Spatial variation of climate change-induced heat stress risk for dairy cows in Botswana

Abstract

The southern African region is considered a “climate change hotspot” due to its projected substantially warmer and drier future. Climate change projections show that Botswana is warming at a faster pace than the global average. Therefore, there is a need to determine the likely impact of climate change-induced heat stress on dairy farming across ecological regions in the country. This study’s goal was to determine the recent and future spatially differentiated dispersion of heat stress conditions for dairy cattle across Botswana for the recent (2020), near-term (2030), mid-term (2050), and long-term (2070) under the high greenhouse gas emission scenario using the temperature humidity index. Results show an increase in the temperature humidity index ranging from 73.35 to 79.18 in 2020; 76.01 to 81.30 in 2030; 77.76 to 84.16 in 2050; and 79.60 to 85.84 in 2070. Areas in the north, i.e., Northwest, Northeast, and northern parts of the Central and Ghanzi Districts, are projected to record higher maximum temperatures, higher temperature humidity index, a greater number of heat stress days, and experience a higher degree of heat stress severity than those in the south of the country, i.e., Southern, Kgatleng, Kweneng, and Kgalagadi districts. Thus, the intensity of heat stress is projected to increase as you go further north in the country. The spatial variability of heat stress intensity implies that without the implementation of adaptation measures, the entire country could experience dairy farming challenges due to heat stress in the future, exacerbating the already dire dairy production environment in the country. Future policies and programs for developing the dairy sector in Botswana should thus factor in the heat stress challenge to attain the intended objectives.