PNNL

Abstract

Anthropogenic dust (AD) emissions due to heavy building, road construction, and off-road vehicle use have been increasing in recent decades. Whether its perturbations on urban air pollution at the global scale become significant are still unclear. Based on observations, we found that a high urban AD optical depth is often accompanied by severe non-dust optical depth in the planetary boundary layer(PBL), both magnitudes even comparable. To investigate the causes, an AD emission inventory constrained by satellite retrievals is implemented in a global climate model. The results show that AD-induced surface radiative cooling of up to -10.0 W m-2 regionally leads to reduced PBL height, which deteriorates non-dust pollution, especially over India and northern China, in addition to the tremendous direct AD contribution to pollutants. The estimated global total premature mortality due to AD is 0.8 million deaths per year and is more severe in populous regions.