Impacts of reductions in anthropogenic aerosols and greenhouse gases toward carbon neutrality on dust pollution over the Northern Hemisphere dust belt

Abstract

To mitigate future global warming, many countries have implemented rigorous climate policies for carbon neutrality. Given some shared emission sources with greenhouse gases (GHGs), aerosol particles and their precursor emissions are expected to be reduced as the consequences of global efforts in climate mitigation and environmental improvement, potentially inducing complex climate feedbacks. However, a clear understanding of the individual effects of anthropogenic aerosols and GHGs on natural dust concentrations has not yet emerged, especially in the carbon neutral scenario. Here, we assess the large-scale impacts of reductions in anthropogenic GHGs and aerosol under a carbon neutral scenario in 2060 on natural dust emissions and concentrations over the low- to mid-latitudes in the Northern Hemisphere using the fully coupled Community Earth System Model. Our findings demonstrate a decline in atmospheric dust loading toward carbon neutrality (SSP1-1.9) relative to the high fossil fuel scenario (SSP5-8.5). Mechanistic analysis reveals counteracting modulation mechanisms: (i) reductions in aerosols amplify surface downwelling shortwave radiation, convection and wind speed, thereby promoting dust emissions by 6 %–12 % and concentrations by 4 %–20 % over North Africa, the Central Asia Desert and East Asia; (ii) GHGs reductions diminish the land-ocean thermal contrast and wind speed, suppressing dust emissions by 6 %–15 % and concentrations by 8 %–20 % mainly over the Central Asia Desert and North Africa. The latter drives the future dust responses. These results highlight that carbon neutral strategies not only achieve climate mitigation goals and air quality improvements, but also generate synergistic benefits through dust pollution suppression.