A Multidimensional Assessment of Ecosystem Services: From Grey to Green Infrastructure

The notion of Ecosystem Services (ESs) is constantly increasing in interest given their provision of multidimensional values (environmental, social, economic, etc.). Nowadays ESs are at the center of green cities policies tackling the challenges of sustainability. More than 55% of the population is already living in urban areas, and this number is still rising. Within this context, challenges for sustainable development considering a circular economy perspective will be more concentrated in cities and in particular urban green spaces where strategies could be more effective for achieving sustainable urban development goals, such as improving public health, preserving biodiversity, reinforcing social cohesion, supporting the economy, providing opportunities for recreation, and helping in adapting to climate change. More specifically, the role of urban green spaces is testified by many green infrastructures policies proposed by different cities around the world. Rooftops, abandoned infrastructures and downgraded areas are some of the places that can be reused for creating new natural and green spaces within cities. Given these premises, the present paper aims to investigate the role of green areas in urban context in improving the overall quality of the space and in providing multidimensional benefits. The innovation of the present paper regards the integration of cost-based and value-based methods for the assessment of ESs. Starting from a real case study located in the city of Milan, the article illustrates the potential of combining the valuation of biophysical and economic values.