Scale is an emergent theme in current scientific and policy debates on low-carbon urban transformations. Yet notions of scale employed in such contexts are typically based on linear and hierarchical ontologies, and miss out on the long-standing development of more nuanced conceptions of scale within Human Geography. This paper aims to advance a relational understanding of scale in the analysis and evaluation of low-carbon urban initiatives (LCUIs). We wish to lay the path towards an innately geographical conceptualisation of low-carbon urban transformations more generally, in which cities are not seen as rigid and passive physical containers for decarbonisation initiatives, but rather as key nodes within vibrant socio-technical networks operating across multiple material sites. Using a case study of the transnational and translocal REACH (Reduce Energy use And Change Habits) project funded by the European Union as illustration, we argue that low-carbon urban transformations are immanently constituted of three sets of relational processes across scale, involving (1) politicisation, (2) enrolment and (3) the hybridisation of human and material agencies.
Keywords: decarbonisation; hybrid geographies; networks; scale; urban transformations.