Omitting labor responses underestimates the effects of future heat stress on agriculture

Agricultural labor is highly vulnerable to heat stress. However, existing studies exploring the impacts of future weather conditions on agriculture have primarily focused on crop yields, often overlooking the effects on labor. Here, we incorporate labor response to heat stress into an established model-coupling framework to examine the effects of future weather conditions on agricultural market dynamics, considering both biophysical crop yield and labor productivity responses. Under a scenario with high heat stress and high sensitivity of labor to heat stress, global agricultural labor productivity could decrease by 18% by the end of the century, with especially pronounced effects in Africa, South Asia, and Southeast Asia. Our results highlight the critical role of labor in agricultural production under future weather conditions and its high sensitivity to the choices of General Circulation Models and labor-heat response functions. Labor productivity is sensitive to heat stress, and this relationship has pronounced implications on global agroeconomic futures, particularly at the regional level, according to scenario analyses using the Global Change Analysis Model.