To limit the global warming to 1.5 °C above pre-industrial levels, beyond which the most dangerous impacts of climate change will be felt, achieving carbon neutrality by the mid-21st century is essential. In addition to the climate policies, regional clean air actions are also intended for the reductions in fossil fuel emissions, including the short-lived emissions of aerosols and precursors. In the context of pursuing carbon neutrality, aerosol reductions related to air pollution control policies are very likely to have a great impact on the climate, adding to the impact of reducing CO2 emissions. Here, the global and regional impacts of changing aerosols following a carbon neutrality pathway on climate are assessed using the Community Earth System Model version 1 (CESM1). We find that the aerosol reductions significantly affect climate in the future, which far outweigh those of GHGs under carbon neutrality. Thus, substantial reductions in GHGs are necessary to reach the climate target and mitigate the harmful effects of aerosol reductions on climate.