Mapping urban carbon : an integrated assessment of soil and vegetation carbon storage in Glasgow

Abstract

As cities around the world race toward carbon neutrality, much of the focus has been placed on visible green assets like urban trees, while the less visible, yet equally critical, role of soils remains overlooked. This thesis presents Glasgow’s first integrated assessment of carbon storage in both aboveground vegetation and belowground soils across its diverse urban land-use types. Using GIS-based land-cover mapping, canopy analysis, and depth-based modeling of soil organic carbon, the study offers a comprehensive carbon inventory that includes not just traditional areas like urban parks or forests, but also areas beneath roads, pavements, and buildings, surfaces traditionally ignored in urban carbon accounting.

The findings reveal that Glasgow stores approximately 2.81 million tonnes of carbon, with soils holding over 90% of that total. This equates to an average of 16.3 kg C/m² citywide. Yet carbon storage is far from evenly distributed. Overall, permeable lands stores nearly three times more carbon per area (≈22.4 kg) than areas with impervious surfaces (≈8.2 kg). These disparities highlight the central role of land cover in shaping urban carbon dynamics.

These results underscore the importance of looking beneath the surface when planning for urban climate resilience. Soils, long hidden under layers of asphalt or policy neglect, are revealed as Glasgow’s most powerful carbon reservoir. By revealing the significant contribution of often-overlooked areas such as soils beneath impervious surfaces, the study challenges traditional assumptions in urban carbon accounting. The resulting spatial carbon inventory provides a valuable tool for evidence-based decision-making and offers a replicable model for other cities aiming to better understand and manage their natural carbon resources.