Projected productivity losses and economic costs due to heat stress under climate change scenarios in Brazil

Working under extreme heat conditions threatens health and well-being, which is aggravated by climate change. This study estimated the impact of an increase in global temperature on workability in the Brazilian population and its respective economic costs, under two climate change scenarios, projected over the 21st century. Using daytime Wet Bulb Globe Temperature (WBGT) projections from Coupled Model Intercomparison Project (CMIP6) climate models (SSP2-4.5 and SSP5-8.5 scenarios), we estimated productivity losses in the country's principal labour activities: agriculture, civil construction, the manufacturing industry, services, and informal labour. The economic cost was obtained from daily wages, number of workers and productivity loss. Our results indicate that the North, Northeast and Central-West regions face significant increases in daytime WBGT, frequently surpassing 34 °C in the SSP5-8.5 scenario, which may exacerbate the effects of outdoor activities as they are currently carried out. In agriculture and civil construction, productivity could fall by 90%. Daily economic losses for regulated labour activities could reach USD 228 million under SSP2-4.5 and up to USD 353 million in SSP5-8.5. To reduce these impacts, global mitigation action to curb the increase of global temperature must be implemented, while national public policies that protect workers, such as creating cool spaces, providing regular breaks, adjusting working hours and encouraging hydration, must be adopted and reinforced.