Based　on　208　city-level　data　in　China,　this　paper　empirically　analyzes　the　impact　of　ESG　rating　on　carbon　emissions　through　the　SDM　spatial　metrology　model,　identifies　the　direct　and　indirect　consequences　and　spatial　spillover　effects　of　ESG　rating　on　carbon　emissions,　and　compares　the　regional　heterogeneity　and　city-size　heterogeneity　of　such　impacts.　This　paper　draws　three　conclusions:　(1)　Empirical　evidence　shows　that　the　ESG　rating　performance　of　enterprises　has　a　significant　inhibition　effect　on　carbon　dioxide　emissions.　Specifically,　when　the　ESG　rating　performance　increases　by　1%,　carbon　emissions　will　decrease　by　0.076;　among　other　control　variables,　the　effect　of　FDI　on　carbon　emission　reduction　is　that　when　ESG　score　performance　increases　by　1%,　carbon　emission　decreases　by　0.022.　(2)　In　the　decomposition　of　the　total　effects,　indirect　effects　and　direct　effects　have　the　same　impact　on　carbon　emissions,　and　the　total　effect　is　−0.393.　(3)　The　inhibition　effect　is　more　significant　in　the　Eastern　Region　and　in　megacities,　where　the　effect　of　−0.096　in　the　Eastern　Region　is　more　obvious　than　that　of　−0.078　at　the　national　level,　and　the　effect　of　carbon　reduction　in　megacities　is　significantly　greater　than　0.013　in　big　cities.　This　suggests　regional　heterogeneity　in　regards　to　the　role　of　ESG　ratings　in　reducing　CO2　emissions.　This　paper　reveals　the　specific　effects　and　internal　logic　of　the　impact　of　ESG　performance　on　CO2　emissions,　which　has　certain　implications　for　various　regions　to　further　promote　the　construction　of　an　ESG　system,　according　to　local　conditions,　and　to　encourage　enterprises　to　focus　on　emission　reduction　and　high-quality　development.　©　2024　by　the　authors.