Global and Regional Drivers of Power Plant CO2 Emissions Over the Last Three Decades Revealed From Unit‐Based Database.

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. Plain Language Summary: The power sector is the top CO2 emitter and accounts for 37% of global anthropogenic emissions, which has great significance for climate change. Our combined database shows that the capacity of global fossil‐fuel‐ and biomass‐fired power plants experienced a substantial increase, mainly driven by the growing demand of power generation during the past three decades. In contrast to 133.3% increase of power capacity, global CO2 emissions of power plants increased by 85.3% during the period 1990–2019, and the disproportionately low increase of emissions benefited from the upgrade of coal‐fired power units and the large‐scale expansion of non‐coal‐fired ones with low/zero carbon intensity. Specifically, global power plant fleet turnover improved the power generation efficiency and optimized the fuel mix by constructing large and technologically advanced power units, slowing the growth rate of global CO2 emissions in 1990–2019. Moreover, changes in the critical role of fossil fuel power were associated with regional economic growth, environmental policy and technological advances, indicating that the expansion of non‐fossil‐fuels will likely represent an increasing factor in driving future CO2 emission reductions from the power sector. Key Points: Global CO2 emissions from the power sector increased from 7.5 Gt in 1990 to 13.9 Gt in 2019, mainly driven by the growth of demandThe efficiency improvements and the non‐coal power development carry positive effects on decreasing CO2 emissions in the developed regionsThe power shift from fossil fuels to non‐fossil fuels plays an increasingly critical role on curbing CO2 emissions in developing regions [ABSTRACT FROM AUTHOR]