In cities worldwide, low-carbon urban initiatives (LCUIs) are realised by pioneers that prove that climate mitigation strategies can be integrated in urban development trajectories. Practitioners and scholars reflect on the need to scale-up such initiatives in order to accelerate the transition to low-carbon cities. Yet, limited conceptual clarity exists regarding the meaning of the concept of ‘scaling-up’ and the factors driving this process. This article aims to contribute to practice and theory on low-carbon urban development by presenting a taxonomy on the concept of scaling-up. Moreover, an explanatory framework is presented consisting of factors expected to contribute to the impact and scaling-up of LCUIs. Two case studies were conducted to illustrate the explanatory framework. The studies are illustrative but suggest that the explanatory framework allows for a systematic understanding of how the impact of former initiatives can be explained, and how their scaling-up can be promoted.

Food production and consumption related environmental challenges have come to the forefront of policy discourse in the past decade. This links primarily to concerns in terms of agriculture fueling climate change, but also in terms of long-term food security and availability for growing populations. A proposed solution to these pressures at the urban scale is Vertical Farming (VF), in the understanding of this article, a high-yield form of controlled environment agriculture, staked on multiple layers, which promises to produce leafy greens and vegetables within cities, with potential to reduce the resource intensity of urban food production and consumption. The particular contextual conditions required for VF to be sustainable have not as of yet been holistically assessed. Accordingly, by analyzing these contextual conditions in the Global North, this research assesses how VF can be up-scaled for the sake of sustainability – particularly climate mitigation – by viewing urban food systems through the Multi-Level Perspective. The article presents three findings in relation to the up-scaling potential of VF. Firstly, singular VF interventions in cities should have further functions integrated at the scale of the farm for the sake of viability. Secondly, VF interventions carry the most potential for climate mitigation if they are viewed through urban-level systemic food planning, which sheds light on the contextual conditions needed for VF to contribute to sustainability. Finally, the globalized dynamics of the neoliberal political economy, and in turn the localized effects for food systems, have implications for VF that need to be taken into consideration in framing up-scaling policy.

Strategies applied by urban policy makers in order to achieve sustainable city development may be in conflict with each other because it crosses many disciplines and policy areas. This research focusses on the dilemma between compact city and urban greenspace policies and their influence on actual land-use change in Amsterdam and Brussels. These cases are selected because of their similar urban growth yet diverse policy and governance contexts. We contend that comparing how urban policies try to address this dilemma can provide a deeper understanding of how policy strategies affect land-use change. The results show that densification indeed decreases the quantity (Amsterdam: −4.7% Brussels: −11.9%), average size (A: −3.1% B: −25.6%) and connectivity of urban greenspaces. Observed land-use changes seem disconnected from purported urban greenspace policies, whereas urban development plans seem to dominate changes in greenspace quantity and form.