The effect of deforestation and climate change on all-cause mortality and unsafe work conditions due to heat exposure in Indonesia

Abstract

Background: Previous studies that have focused primarily on urban, industrialized country settings have found that excess heat exposure can increase the risk of all cause mortality, heat-related illnesses, and occupational injuries. Little research has examined how the combined effects of deforestation and climate change on heat exposure can adversely impact population health and work conditions in low latitude, industrializing countries. Methods: We conducted a modeling study using data at 1km2 resolution comparing 2002 and 2018 forest cover and temperature conditions in the Berau Regency, Indonesia. We used spatially explicit population data to estimate impacts of warming between 2002 and 2018, and after applying 1, 1.5, and 2oC of global warming to 2018 temperatures, on all-cause mortality and unsafe work conditions. Results: From 2002 to 2018, deforestation increased mean daily maximum temperatures by 0.95 (95% CI 0.92 to 0.97) oC. Mean daily temperatures increased by a population-weighted 0.86oC, accounting for an estimated 7.3%-8.5% of all-cause mortality in 2018. Unsafe work time increased by 0.31 (95% CI 0.30 to 0.32) hours per day in deforested areas compared to 0.03 (95% CI 0.03 to 0.04) hours per day in areas that maintained forests. Under 2oC of global warming, deforested areas may lead to an estimated 24% of all-cause mortality and result in up to five unsafe work hours per day compared to 2018. Conclusions: Heat effects from deforestation and climate change have already started affecting the health of populations in low-latitude, industrializing countries, and future warming may result in substantial additional health impacts.