The First City Organizational LCA Case Study: Feasibility and Lessons Learned from Vienna

Cities are recognized as a major contributor to environmental pressures. Recently, organizational LCA (OLCA) has been found to align well with requirements for city-scale environmental decision support and a novel city-OLCA framework was introduced. City-OLCA combines two relevant aspects: It covers activities beyond public service provision (multi-stakeholder) and emissions beyond greenhouse gases (multi-impact). Its unique approach of acknowledging responsibility levels should help both city-managers and academia in performance tracking and to prioritize mitigation measures. The goal of this work is to test city-OLCA's feasibility in a first case study with real city data from Vienna. The feasibility was confirmed, and results for 12 impact categories were obtained. As an example, Vienna's global warming potential, ozone depletion potential, and marine eutrophication potential for 2016 were 14,686 kt CO2 eq., 6796 kg CFC-11 eq., and 310 t N eq., respectively. Our results indicate that current accounting practices may underestimate greenhouse gas emissions of the entire city by up to a factor of 3. This is mainly due to additional activities not covered by conventional standards (food and goods consumption). While the city itself only accounts for 25% of greenhouse gases, 75% are caused by activities beyond public service provision or beyond governmental responsibilities. Based on our results, we encourage city managers to include an organizational based LCA approach in defining reduction strategies. This will reveal environmental blind spots and avoids underestimating environmental burdens, which might lead to setting the wrong focus for mitigation.