Cross-scale trade-off analysis for sustainable development: linking future demand for animal source foods and ecosystem services provision to the SDGs

Dietary transition towards higher consumption of animal source foods (ASF) associated with higher incomes across low and middle-income countries could have negative impacts on environmental systems and their potential in the long run to provide services necessary for achieving multiple Sustainable Development Goals (SDGs). In this article, we integrate economic, land use allocation, and biophysical models to investigate trade-offs between the five ecosystem services and their contributions to various SDGs associated with agricultural expansion to meet future demand for ASF, using Tanzania as a case study. Our results show that under the scenario of sustainable socio-economic development, between 2010 and 2030 in Tanzania, per capita income grows by 169% and the share of population at risk of hunger declines from 34.8% to 23%. These changes can be associated on a macro-level with positive contributions to achievement of SDG 1 (No Poverty) and SDG 2 (Zero Hunger). To satisfy feed demand for increased livestock production domestically, an increase by 21.4% of biomass production as compared to 2010 is needed. Analysis of alternative scenarios for meeting this new demand shows potential threats on a landscape level to achieving numerous SDGs and more generally to attaining sustainable food systems. Ecosystem-based contributions primarily decline to SDGs: SDG 3 (Health), SDG 6 (Clean Water), SDG 11 (Sustainable Cities), SDG 13 (Climate) and SDG 15 (Terrestrial Life). We find that higher crop productivity and redesign of agro-ecosystems to increase on-farm tree cover could significantly limit these losses. Alternatively, the growing demand for ASF could be satisfied with imports, which would allow for reducing the trade-offs locally. However, this would result in at least partially only displacing ecosystem service losses to the exporting countries.