Escalating Heat Stress And Outdoor Labor Productivity Loss In The Arabian Peninsula: A Five-Decade Analysis Of Climate Change Impacts

Abstract The Arabian Peninsula is experiencing increasing extreme heat, driven by rising global temperatures, with profound implications for outdoor labor productivity. This study investigates the spatiotemporal evolution of Wet Bulb Globe Temperature (WBGT) calculated from the ERA5 data at a 0.25° × 0.25° resolution from 1974 to 2023. The outdoor labor productivity under light, moderate, and heavy workloads is assessed following ISO/DIS 7243 guidelines, while population exposure is evaluated using LandScan data. Results show a pronounced increase in WBGT over the past five decades, with annual levels rising by up to 1.5 °C and summer levels by 1.0 to 1.5 °C. Coastal areas experience the highest WBGTs, surpassing 28 °C in the summer. In terms of productivity, Heavy workloads exhibit the most severe productivity losses, declining from 94% in 1974 to under 88% in 2023, with an annual decrease of 0.136%. Moderate and light workloads show smaller declines of 0.085% and 0.041%, respectively. Coastal and urban locales emerge as hotspots, where midday productivity losses can reach 30% for heavy work. Bivariate analyses indicate an inverse relationship between productivity and temperature/humidity. On the other hand, higher wind speeds mitigate some heat stress effects. These findings underscore the need for urgent policy action, including the implementation of adaptive work-rest schedules, investment in cooling infrastructure, and the development of protective technologies to safeguard labor productivity in warm climates. Graphical Abstract This graphical abstract provides a visually compelling summary of research investigating the intensification of heat stress and its implications for labor productivity across the Arabian Peninsula. It encapsulates the core methodology and findings of the study, enabling readers to quickly grasp the significance of the work without needing to delve into the full manuscript. Central to the visual is the spatiotemporal analysis of Wet Bulb Globe Temperature (WBGT) derived from ERA5 reanalysis data at a 0.25° × 0.25° resolution spanning 1973–2023. A series of maps illustrate the annual and summer WBGT trends, with coastal zones consistently exceeding 28 °C during summer months. The integration of LandScan population data allows for the identification of high-exposure regions. Productivity loss across different light, moderate, and heavy workload intensities is assessed using ISO/DIS 7243 guidelines. Temporal trends reveal a marked decline in productivity for heavy workloads, dropping from 94% in 1974 to below 88% by 2023, with smaller declines for lighter tasks. Additional charts show the diurnal variation in productivity and highlight midday periods as critical stress windows. A bivariate map visualizes the combined effect of temperature and humidity on productivity, indicating wind speed as a mitigating factor. This visual narrative highlights the increasing occupational heat risk, particularly in urban and coastal areas. It underscores the necessity for adaptive measures such as rest-work cycles and climate-resilient infrastructure.