In this paper we examine two central concepts of urban metabolism ('system boundaries' and 'flows'), and explore how to approach them as a means to politicise urban metabolism research. We present empirical findings from two case studies of waste management, in Mexico City and Santiago de Chile, looking at: the materiality of waste flows, the actors involved in them, and how waste flows relate to issues of environmental justice. We argue that urban metabolism, as a methodology to understand urban sustainability, has the potential to produce knowledge to trigger urban transformations, and to analyse the social, political and environmental aspects of waste management in urban areas.

This article examines how national energy policies in Chile constitute urban energy landscapes characterized by environmental and spatial inequalities. The concept of urban energy landscapes is deployed to explain the spatial patterns resulting from energy governance and energy conflicts in the metropolitan area of Concepción, a metropolitan region of strategic importance in the configuration of national energy policy. These urban energy landscapes result from the constitution of 'sacrifice zones' that reflect an extractivist model of energy production. The combination of qualitative interviews and transect walks reveals different aspects of a dual arrangement of energy infrastructure and urbanization. The city's fragmented landscapes emerge from the coexistence of energy infrastructure and associated industries, with daily activities of communities that have little to do with these industries but live in their shadow. Conflicts in these urban energy landscapes are intense, with every inch of space contested by competing modes of 'being urban.' The urban energy landscape in Concepción is an expression of a clash of social and economic power with local priorities.Keywords: urban energy landscapes, industrial landscapes, sacrifice zones, energy conflicts, coal energy, Chile

El objetivo de esta investigación es presentar un análisis sobre la participación de actores sociales regionales en los debates actuales acerca del proceso descentralizador en Chile. Con base en la literatura académica se elaboró una metodología de análisis documental y cualitativo de un diario regional, para indagar sobre la relación entre dichos actores y la formación de agendas en la Región del Bío Bío. Aunque los resultados están limitados por la representatividad del estudio, indican la preponderancia de los actores estatales en los debates económicos y las reformas legales, y la ausencia de movimientos sociales. La contribución significativa de esta investigación es su potencial para enriquecer los estudios de evaluación del proceso descentralizador chileno, en medios de comunicación constructores de opinión pública, relacionados con quienes tienen poder para establecer la jerarquía de temas y actores, e incluso su omisión. Se concluye que existe un debate elitista sobre la descentralización y una agenda marcada por una dinámica centralista, lo que cuestiona la solidez local de dicho proceso.