PES Results in the Tropics Are Region-Specific and Not Universal

Payment for Ecosystem Services (PES) programs are widely advocated as scalable climate mitigation tools, yet their effectiveness varies dramatically across regions. This study analyzes forest carbon dynamics in 86 tropical countries from 1990 to 2020, revealing sharp regional divergence that single-country studies have not captured. PES programs in Africa show positive associations with forest carbon stocks, while those in Asia and the Americas exhibit weak or negative relationships. These contrasting outcomes reflect differences in governance quality, rent distribution structures, and enforcement capacity rather than inherent policy design. Where commodity extraction pressures, weak oversight, or unstable property rights dominate, PES fails to produce carbon gains. This finding challenges the assumption that PES effectiveness transfers uniformly across contexts. International climate policy has extrapolated success cases from Africa into global strategy without adequately addressing institutional prerequisites. Our results demonstrate that PES viability depends on institutional fit, not universal scalability, with direct implications for climate finance mechanisms.