James Conca, scientist in the field of earth and environmental sciences. Contributor to Forbes: Most people have heard of something called externalities, costs not factored into the price. An energy’s deathprint is a rarely-discussed externality. The deathprint is the number of people killed per kWh produced. There is debate on the absolute numbers, but no one debates on the relative ranking from most dangerous to least. It is notable that in media and legislative discussions, the only time death is mentioned is for nuclear, ironic since it has the lowest deathprint of any source.