Cities are increasingly seen as having an important role in tackling societal challenges related to climate change, while open innovation is increasingly accepted as a new way of working for governments. In the current work, we explore the role of open innovation to tackle global challenges on a city level. In the context of the city of Rotterdam and its vision on sustainability and liveability, seven collaborative initiatives are introduced. These initiatives aim to address both sustainability and liveability goals. Our research shows that in order to have these initiatives contribute to the overall municipal goal on sustainability and liveability, the municipality needs to take different roles. Whereas traditional open innovation literature usually distinguishes three main types of open innovation, namely outside-in, inside-out, and coupled processes, the current study shows that open innovation for sustainability in the city needs a much more fine-grained and elaborate perspective; a multi-level open innovation model that allows for different co-creative partnerships joining forces in sustainability challenges. It can be concluded that governments have a key role in infrastructuring these co-creative partnerships.

Over the past years, a growing number of local initiatives are generating solutions for societal challenges in their cities. However, the scale and complexity of these challenges force urban innovators to constantly adapt and learn, having to acquire new capabilities that will help them advance towards systemic change. In the current work, we take the premise that these urban innovators need to be able to utilise the urban context as a learning ecosystem in order to push their interventions beyond the boundaries of small innovative niches. In keeping with Schön's reflective practice, we envisage reflection as a core competence for these urban change makers to grow and present a reflective process supporting urban innovators in framing their professional learning journey to succeed in their projects. A series of online sessions have been conducted to investigate how to scaffold a reflective process enabling innovators to better identify challenges in their projects and the corresponding capabilities they need to acquire. In the proposed paper, we present reflective activities as a tool supporting urban innovators in self-defining their learning journeys and elaborate on the insights gained. It can be concluded that the reflective process we developed was valuable to urban innovators in unveiling new learning needs for their projects, while further research is needed to more effectively translate these learnings into actionable steps to sustain innovators' self-development.