Forest cover as a green buffer against urbanization pressures: evidence from the EU

Purpose This study tests the Green Buffer Hypothesis (GBH) for 25 European Union member countries from 1990 to 2023. It asks whether forest cover, as a component of green infrastructure and natural capital, mitigates the environmental pressures associated with urban sprawl. In addition, the study examines whether income–environment dynamics follow an Environmental Kuznets Curve (EKC) pattern for different pollutants, focusing on PM2.5 exposure and CO2 emissions. Design/methodology/approach We employ panel econometric methods suited to multi-country data with cross-sectional dependence and heterogeneous slope parameters. To capture gradual structural change over time, we incorporate a Fourier expansion in the empirical specification. The GBH is tested by evaluating whether higher forest cover reduces the pollution intensity linked to urbanization for two outcomes: PM2.5 exposure and CO2 emissions. We also test for EKC-type nonlinearities to assess whether income effects differ across pollutants. Findings Results consistently support the Green Buffer Hypothesis for both PM2.5 exposure and CO2 emissions. Greater forest cover is associated with smaller environmental costs of urban expansion, and within countries over time, increases in forest cover correspond to lower pollution intensity. EKC evidence is pollutant-specific: an EKC pattern is confirmed for CO2 emissions, while no comparable evidence is found for PM2.5 exposure. This indicates that income–environment relationships do not follow a single common trajectory across pollutants. Practical implications The findings imply that maintaining and expanding forest cover can reduce pollution pressures associated with urban growth. Policymakers should integrate forest conservation, afforestation and urban–peri-urban green belts into spatial planning, alongside conventional urban infrastructure investments. Forest-based carbon management strategies can be aligned with broader mitigation objectives by treating forest cover not only as a carbon sink but also as a complementary tool for lowering the emissions intensity of development. Monitoring should prioritize where urbanization is fastest and forest buffers are weakest. Originality/value The study contributes by providing a long-run, multi-country test of the Green Buffer Hypothesis in the EU (1990–2023) for both PM2.5 exposure and CO2 emissions, using panel methods that explicitly handle cross-sectional dependence and parameter heterogeneity. The Fourier expansion allows the model to track slow moving changes over the study period without forcing abrupt breaks. Taken together, the Green Buffer Hypothesis and Environmental Kuznets Curve evidence shows that the income environment story is not the same for every pollutant, and it reinforces the role of forests as a practical green buffer in urbanizing economies.