Natural hazards of medium intensity but high frequency (severe convective storms, hail, localized floods) that now represent the majority of global insured losses.
The term secondary perils denotes, in catastrophe modeling jargon, natural hazards that differ from primary perils (tropical cyclones and earthquakes) by their lower unit intensity but markedly higher frequency of occurrence. The main sub-categories are severe convective storms (SCS), including hail, lightning and tornadoes; localized fluvial and pluvial flooding; small-to-medium-scale vegetation fires; heavy snowfall and ice storms; and certain extratropical wind events. Long underestimated by catastrophe models, which concentrated their calibration resources on primary perils, secondary perils have progressively represented a growing share of global insured losses. In 2023 they accounted for the majority of the 142 loss-generating catastrophes recorded that year, according to Swiss Re. Their diffuse nature (losses often between one and five billion dollars per event) makes them difficult to cover with cat bonds or high-layer XL treaties classically calibrated to primary perils. The increasing prominence of secondary perils under climate change (intensification of convective storms, extension of fire seasons) is forcing actuaries to recalibrate their correlation matrices and PML estimates on these historically under-priced perimeters.
In 2023, hailstorms in the United States alone caused over 50 billion dollars in economic damage, exceeding hurricane losses the same year. Most of these claims accumulated in the XL programs of property and agricultural insurers, whose catastrophe models had not anticipated this accumulation severity across such a geographically dispersed perimeter.
secondary perils, risques de fréquence moyen, risques convectifs