The effect of deforestation and climate change on all-cause mortality and unsafe work conditions due to heat exposure in Berau, Indonesia: a modelling study

Abstract

BackgroundPrevious studies focusing on urban, industrialised regions have found that excess heat exposure canincrease all-cause mortality, heat-related illnesses, and occupational injuries. However, little research has examinedhow deforestation and climate change can adversely affect work conditions and population health in low latitude,industrialising countries. MethodsFor this modelling study we used data at 1 km²resolution to compare forest cover and temperature conditionsin the Berau regency, Indonesia, between 2002 and 2018. We used spatially explicit satellite, climate model, andpopulation data to estimate the effects of global warming, between 2002 and 2018 and after applying 1·0°C, 1·5°C,and 2·0°Cof global warming to 2018 temperatures, on all-cause mortality and unsafe work conditions in the Berauregency, Indonesia. FindingsBetween 2002 and 2018, 4375 km²of forested land in Berau was cleared, corresponding to approximately 17%of the entire regency. Deforestation increased mean daily maximum temperatures by 0·95°C(95% CI 0·97–0·92;p<0·0001). Mean daily temperatures increased by a population-weighted 0·86°C, accounting for an estimated7·3–8·5% of all-cause mortality(or 101–118 additional deaths per year) in 2018. Unsafe work time increased by 0·31 hper day (95% CI 0·30–0·32;p<0·0001) in deforested areas compared to 0·03 h per day (0·03–0·04; p<0·0001) inareas that maintained forest cover. With 2·0°C of additional future global warming, relative to 2018, deforested areascould experience an estimated 17–20% increase in all-cause mortality (corresponding to an additional 236–282 deathsper year) and up to 5 h of unsafe work per day. InterpretationHeat exposure from deforestation and climate change has already started affecting populations in lowlatitude, industrialising countries, and future global warming indicates substantial health impacts in these regions.Further research should examine how deforestation is currently affecting the health and wellbeing of localcommunities.