Everyone’s heard of the carbon footprint of different energy sources, the largest footprint belonging to coal because every kWhr of energy produced emits about 900 grams of CO2. Wind and nuclear have the smallest carbon footprint with only 15 g emitted per kWhr, and that mainly from concrete production, construction, and mining of steel and uranium. Biomass is supposedly carbon neutral as it sucks CO2 out of the atmosphere before it liberates it again later, although production losses are significant depending upon the biomass. Carbon emissions and physical footprints are known as externalities and are those vague someone-has-to-pay-eventually kind of thing it’s hard to put a value on. Proposed carbon footprint taxes are in the range of $15 to $40/ton of CO2 emitted, but assigning a physical footprint cost depends on the region, ecosystem sensitivities and importance. A hundred-acre wetlands to be flooded by a new dam is worth more to the planet than a barren hundred-acre strip under a solar array in the Mojave (P. Bickel and R. Friedrich, 2005).
But an energy’s deathprint, as it is called, is rarely discussed. The deathprint is the number of people killed by one kind of energy or another per kWhr produced and, like the carbon footprint, coal is the worst and wind and nuclear are the best. According to the World Health Organization, the Centers for Disease Control, the National Academy of Science and many health studies over the last decade (NAS 2010), the adverse impacts on health become a significant effect for fossil fuel and biofuel/biomass sources (see especially Brian Wang for an excellent synopsis). In fact, the WHO has called biomass burning in developing countries a major global health issue (WHO int). The table below lists the mortality rate of each energy source as deaths per trillion kWhrs produced. The numbers are a combination of actual direct deaths and epidemiological estimates, and are rounded to two significant figures.
Energy Source Mortality Rate (deaths/trillionkWhr)
Coal – global average 170,000 (50% global electricity)
Coal – China 280,000 (75% China’s electricity)
Coal – U.S. 15,000 (44% U.S. electricity)
Oil 36,000 (36% of energy, 8% of electricity)
Natural Gas 4,000 (20% global electricity)
Biofuel/Biomass 24,000 (21% global energy)
Solar (rooftop) 440 (< 1% global electricity)
Wind 150 (~ 1% global electricity)
Hydro – global average 1,400 (15% global electricity)
Nuclear – global average 90 (17% global electricity w/Chern&Fukush)