The global biodiversity footprint of urban consumption: A spatially explicit assessment for the city of Vienna.

With ongoing global urbanization processes and consumption patterns increasingly recognized as key determinants of environmental change, a better understanding of the links between urban consumption and biodiversity loss is paramount. Here we quantify the global biodiversity footprint (BDF) of Vienna's (Austria) biomass consumption. We present a state-of-the-art product specific approach to (a) locate the production areas required for Vienna's consumption and map Vienna's BDF by (b) linking them with data taken from a previously published countryside Species-Area-Relationship (cSAR) model with a representation of land-use intensity. We found that food has the largest share in Vienna's BDF (58 %), followed by biomass for material applications (28 %) and bioenergy (13 %). The total BDF occurs predominantly within Austria and in its neighbouring countries, with ~20 % located outside Europe. Although the per capita biomass consumption in Vienna is above the global average, global and Viennese per capita BDFs are roughly equal, indicating that Vienna sources its products from high-yield regions with efficient production systems and comparatively low native species richness. We conclude that, among others, dietary changes offer a key leverage point for reducing the urban BDF, while expanding the use of biomass for material and energy use may increase the BDF and requires appropriate monitoring.