Energy and population elasticity of tornado casualties

Recent work shows that tornado energy provides a useful metric for tornado intensity (Fricker et al. 2015). In this talk, I discuss the relationship between tornado energy and tornado casualties. The relationship is examined by aggregating the tornado reports into spatial clusters on days with many tornadoes. Multiplicative regression models are used to quantify the relationship controlling for the number of people in harms way. Results show that casualties increase by 58% [(45, 63) 95% uncertainty interval] with a doubling of tornado energy and 50% with a doubling of population. These results indicate that changes in tornado energetics, perhaps related to global warming, are as important to the problem of tornado fatalities as is the expanding bull’s-eye effect (Ashley et al. 2014; Ashley and Strader 2016). Results are largely insensitive to changes in the scale of the clusters.  The work is important for emergency managers, insurance companies, and policy makers alike.

Ashley W., Strader S., Rosencrants T., and Krmenec A. 2014. Spatiotemporal changes in tornado hazard exposure: The case of the expanding bull’s-eye effect in chicago, illinois. Weather, Climate, and Society, 6:175–193.

Ashley W., and Strader S. 2016. Recipe for disaster: How the dynamic ingredients of risk and exposure are changing the tornado disaster landscape. Bull. Amer. Meteor. Soc.

Fricker T., and Elsner JB. 2015. Kinetic Energy of Tornadoes in the United States. PLoS ONE 10(7): e0131090. doi:10.1371/journal.pone.0131090