Research on the potential of urban green-blue infrastructure in carbon reduction benefits

Urban green-blue infrastructures (GBIs) are increasingly gaining attention in the pursuit of carbon neutrality, particularly within residential areas. With this background, this study established an integrated quantitative framework to assess both direct and indirect carbon reduction benefits of urban GBIs, by leveraging Life Cycle Assessment approach to precisely calibrate the carbon sequestration benefits of three typical urban GBIs (green roofs, sunken green spaces, and rain gardens) under three different scenarios and building a carbon sequestration database that includes 36 local plant species in Shanghai. The research results indicate that GBIs have a reducing effect on carbon emissions in urban residential areas. If extrapolating the simulation results to the city scale, the preliminary estimation suggests that the construction of GBIs within residential areas in Shanghai can achieve a carbon sink of approximately 540.54 million tCO₂eq per year. This level of carbon sequestration is equivalent to 32% of Shanghai’s annual carbon emissions. It is evident that the construction of GBIs possesses significant potential in carbon reduction benefits and for achieving urban carbon neutrality strategies.