Earth and Atmospheric Sciences, Department of


Date of this Version



Published in Nature Geoscience 16 (September 2023), pp. 758–759.



Improving air quality by reducing atmospheric aerosols can bring valuable health benefits, but also generally leads to warming. Now, research suggests that in cleaner air the local cooling effect of planting trees may be stronger in middle and low latitude regions.

Forests provide a substantial sink for atmospheric carbon and therefore have great potential for contributing to climate change mitigation globally.1 Meanwhile, forests play an important role in local and regional climate through their effects on albedo, evapotranspiration, and surface roughness.2 The biogeophysical mechanisms driving forest-climate feedback depend strongly on the local background climate. But it remains unclear how the background level of aerosol in the atmosphere may affect the climate impacts of planting trees. This is an important question given the increasing efforts in many regions to reduce aerosol emissions and improve the quality of the air we breathe. Writing in Nature Geoscience Ge et al. explore the joint effects of tree planting and air quality control, and show that reducing atmospheric aerosol pollution could substantially influence how planting trees affects local climate.3