Heat-induced labour capacity loss- future climate change scenario prediction

In developing countries that rely heavily on manual labour, heat stress is expected to worsen, affecting health and productivity. No study has been conducted to date on predicting seasonal heat stress and Labour Capacity Loss (LCL) in India; therefore, the present study aims to examine the impact of climatic change scenarios on heat-induced LCL among informal outdoor workers in Southern India. We studied cross-sectional changes in Wet Bulb Globe Temperature (WBGT) and surveyed 1247 workers in five informal outdoor sectors in Tamil Nadu (TN). We use Dunne's empirical approach to measure regional LCL variations throughout three periods till 2099. The results are described using descriptive and multivariate analysis. The results showed that the seasonal WBGTs increase by 1.6 ± 0.2 °C and 2.3 ± 0.2 °C (summer) and 0.7 ± 0.4 °C and 1.4 ± 0.4 °C (winter) under Representative Concentration Pathway (RCP) 6.0 and RCP 8.5, respectively. Perception data collected from this region's workers already shows significantly higher odds of productivity loss with WBGT exposures (Adjusted Odds Ratio (AOR): 1.6; 95 % CI: 1.2–2.1), hot season (AOR: 15.3; 95 % CI: 11.4–20.5), and heavy workload (AOR: 3.4; 95 % CI: 2.4–4.7). While summer WBGTs exceed 30 °C in all three time periods under RCP6.0 and RCP8.5, winter WBGTs surpass safe working conditions in many districts of TN in the third period under RCP8.5. By 2099, under RCP6.0, high/moderate workload summer LCL ranged from 4.5 to 13.3 %, and 1.0–10.1 % under RCP8.5. Our findings show drastic changes in future WBGT and LCL, resulting in significant individual and regional economic losses. To safeguard millions of impoverished informal workers in tropical and subtropical countries, climate mitigation, adaptation, and intervention initiatives are urgently needed.