Great Britain’s carbon emissions from electricity generation fell by two-thirds between 2012 and 2019, providing an important example for other nations. This rapid transition was driven by a complex interplay of policies and events: investment in renewable generation, closure of coal power stations, raising carbon prices and energy efficiency measures. Previous studies of the impact of these simultaneous individual measures miss their interactions with each other and with exogenous changes in fuel prices and the weather. Here we use Shapley values, a concept from cooperative game theory, to disentangle these and precisely attribute outcomes (CO2 saved, changes to electricity prices and fossil fuel consumption) to individual drivers. We find the effectiveness of each driver remained stable despite the transformation seen over the 7 years we study. The four main drivers each saved 19–29 MtCO2 per year in 2019, reinforcing the view that there is no ‘silver bullet’, and a multi-faceted approach to deep decarbonisation is essential.
The experience of grid operators and planners in the United States and around the world has shown that both decarbonization and power system resilience will require large-scale regional and inter-regional trans- mission expansion. In the United States, transmission planning, cost recovery, and siting are all subject to both state and federal jurisdiction. To meet the challenge of expanding transmission to implement decarbonization, the Federal Energy Regulation Commission (FERC) and the National Association of Regulatory Utility Commissioners (NARUC) recently announced the Joint Federal-State Task Force on Electric Transmission to focus on this issue.1 Resolving issues of siting and cost recovery for interstate electric transmission lines will encourage constructive state-federal cooperation. The task force and related regional and national coordination among the states, FERC, the Department of Energy (DOE), and federally regulated transmission providers will be critical to ensuring a resilient and clean power system.