Synergistic yet divergent climate effects of wind and solar energy in China toward carbon neutrality

Abstract

Wind and solar energy help reduce greenhouse gas (GHG) emissions and contribute to changes in global atmospheric circulations by altering the underlying surface albedo. However, the displacement of fossil fuel combustion not only reduces CO2 but also decreases scattering aerosols and their precursor emissions, yielding competing climate effects from negative radiative forcing (RF, cooling) due to avoided CO2 emissions and positive RF (warming) from aerosol demasking. We show that the net RF due to CO2 and SO2 emission reduction from displaced coal-fired power underwent a warming-to-cooling reversal from 2010 to 2022, with the sum of RF_CO2 and RF_SO4 changing from 1.492 ± 0.158 (10−4 W m−2) in 2010 to −16.621 ± 1.780 (10−4 W m−2) in 2022. By 2060, under the coal-replacement counterfactual, the absence of wind and solar deployment would result in an additional radiative forcing of 0.239 ± 0.025 W m−2 from the power sector alone, an upper-bound estimate underscoring the direct climatic dividend of renewable energy expansion. We find that omitting wind and PV power development would not only delay carbon peaking by 15–25 years but also preclude the achievement of carbon neutrality. These results underscore the necessity of jointly assessing GHG and aerosol impacts to fully capture the climate trade-offs and co-benefits of the energy transition.