Developing a spatially explicit, global material flow model to trace environmental impacts embodied in international trade
Stefan Giljum, Martin Bruckner, Stephan Lutter
Vienna University of Business and Economics, Austria
In the era of globalisation, supply chains of goods and products are increasingly international, thus disconnecting the location of production from final consumption. Consumption therefore has developed into a major, geographically distant driver of various local environmental and social impacts in countries producing raw materials. Methods to assess global supply chains from raw material extraction to final consumption have improved significantly over the past few years. The approach most widely applied for consumption-based (or footprint-type) assessments is multi-regional input-output (MRIO) analysis. However, despite recent improvements, existing MRIO databases have important limitations for the application to material flows and related footprints, as their spatial resolution is limited to the national level. Current MRIO models thus need to assume average environmental or social impacts per unit of product originating from a certain country and are unable to link specific supply chains to the actual geographical locations of production.
The new footprint model aims at overcoming existing shortcomings by developing a spatially explicit, global material flow model. This highly detailed global material flow model covering extraction, transportation, processing and final consumption, will allow robust assessments of material footprints and related environmental and social impacts. For the first time it will be possible to trace products consumed in European countries back to the precise geographical location where environmental or social impacts related to raw material extraction take place. This step of spatial specification will significantly improve the reliability and policy significance of footprint assessments. The spatially explicit material flow model can be applied to analyse all environmental issues related to raw material extraction with a spatial dimension, including natural habitat degradation, soil pollution, water scarcity, deforestation and biodiversity loss. Also social issues such as violent conflicts on mining projects can for the first time be assessed in the context of material footprints.