Global fertility responses to climate-related hazards depend on population disruption, lethality, and hazard type

This paper combines global fertility data with disaster records for 1950–2023 to estimate fertility responses to climate-related hazards, distinguishing between population disruption (affected-rate exposure) and lethality (death-rate exposure).

Climate-related hazards show no systematic fertility response under population disruption, but are associated with persistent fertility reductions under lethality lasting at least 15 years. Such combined estimates, however, mask differences according to hazard type: storms and drought-related hazards drive fertility declines, whereas heat and cold waves are associated with modest fertility increases. Hydrological events show additional negative effects in high-lethality episodes. Over time, disruption-based effects remain weak, and lethality-based effects are consistently negative, although they have lessened in recent decades. Fertility responses vary little across income groups, and non-climate disasters remain fertility-reducing. These results show that fertility responses to climate risk depend on hazard type and lethal severity, rather than on how many people are affected.