Livestock production and the global environment: Consume less or produce better?

Abstract

Whereas the Green Revolution was a concerted political and scientific response to rapidly growing populations, the Livestock Revolution currently underway in developing countries is driven by growing incomes or the world’s emerging middle class (1). Recently, a number of studies have underscored the impact of livestock on the global environment, including anthropogenic climate change (2), nitrogen cycles (3), and phytomass appropriation (4). In a paper published in PNAS, Pelletier and Tyedmers argue that the livestock sector will soon reach, or exceed, recently published sustainability thresholds in the areas of climate change, reactive nitrogen mobilization, and anthropogenic biomass appropriation and that curbing livestock sector growth should be a major focus in environmental governance (5). We agree that the current environmental impact of livestock is large, but it can be significantly attenuated. We show that some countervailing trends are already in place that have the potential to reduce environmental impact drastically, notably the shift to monogastrics and continued efficiency gains in the production of feed and livestock. These tendencies will help mitigate livestock’s global environmental impact to a larger extent than suggested by Pelletier and Tyedmers (5). Although addressing excessive levels of consumption will help reduce environmental impact, there is a vast mitigation potential on the production side. We argue that addressing environmental impacts of livestock on the production side may also carry important benefits for socially and economically disadvantaged livestock producers in developing countries.