Aerosol radiative and climatic effects on ecosystem productivity and evapotranspiration

Aerosols affect ecosystem photosynthesis and evapotranspiration through the perturbations in Earth's energy balance and changes in climatic conditions. Aerosols enhance plant photosynthesis by increasing diffuse radiation, but meanwhile the reductions in direct radiation may dampen or even overweigh the diffuse fertilization effects, especially at the high loading of aerosols and cloud. Aerosol-induced cooling has positive (negative) impacts on photosynthesis at low (high) latitudes. The enhanced drought by aerosols may decrease both photosynthesis and evapotranspiration. On the global scale, the net effects of aerosols on ecosystems are limited due to the offset of radiative and climatic effects. Our review highlights the importance of understanding the interactions among aerosols, climate, and vegetation.