Driven by the dramatic increase in the power generation demand, young power units (<12 yr) continuously played essential roles in the contributions of global CO2 emissions (e.g., accounting for 39.9% of the total in 2019 compared with 38.5% of the total in 1990). However, the regional contributions in CO2 emissions from young power units have significantly changed over time.

Specially, China contributed the largest share (55.4%) of emissions from all young coal power units in 2019, followed by India (24.5%). Moreover, the evolution of emissions from young power units reflected regional disparities in fuel types owing to the differences in resource endowments.

CO2 emissions increased from 7.5 Gt in 1990 to 13.9 Gt in 2019 at a 2.2% growth rate per year, mainly dominated by the development of coal-fired power capacity in developing countries. In the most of developed regions, such as the United States and Europe, CO2 emissions from the power sector peaked before 2005.

Economies with higher CO2 emission intensities from power plants should enhance the energy efficiencies of fossil fuel-fired power plants by using more advanced electricity technologies and accelerate the transitions of emission-free renewable energy (e.g., solar and wind) in the context of carbon neutrality worldwide, aiming to develop low-carbon power systems in the future for climate change mitigation.