Land cover changes reduce dust aerosol concentrations in Northern China (2000-2020)

Dust aerosols significantly impact climate, human health, and ecosystems, but how land cover changes (LCC) influence dust concentrations remains unclear. Here, we applied the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to assess the effects of LCC on dust aerosol concentrations from 2000 to 2020 in northern China. Based on land cover data derived from multi-source satellite remote sensing data, we conducted two simulation scenarios: one incorporating actual annual LCC and another assuming static land cover since 2000. Results revealed that approximately 293,300 km2 of land underwent conversion over the past 20 years. LCC generally resulted in an average annual reduction of 5.70 mu g kg-1 (micrograms per kilogram of dry air) in dust aerosol concentrations. The most significant reduction occurred in winter, averaging 8.90 mu g kg-1, followed by spring (8.06 mu g kg-1), autumn (5.27 mu g kg-1), and summer (1.06 mu g kg-1). Converting bare land to forestland was most effective in reducing dust concentrations, followed by conversions to grassland and built-up areas. Conversely, conversions to bare land increased dust aerosol concentrations, especially when forestland or cultivated land was transformed into bare land. These results emphasize the importance of targeted land use strategies to mitigate the adverse environmental and health effects of dust aerosols.