he’s spent years grappling with barriers to retrofit existing cities.

To put any of these ideas into practice requires the involvement of diverse actors across scales from the local to global (Ostrom et al., 1999). While cross-scale translation is necessary to inform decisions by such actors at sub-global scales, translation is complicated by the spatial heterogeneity of pressures and impacts (Biermann & Kim, 2020) and the value-laden (Biermann & Kalfagianni, 2020; Häyhä et al., 2016) and potentially iterative (Pickering & Persson, 2020) judgments involved in the allocation of these targets.