal over the last half century.

Now, a new study in Nature Energy by a young economist at Carnegie Mellon University, finds that the temporary closure of two nuclear plants in the early 1980s led directly to lower birth weights — a key indicator of poor health outcomes later in life [3].

Carnegie Mellon economist Edson Severnini, author of ground-breaking new  Nature Energy  study.

Carnegie Mellon economist Edson Severnini, author of ground-breaking new Nature Energy study.

The author, Edson Severnini, took advantage of a natural experiment to use strict econometric methods to disentangle confounding variables.

Following the 1979 Three Mile Island accident, the Tennessee Valley Authority, a federal electric utility, temporarily closed two nuclear power plants. Severnini shows that power lost from these plants was replaced entirely by coal-powered electricity generation, which increased air pollution.

Exploiting this structural break in the electricity mix, Severnini found both a decline in air quality, and a reduction in birth weights.

Severnini’s methods — which took into consideration the geographical and temporal variation in exposure to the additional pollution — could be used to estimate future health impacts in nations that are closing nuclear plants and replacing them with plants using coal and other fossil fuels such as Germany, Japan, and the USA.

Where the normal operation of coal plants results in significant, measurable health impacts, the Fukushima accident — the second worst in history — will have no quantifiable impact on public health. And yet, in the wake of the 2011 Fukushima accident, Japan closed its nuclear plants and has indicated it will build dozens of new coal plants to replace them [7].

Germany has followed Japan in replacing its nuclear plants with fossil fuels. As a result, Germany’s carbon emissions rose for the second year in a row last year, and coal accounted for 40% of its power generation [8].

While Germany’s solar panels and wind turbines grab headlines, they have proven too unreliable to replace either nuclear or fossil fuels. In 2016, Germany generated less electricity from the sun even after installing more solar panels, and generated just one percent more electricity from wind despite having increased wind capacity by 11% (ref. 9).

Notably, electricity in Germany in 2016 was nearly 10 times dirtier than in France, which receives about three-quarters of its power from nuclear [10].

Nuclear energy peaked as a percentage of global electricity in 1996 at 17.6%, and has since declined to 11.5%. If policymakers don’t act soon, the world could lose twice as much nuclear as it adds between 2017 and 2030 (Fig. 1).

As such, Severnini’s study could play an important role in catalysing further action to keep nuclear plants on-line, and growing their share of the electricity mix, as a way to protect the health of infants, children, and other vulnerable populations.


1. Gafney, J. S. & Marley, N. A. Atmos. Environ. 43, 23–36 (2009).

2. Markandya, A. & Wilkinson, P. Lancet 370, 979–990 (2007).

3. Severnini, E. Nat. Energy 2, 17051 (2017).

4. Black, S. E., Devereux, P. J. & Salvanes, K. G. Q. J. Econ. 122, 409–439 (2007).

5. Hack, M., Klein, N. K. & Taylor, H. G. Future Child. 5, 176–196 (1995).

6. Health Risk Assessment from the Nuclear Accident After the 2011
Great East Japan Earthquake and Tsunami, Based on a Preliminary
Dose Estimation
(World Health Organization, 2013);

7. Japan plans to build 45 new coal power plants in next decade: EIA. S&P Global Platts (3 February 2017);

8. Appunn, K. Germany’s energy consumption and power mix in charts. Clean Energy Wire (7 March 2017); http://go.nature. com/2nCcdij

9. Shellenberger, M. German Emissions Increase in 2016 Due To Nuclear Plant Closure (Environmental Progress, 2017);

10. German Electricity was Nearly 10 Times Dirtier than France’s in 2016 (Environmental Progress, 2017);

11. Energy Progress Tracker (Environmental Progress, 2017);