Comprehensive Impact of Changing Siberian Wildfire Severities on Air Quality, Climate, and Economy: MIROC5 Global Climate Model’s Sensitivity Assessments

Wildfires emit atmospheric aerosols, affecting climate and air quality. Siberia is a known source region of wildfires. However, comprehensive knowledge regarding the impact associated with particulate matter pollution due to Siberian wildfires on climate and air quality and their effects on mortality and the economy under present and near-future warmer atmospheric conditions remains poor. Thus, we performed model sensitivity experiments (atmospheric model and coupled atmosphere-ocean model settings) simulating the effects of changing Siberian wildfire emissions under the present and near-future climate conditions, using the Model for Interdisciplinary Research on Climate version 5 (MIROC5). Increased Siberian wildfire smoke likely caused a cooling effect in broad areas of the Northern Hemisphere and worsened the air quality near the source and in the downwind region (i.e., East Asia). The more Siberian wildfires occur, the more air pollution is present in those regions, which likely increases mortality and welfare losses there. However, the total impact of changing temperature on the gross domestic product under present and near-future climate conditions is ambiguous. Our comprehensive results on the air quality changes due to Siberian wildfires under present and near-future climate conditions suggest that increased efforts to limit the aerosol impact of Siberian wildfires are crucial to prevent possible excess mortality and economic losses.