Human activities have already reached the edge of the planetary boundaries and even over-crossed them in some cases. Globally, agricultural and in particular livestock systems are an important source of greenhouse gas emissions and are among the leading causes of biodiversity loss and water pollution. Besides the provision of protein-rich foodstuffs (using grasslands -ruminants- or food waste -monogastrics-) livestock husbandry used to substantially contribute to soil fertility (via manure excretion), capital storage and labor substitution. Modern livestock husbandry, however, lost its original ecological and socio-cultural role in a functioning farming system by unilaterally focusing on milk, meat and egg production. On one hand, modern intensive livestock systems are highly efficient in terms of per-head productivity of meat, milk and eggs. On the other hand, the intensification of livestock systems during the past few decades has resulted in a number of downsides. Through the substitution of grassland with feed concentrates, the pressure on arable land increased and led to severe nutrient imbalances at farm, country and regional levels. Furthermore, the intensification of livestock production resulted in a higher incidence of livestock diseases and a decreased longevity of animals.
Despite these problematic developments economic conditions still favor intensive livestock systems. The projected increase of the world population and demand for livestock products, coupled with a rapidly diminishing natural resource base, call for an urgent reduction of the ecological footprint of livestock production.
There are various models on global agricultural land use and livestock production addressing food security, greenhouse gas emissions and other challenging aspects of the livestock sector. However, models analyzing the impacts of a global conversion of animal husbandry to low-input production systems (such as organic agriculture) on food availability and main global environmental challenges are lacking. In view of the increasing resource scarcity feasible alternatives in case of a shock scenario such as highly expensive or unavailable fossil fuel must be identified. More importantly, there is an urgent need to model the technical and economic feasibility of alternative food supply scenarios in a comprehensive and interlinked way. To this end, the potential impacts of a global conversion of livestock systems to low-input and organic systems on food security, climate change, biodiversity and on the use of natural resources will be computed and analyzed within this project.