UK net-zero policy design – from optimisation to robustness.

The need to deal with the deep uncertainty and system complexity associated to Net-Zero pathways, especially those relying on emergent greenhouse gas removal (GGR) technologies, has resulted in a growing body of literature on alternative decision-support approaches. Exploratory modelling, and specifically Robust Decision Making (RDM), are potential approaches capable of addressing these challenges: by exploring a wide range of conceivable futures, they explicitly embrace deep uncertainties while seeking to reduce system vulnerabilities. However, though RDM methods have been well documented, there is little insight as to how such approach might be integrated into Net-Zero policy design processes. By means of a workshop (n=17) and interviews (n=13) with the UK climate policy and energy modelling communities, this contribution provides insights into the role and potential of RDM in explicitly dealing with the deep uncertainties that pervade in the establishment of a 60–100 MtCO 2 UK GGR sector within three decades. The consultation process revealed that there is an appetite from the decision-making and analytical communities in integrating exploratory modelling concepts into UK policy design processes. It is recommended that to bridge the gap between theoretical RDM constructs and their broader adoption, the analytical process should include a broader set of disciplines and expertise. Specifically for the modelling community, this work suggests that in-use computational models should be adapted, rather than new tools developed. Key challenges also arise from the time and resources required, suggesting small scale place-based pilots could promote the acceptability and foster the adoption of the RDM methodology. • Exploratory approaches, specifically Robust Decision Making (RDM), could tackle deep uncertainty in UK Net Zero pathways. • RDM's participatory scoping stage could address the multitude of cross-cutting issues prevalent in Net Zero systems. • The breadth and depth in the scope of Net Zero are considered major obstacles to the adoption of exploratory approaches. • Addressing this challenge requires involving a wider set of disciplines and expertise in energy system modelling. • Small scale place-based pilots could foster capacity development for the adoption of the RDM methodology. [ABSTRACT FROM AUTHOR]