New Paper: Normalized Tornado Damage in the United States: 1950-2011: ‘There is no indication of increasing incidence of tornadoes’

“However, the decreased frequency of high damage events in recent decades as compared to previous decades is a notable feature in the time series and provides strong counter-evidence to claims found in the scientific literature that the atmospheric environment that spawns tornadoes has intensified leading to more intense events on climate time scales (e.g., Trenberth, 2012)

Such claims are commonly found in the popular media and also in the insurance/reinsurance sector where they influence public opinion and decision making in business and government. The most recent review by the IPCC found no basis for claiming an increase (or decrease) in tornado incidence or intensity (IPCC, 2012).”