Multi-system dynamics and the speed of net-zero transitions: Identifying causal processes related to technologies, actors, and institutions

Reaching net-zero GHG emission targets will require transitions in all socio-technical systems, including elec-tricity, mobility, heating, and agri-food. While most research focuses on transitions in single systems, it is essential to also investigate multi-system interactions since innovations like electric vehicles, heat pumps, or circular economy initiatives will require interactions between multiple systems. Although extant research ac-knowledges this topic to some extent, it offers limited understandings of the causal processes underpinning multi -system interaction. Building on multi-system research in the sustainability transitions literature, the paper therefore aims to develop a first inventory of causal processes of multi-system interactions in net-zero transitions, focused on technological, actor, and institutional dimensions. To elaborate and substantiate this contribution, the paper applies a narrative review methodology to identify six causal processes based on integration of insights from relevant social science theories with a multi-system dynamics approach based on the Multi-level Perspective. We illustrate causal processes with examples from the net-zero transition and articulate their im-plications for the speed of change.