This thesis proposes to evaluate the progression of negative trends in emissions and pathways and practical questions of scale-up through a combination of energy systems analysis and science communication. Firstly, it will quantify 'how transformed' the global energy system is, in terms of decarbonised power, transport, heat and industry. It will consider not just the direct carbon mitigation, as in most reports (i.e. TWh of generation from renewables; carbon emissions per passenger-km for transport); but also the 'enablers' of transformation, such as
the degree of power systems flexibility, density of electric vehicle charging points, cost gap between low-carbon and conventional heating. Secondly, it will create a transparent
methodology for translating the progress to date into the unit of 'wedges', so that national and global progress can be presented in a simple yet meaningful way to audiences beyond energy experts. Thirdly, it will apply the methodology to a selection of renowned scenarios for future decarbonisation; exploring the number and mix of wedges needed to help explore the level of consensus or dissent in views to decarbonise the global economy, and pinch-points where things are infeasible.