Global and regional drivers of power plant CO2 emissions over the last three decades

The past three decades have witnessed the dramatic expansion of global biomass- and fossil fuel-fired power plants, but the tremendously diverse power infrastructure shapes different spatial and temporal CO2 emission characteristics. Here, by combining Global Power plant Emissions Database (GPED v1.1) constructed in this study and the previously developed China coal-fired power Plant Emissions Database (CPED), we analyzed multi-scale changes and underlying drivers from the globe to the unit in generating capacities, age structure, and CO2 emissions over the past 30 yr. Our estimates show global CO2 emissions from the power sector increased from 7.5 Gt in 1990 to 13.9 Gt in 2019, and the growth of power demand meeting by large and young units mainly drives this increase for all stages. However, regional drivers were broadly different from those affecting global trends. For example, the critical roles of thermal efficiency improvement (accounting for 20% of the decrease in CO2 emissions) by eliminating small and low-efficient coal-fired units and fossil fuel mix (61%) by developing natural-gas- and oil-fired units were identified in preventing CO2 emission increases in the developed regions. By contrast, the decrease of fossil fuel share by speeding up the expansion of renewable power gradually demonstrates its importance in curbing emissions in the most of regions, especially including the developing economies (i.e., China and India) after 2010. Our multi-scale results of 30 yr emission variations indicate the structure optimization and transformations of power plants is paramount importance to further curb or reduce CO2 emissions from the power sector.