Cities as carbon sinks - biogenic carbon sequestration and storage

In an era marked by escalating environmental and social crises, transforming urban systems is necessary. Currently, urban environments epitomise the degenerative impacts of anthropogenic activities—net-consumers of natural resources and ecosystem functions, contributing little to their production. However, this need not be the case. By harnessing the internal transformative capacity of the built environment, urban systems can contribute to environmental benefits. This dissertation explores biogenic carbon sequestration and storage (CSS) in redefining the built environment's role in climate regulation, embodying restorative and regenerative urban planning principles. Integrating natural and built structures, the research explores enhancing carbon sink capacity within urban landscapes, offering mitigation and adaptation benefits in the face of rapid urbanisation and accelerating climate change. The research presents a case study of biogenic CSS capacity in the built environment. It employs theoretical and empirical approaches, broad literature reviews, and precise case studies to build the key findings and main argument. The research uses quantitative and qualitative perspectives, mixing them to increase the robustness and credibility of the presented causal argumentation. The ensuing results are reflected upon the identified theoretical and conceptual frameworks and used to draw connections across all the studied scopes, accounting for inherent limitations, uncertainties, and potential weak points in the adopted research approach. Through this comprehensive analysis, the dissertation concludes that significant capacity exists for biogenic CSS improvement in the built environment. Integrating natural and built components into the urban carbon pool by increasing green space and canopy cover, using biogenic materials, and mimicking natural ecosystems' structure and functions presents potential to match or exceed pre-development CSS rates. This requires considering intertwined causal drivers, suggesting that increasing the carbon sink capacity of the built environment is best achieved in tandem with broader urban sustainability transformation. However, contemporary planning and development strategies characterised by simple heuristics often fail to harness this potential. The findings propose that these strategies inadvertently compromise the ecological quality of the built environment by neglecting urban complexity and its functionalities. Thus, the dissertation argues for a fundamental shift in urban planning and development strategies—from singular, performance-targeted approaches to holistic, multicriteria perspectives that embrace urban systems' complexity. The thesis significantly contributes to advancing urban carbon accounting discourse, conceptualising cities as active producers of carbon sink capacity.