Quantifying Increased Occupational Heat Exposure of Rice Harvest Workers due to Climate Change

Abstract:

Increased temperature and humidity, resulting from global warming, will undoubtedly have a detrimental effect on people’s ability to work safely, especially in tropical regions. A decrease in labour capacity is indicative of physiological strain on workers' bodies, but also has wider economic implications. Previous studies have estimated the large-scale effect of heat and humidity on labour capacity. However, field study data quantitatively linking temperature and humidity to labour capacity are sparse, and limited studies are often applied beyond the occupational context in which the data were collected. One such highly cited field study (Sahu et al 2013) measures the productivity of workers manually harvesting rice in India. By combining this field study data with CMIP6 climate model output, we have analysed the labour capacity impact of heat and humidity on rice harvest labour specifically. We take into account the seasonal and spatial variation of rice harvest labour using crop calendars and maps of cropland extent. We note a linear trend between the labour capacity impact and the global mean surface temperature, and identify the most affected regions. This adds to the argument for strong mitigation of greenhouse gas emissions, and identifies vulnerable regions that require the most adaptation to increasing heat stress on rice harvest workers.