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

Tropical deforestation accelerates local warming and loss of safe outdoor working hours

“…Work in deforested versus forested settings in Indonesia is associated with heat strain, lower cognitive performance, and declines in labor productivity 10,20,31 as well as an increase in all-cause mortality. 32 Individuals working under heat stress are also more likely to experience occupational heat strain and kidney disease or acute kidney injury. 19,59,60 Globally, high ambient temperatures increase mortality, 61,62 with large increases in heat-attributable excess mortality projected in tropical countries due to global climate change.…”

“…40 Under the highemissions scenario Representative Concentration Pathway 8.5 (RCP 8.5), global annual mean warming of 2 C relative to the present is expected as early as 2057, and as early as 2083 in RCP 4.5, a scenario with lower emissions. 32 Future warming will exacerbate effects on unsafe thermal environments via lost safe work hours, even if we assume that there is no further tropical deforestation-an unrealistically conservative baseline given current trends. 41 At the current population, global climate change of +1-C, +1.5 C, and +2 C beyond 2018 temperatures will increase the total number of people in recently deforested locations experiencing 0.5 h per day of unsafe work time by 5, 6.5, and 7.7 million people, respectively.…”

“…Although the MODIS satellite dataset provides twice daily values for temperature, higher temporal resolution temperature and humidity data are needed to estimate work hours lost. Following the methodology of Wolff et al, 32 we use the fifth generation of the European Center for Medium-Range Weather Forecast atmospheric reanalysis data product 84 to obtain the diurnal (24-h) cycle of temperature and humidity over low-latitude land areas in the years 2003 and 2018. For each grid point over land (30 S-30 N, 120 W-170 E), we calculate the average hourly temperature and relative humidity in 2003 and 2018 by using the local specific humidity from the ERA5 data combined with the diurnal cycle of temperature and the assumption that the amount of water vapor in the atmosphere was constant.…”

“…As in Wolff. et al 32 , we assess lost safe work time due to unsafe work conditions using an implementation of the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV), intended for computation of time-weighted average exposure levels and adapted for use with HI assuming sun exposure. 87 We assume workers are acclimatized, able to rest in the shade, utilize regular single-layer work clothes, conduct 415-W metabolic rate work, based on literature for heavy physical work in agriculture or construction.…”

“…[21][22][23][24][25][26]27 Studies on deforestation and temperature changes have focused on quantifying warming from tropical deforestation at regional scales, 13,28 and the relationship between deforestation and increasing temperatures in the tropics is well established. 4,[7][8][9][10][11]29,30 However, only a few small-scale studies have evaluated deforestation effects on heat exposure and the wellbeing of nearby populations in rural communities, 8,31,32 limiting our understanding of whether these effects extend globally in similar settings across low-latitude countries.…”