Take me to your leader: Using socio-technical energy transitions (STET) modelling to explore the role of actors in decarbonisation pathways

Quantitative modelling analysis in support of national and global decarbonisation pathways has never been more important to achieving global climate stabilisation in line with the Paris Agreement. However, established equilibrium and optimisation models tend to radically simplify their depiction of societal and political/institutional actors. This can make them difficult to use for implementing specific energy and climate policies in the near term and aligning these with long term targets. Most energy systems analysis continues to pair such techno-economic models with entirely qualitative narratives about future political and societal developments. The result is that these critical factors often fade into the background in subsequent discourse. In this paper, we utilise BLUE - a leading socio-technical energy transition (STET) model of the United Kingdom's (UK) energy system - to capture elements of the heterogeneity, consistency and co-evolution of societal and political drivers. We focus specifically on exploring government-led and societally-led energy transitions and investigating the differences in their decarbonisation pathways and end states. Our modelling exercise finds that it is not who leads per se that is the most critical, but rather the level of the initial effort and subsequent commitment from both leader and follower actors that appears to regulate the pace at which decarbonisation pathways unfold. However, systemic inertia in all cases means that the deepest decarbonisation targets continue to appear very difficult to achieve.