Contribution of Ecosystem Services to Air Quality and Climate Change Mitigation Policies: The Case of Urban Forests in Barcelona, Spain

TLDR

Urban forests provide ecosystem services that improve city quality of life, yet these services are rarely incorporated into environmental policy targets. The study quantifies urban forest regulating services and assesses their contribution to Barcelona’s air quality and climate change mitigation policy targets. The authors use the i‑Tree Eco model to quantify biophysical and monetary values of air purification, global climate regulation, and biogenic air pollution disservices. The study finds that while urban forests substantially reduce pollution in absolute terms, their impact is modest relative to city‑wide pollution and GHG levels, and effective mitigation requires coordination with broader territorial policies.

Abstract

Mounting research highlights the contribution of ecosystem services provided by urban forests to quality of life in cities, yet these services are rarely explicitly considered in environmental policy targets. We quantify regulating services provided by urban forests and evaluate their contribution to comply with policy targets of air quality and climate change mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in biophysical and monetary terms the ecosystem services "air purification," "global climate regulation," and the ecosystem disservice "air pollution" associated with biogenic emissions. Our results show that the contribution of urban forests regulating services to abate pollution is substantial in absolute terms, yet modest when compared to overall city levels of air pollution and GHG emissions. We conclude that in order to be effective, green infrastructure-based efforts to offset urban pollution at the municipal level have to be coordinated with territorial policies at broader spatial scales.