66 Environmental Impacts of Animal-Sourced Foods: Historical Trends and Future Opportunities

Abstract

Abstract There is considerable debate within the scientific literature surrounding the role of animal-source foods (ASF) in sustainable food systems. Much of that debate centers on the environmental impacts of ASF. Although exact values vary with geographical location, data source, temporal focus, production strategies, and other factors, it is without doubt that ASF contribute notably to the environmental impacts of agriculture systems. The contributions of animal agriculture to environmental impacts globally has been used repeatedly as justification to downscale or eliminate consumption of ASF; however, this logic is predicated on the assumption that omission of livestock from the food production system would result in impact reductions proportional to current contributions. Simulations of the potential impacts of animal agricultural removal from the U.S. suggest this assumption may not hold. As such, there is a need to better understand the nature of ASF environmental impacts, to explore scenarios intermediate to current production practices and wholescale omission of ASF, and to prioritize potential strategies to address the societal challenges presented by the environmental impacts of ASF. These objectives of this work are to: 1) review the importance of critical context clarifications when discussing the environmental impacts of ASF; 2) explore the historical changes in the environmental impacts of ASF; and 3) highlight emerging areas of opportunity to enhance the environmental impacts of ASF. When considering the impact of ASF it is critical to contextualize discussions within geographical, temporal, and production-relevant scopes as relative impacts and conclusions drawn vary dramatically across different levels of these factors. Within the context of historical, U.S. agricultural systems, industry consolidation and productivity enhancement has contributed to notable improvements in the environmental footprints of ASF; however, absolute emissions in some industries are constant or increasing with time. Future efforts to enhance environmental impact should focus on productivity enhancement and direct impact mitigation to simultaneously address environmental footprints and absolute impacts.