Extreme Weather Events Exposure and Fertility Outcomes: Insights from the UK Household Longitudinal Study

The implications of climate change are becoming increasingly visible through its multifaceted effects, including the rising frequency and intensity of extreme temperatures and weather events such as floods, droughts and sea level rise. This study integrates longitudinal survey data from Understanding Society (2009–2023) with high-resolution flood and temperature records across the United Kingdom to examine how exposure to heatwaves and floods relates to the likelihood of conception among childless individuals of reproductive age. Using monthly-level discrete-time event history models, the analysis accounts for demographic, socio-economic, and contextual confounders, and further investigates the moderating role of pre-existing climate change attitudes and behaviours. The results show that exposure to both types of natural hazards is associated with a temporary reduction in the monthly probability of conception. Heatwaves, in particular, show a strong and highly significant association, with conception probabilities declining sharply during months of exposure. Floods show a weaker yet still negative association, observed in the six months immediately following the event. Furthermore, environmental behaviours appear to play a moderating role in the case of floods: only individuals reporting environmentally friendly behaviours experience a temporary decline in conception probabilities after flood exposure, followed by a modest rebound thereafter. By uniquely combining individual-level panel data with localized climate information, this study goes beyond intention-based analyses to reveal how climate shocks relate to actual fertility behaviour. Overall, these findings demonstrate that climate change constitutes not only an environmental or economic challenge, but also a demographic one, with meaningful implications for fertility behaviours.