Biodiversity conservation: The key is reducing meat consumption.

The consumption of animal-sourced food products by humans is one of the most powerful negative forces affecting the conservation of terrestrial ecosystems and biological diversity. Livestock production is the single largest driver of habitat loss, and both livestock and feedstock production are increasing in developing tropical countries where the majority of biological diversity resides. Bushmeat consumption in Africa and southeastern Asia, as well as the high growth-rate of per capita livestock consumption in China are of special concern. The projected land base required by 2050 to support livestock production in several megadiverse countries exceeds 30-50% of their current agricultural areas. Livestock production is also a leading cause of climate change, soil loss, water and nutrient pollution, and decreases of apex predators and wild herbivores, compounding pressures on ecosystems and biodiversity. It is possible to greatly reduce the impacts of animal product consumption by humans on natural ecosystems and biodiversity while meeting nutritional needs of people, including the projected 2-3 billion people to be added to human population. We suggest that impacts can be remediated through several solutions: (1) reducing demand for animal-based food products and increasing proportions of plant-based foods in diets, the latter ideally to a global average of 90% of food consumed; (2) replacing ecologically-inefficient ruminants (e.g. cattle, goats, sheep) and bushmeat with monogastrics (e.g. poultry, pigs), integrated aquaculture, and other more-efficient protein sources; and (3) reintegrating livestock production away from single-product, intensive, fossil-fuel based systems into diverse, coupled systems designed more closely around the structure and functions of ecosystems that conserve energy and nutrients. Such efforts would also impart positive impacts on human health through reduction of diseases of nutritional extravagance.