In this study, the impact of solar and wind power generation on greenhouse gas (GHG) emissions was analyzed using panel data from 16 metropolitan local governments, excluding Sejong City, between 2010 and 2021. The analysis was conducted using a pooled mean group estimation model. The results indicated that a 1% increase in gross regional domestic product (GRDP) led to a 4.256% increase in GHG emissions; however, once GRDP surpassed a certain threshold, the trend reversed, with emissions decreasing by 0.585%. A 1% increase in energy consumption caused a 0.328% rise in GHG emissions. An increase of 1% in solar and wind power generation resulted in a 0.041% and 0.119% decrease in GHG emissions, respectively. This suggests that solar power generation would need to be increased by 24.39% to reduce GHG emissions by 1%, whereas wind power would need to be increased by 8.4%. In essence, increasing wind power demonstrates an approximate 2.9-fold greater effectiveness in reducing GHG emissions by 1% compared to increasing solar power.