• Energy Research
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Abstract Sustainable resource use calls for substantial changes to existing infrastructures, which lock societies into current resource use patterns. Urban mobility is a case in point: existing material stocks of infrastructure and vehicles require large amounts of materials and energy for maintenance and operation in order to provide mobility services, thereby causing considerable emissions. Understanding the stock-flow-service nexus of urban mobility is crucial for achieving progress towards absolute reductions of resource use and emissions. In this article, we investigate personal mobility in an urban context - Vienna. We use stock-driven material and energy flow analysis to quantify mobility stocks and flows for four different modes of mobility: pedestrian, bicycle, public transport and motorized individual traffic (MIT). We quantify material flows for maintenance, expansion, as well as primary energy use and emissions linked to personal mobility within city territory and compare a number of stock-flow-service indicators. Public transport was found to deliver most mobility services (38%), when services were measured as trips. Pedestrian mobility showed the lowest stock intensity of services while using less energy and generating lower emissions per service than any other mobility mode. Trips crossing the city border showed high shares of motorized individual traffic (62–63%). Traffic surfaces dominated material requirements of mobility and are mainly (78%) used by MIT. We conclude that considering stock-flow-service relations can support prioritizing future urban mobility planning, highlight the importance of infrastructure-related measures in doing so and the need for better monitoring especially of mobility service indicators.

Abstract As long as economic growth is a major political goal, decoupling growth from resource use and emissions is a prerequisite for a sustainable net-zero emissions future. However, empirical evidence for absolute decoupling, i.e. decreasing resource use and emissions at the required scale despite continued economic growth, is scarce and scattered across different research streams. In this two-part systematic review, we assess how and to what extent decoupling has been observed and what can be learnt for addressing the sustainability and climate crisis. Based on a transparent approach, we systematically identify and screen more than 11 500 scientific papers, eventually analyzing full texts of 835 empirical studies on the relationship between economic growth (GDP), resource use (materials and energy) and greenhouse gas emissions. Part I of the review examines how decoupling has been investigated across three research streams: energy, materials and energy, and emissions. Part II synthesizes the empirical evidence and policy implications (Haberl et al 2020 Environ. Res. Lett. 15 065003). In part I, we examine the topical, temporal and geographical scopes, methods of analysis, institutional networks and prevalent conceptual angles. We find that in this rapidly growing literature, the vast majority of studies—decomposition, ‘causality’ and Environmental Kuznets Curve analysis—approach the topic from a statistical-econometric point of view, while hardly acknowledging thermodynamic principles on the role of energy and materials for socio-economic activities. A potentially fundamental incompatibility between economic growth and systemic societal changes to address the climate crisis is rarely considered. We conclude that the existing wealth of empirical evidence merits braver conceptual advances than we have seen thus far. Future work should focus on comprehensive multi-indicator long-term analyses, conceptually grounded on the fundamental biophysical basis of socio-economic activities, incorporating the role of global supply chains as well as the wider societal role and preconditions of economic growth.