The author is using this as a unit of thermal energy being absorbed, not as a measure of deaths:
> As of March, 2023, on an annualized basis, the EEI was 1.61 Watts per square meter. That might not sound like a lot, but on a global basis it is about equal to the energy released from 13 Hiroshima sized nuclear bombs exploding every second.
That "1.61 Watts per square meter" figure does sound low to someone who thinks in terms of 60 Watt light bulbs. Thinking of it on the scale of nuclear bombs being dropped may give people pause to reflect on the magnitude of the rate of energy being absorbed.