Studies that focus on different urban governance structures, especially unitary states and semi-authoritarian regimes, are still lacking in the urban climate governance literature. This research aims to explain how climate change is governed under a unitary state structure, particularly focusing on how urban climate governance incorporates higher-level government policy and external stakeholders to set a climate agenda and actions. Four main themes are framed from the urban climate governance literature, including agenda setting, the divergence between the existing policies and urban climate agendas, policy entrepreneurs’ roles, and civil society organizations. By focusing on the four themes, we aim to understand how climate change is governed in Istanbul, the biggest and the richest city of Turkey, under a unitary system of government. Based on semi-structured interviews, field notes based on participant-observations, and review of existing official documents, we find that swings in political leadership, the divergence between the existing laws and newly adopted urban climate agendas, and conflicting priorities between policy entrepreneurs generate barriers to long-run and tangible climate change actions in Istanbul. Nevertheless, we argue there is an opportunity space for local governments to co-create new governance mechanisms, as the national government does not have the capacity to lead climate change action, nor is there a political will and focus at the highest levels of government to engage deeply in this policy space.

For millennia, cities have invested in inter- and intra-regional infrastructure to transfer water from neighboring sources. This study analyzed how climate change can affect the balance of water supply and demand in the megacity of Istanbul, Turkey over the next 100 years. The Water Evaluation and Planning (WEAP) method was used to examine three long-term scenarios for water availability based on differences in water supply: 1) a continuation of current supply sources; 2) expansion of water resources based on construction of additional water infrastructure; and 3) reduction in water resources to rely on local resources only. Our findings show that extending dependence on inter-regional water supplies is not only likely to increase Istanbul’s own water insecurity, but may also affect the human populations, biodiversity and economies of neighboring cities, representing an unsustainable solution that can only exacerbate regional water insecurity in the long run.

Systemic sustainability transitions are manifested as the needed scope to meet sustainability challenges at the local and global scales. While sustainability transitions are ubiquitous, each transition is nested in a specific spatial context. Especially, due to accelerating urbanization, cities are increasingly important agents, but they are also understudied geographical loci of change. Urban transitions are interesting because they operate at both the national and global scales, concentrating people, wealth, and resources. They have both regime and niche elements, as they act as an incubation space for novel experiments, ideas, and alternative social movements. Thus, this paper aims to improve understanding of the geographical context and spatial scales from a multilevel perspective and develop a framework for analytic comparison. Furthermore, the paper draws insights from two empirical cases, namely the cities of Helsinki and Istanbul. Consequently, opportunities and challenges for instigating context-specific sustainability transitions can be identified.