Stratospheric sulfate geoengineering could enhance the terrestrial photosynthesis rate

With an 8 Tg yr⁻¹ injection of SO₂ to produce a stratospheric aerosol cloud to balance anthropogenic radiative forcing from the Representative Concentration Pathway 6.0 (RCP6.0) scenario, we conducted climate model simulations with the Community Earth System Model – the Community Atmospheric Model 4 fully coupled to tropospheric and stratospheric chemistry (CAM4-chem).

During the geoengineering period, as compared to RCP6.0, land-averaged downward visible (300-700 nm) diffuse radiation increased 3.2 W m⁻² (11 %). The enhanced diffuse radiation combined with the cooling increased plant photosynthesis by 0.07 ± 0.02 µmol C m⁻²