Visualizing energy, material and emission flows to understand scale and connections in the physical global economy
摘要
The global physical economy—the system of material, energy and emission flows from extraction to final use—has not been tabulated and visualized, but such a visual can guide improved resource efficiency, inform limits on alternative energy scale up and coordinate system-wide emissions reductions. We develop a structure and conventions to integrate dispersed data to visualize the dominant (> 50Mt/yr) global material, energy and emission flows from extraction to end-use through a Sankey diagram. This provides a quantitative map to comprehend scale and connections for resources and sectors typically studied in isolation—making clear, for example, that the annual mass of CO2 emissions in 2019 were greater than all solid material produced globally. Fossil fuels are not only the primary source of emissions, but also constitute some of the largest mineral flows (> 15Gt/yr, greater than all metallic minerals combined). This structure can be used to explore the resource implications of scaling up low-carbon electricity generation and biomass feedstocks. The transition from fossil fuels to a solar and wind-dominant energy system can reduce the throughput of minerals and energy for the energy system. Demand for biomass may increase by 1.5-2X to 2050, requiring coordination to ensure its best use. The Sankey diagrams presented here provide a coherent understanding of the current physical flows underpinning economic activity and support collective visioning for using resources to provide final goods and services with greater efficacy.