Regional disparities and seasonal differences in climate risk to rice labour

Charles Simpson,Dann Mitchell,Richard A Betts,Emily Shuckburgh,J Scott Hosking

doi:10.1088/1748-9326/ac3288

Abstract

The 880 million agricultural workers of the world are especially vulnerable to increasing heat stress due to climate change, affecting the health of individuals and reducing labour productivity. In this study, we focus on rice harvests across Asia and estimate the future impact on labour productivity by considering changes in climate at the time of the annual harvest. During these specific times of the year, heat stress is often high compared to the rest of the year. Examining climate simulations of the Coupled Model Intercomparison Project 6 (CMIP6), we identified that labour productivity metrics for the rice harvest, based on local wet-bulb globe temperature, are strongly correlated with global mean near-surface air temperature in the long term (p ≪ 0.01, R 2 > 0.98 in all models). Limiting global warming to 1.5 °C rather than 2.0 °C prevents a clear reduction in labour capacity of 1% across all Asia and 2% across Southeast Asia, affecting the livelihoods of around 100 million people. Due to differences in mechanization between and within countries, we find that rice labour is especially vulnerable in Indonesia, the Philippines, Bangladesh, and the Indian states of West Bengal and Kerala. Our results highlight the regional disparities and importance in considering seasonal differences in the estimation of the effect of climate change on labour productivity and occupational heat-stress.

Highlights

Agricultural workers are especially vulnerable to hot and humid weather, which impacts health and productivity
This leads to underestimation of heat stress in some conditions, we find that long-term trends in Wet-bulb globe temperature (WBGT) are determined mainly by changes in air temperature
Despite the different biases and climate sensitivities of the models, they each show a linear relationship between global mean near-surface air temperature (GSAT) and the rice harvest labour impact

Summary

Introduction

Agricultural workers are especially vulnerable to hot and humid weather, which impacts health and productivity. There are 880 million agricultural workers worldwide (2019 estimate) [1], the majority in lowincome countries (LIC) and lower-middle income countries (LMIC). Field studies have demonstrated the presence of heat strain and related health issues in agricultural workers [2,3,4]. Workers are frequently subject to temperatures in the range considered harmful. To cope with heat stress, workers reduce their work pace, implying a wellbeing tradeoff between productivity and thermal comfort. Outdoor workers especially, will be exposed more frequently to hot and humid conditions in the future due to climate change [5,6,7]

Methods

Results

Discussion

Conclusion