Synergistic effects in urban industrial CO₂ and SO₂ reductions: Distribution dynamics and spatial insights from pearl river-west river cities

Amid rapid industrialization and urbanization, the Pearl River-West River Economic Belt (PRWREB) has resistered notable economic gains alongside intensifying environmental pressures. This paper examines the synergistic emissions reduction effects of CO₂ and SO₂ across eleven cities within the PRWREB. The results reveal that significant synergistic effects exist between the reduction of industrial CO₂ and SO₂ emissions in the PRWREB, with the majority of cities exhibiting synergistic emissions reduction indices within the range of −1 to 1. Additionally, the synergistic emissions reduction effects display a fluctuating trend, reflecting a low overall level of development and limited disparity between the eastern and western regions. Finally, spatial variations in the synergistic emissions reduction effects across cities are evident, with intra-regional variation emerging as the primary source of overall variation, followed by inter-regional variation, which exhibits the lowest hyper-variance density. The findings provide new insights into emissions reduction and air pollution management in the economic belt, thereby establishing a theoretical foundation for governments to design more effective policies that promote synergistic reductions.