Modelling energy and environmental impacts of traditional and improved shea butter production in West Africa for food security

Abstract

This study improves the global application of methods and analyses, especially Life Cycle Assessment (LCA), that properly incorporates environmental impacts of firewood and a social sustainability indicator (human energy) as tools for sustainable human development. Specifically shea butter production processes, common throughout sub-Saharan Africa and crucial to food security, environmental sustainability, and women's empowerment, are analyzed. Many economic activities in the world rely on firewood for energy and labor that aren't included in traditional LCAs. Human energy (entirely from women) contributed 25–100% of shea butter production processes (2000–6100kJ/kg of shea butter) and mechanized production processes had reduced human energy without considerably greater total energy. Firewood accounted for 94–100% of total embodied energy (103 and 172MJ/kg of shea butter for improved and traditional shea butter production processes respectively) and global warming potential and 18–100% of human toxicity of the production processes. Implementation of improved cookstoves modeled in this study could reduce: (1) global warming potential by 78% (from 18 to 4.1kg CO2 eq/kg and 11 to 2.4kg CO2 eq/kg of shea butter for the traditional and improved processes respectively), (2) the embodied energy of using firewood by 52% (from 170 to 82MJ/kg and 103 to 49MJ/kg for the traditional and improved processes respectively), and (3) human toxicity by 83% for the non-mechanized traditional and improved processes (from 0.041 to 0.0071 1,4 DB eq/kg and 0.025 to 0.0042 1,4 DB eq/kg respectively). In addition, this is the first study to compare Economic Input-Output Life Cycle Assessment (EIO-LCA) and process-based LCA in a developing country and evaluate five traditional and improved shea butter production processes over different impact categories. Overall, this study developed a framework to evaluate and improve processes for achievement of the United Nation's Sustainable Development Goals for 2030 particularly to obtain food security.