Comparative Environmental Assessment of Construction Materials in Climate Action Projects

• The environmental impacts of climate action must be assessed in the planning phase. • The Life Cycle Impact Assessment is a suitable framework for assessing different projects. • Environmental impacts can be significantly reduced by choosing the right materials. Climate action projects increasingly depend on construction materials whose embodied impacts strongly influence sustainability performance, yet cross-comparison between different types of infrastructure remains limited. This study evaluates the material related environmental impacts of representative European climate interventions using a unified life cycle impact framework focused on production and delivery stages. A structured workflow was applied, including project selection, inventory extraction from public technical reports, material quantification, and impact modeling using Global Warming Potential (GWP), Ozone Depletion Potential (ODP), and Human Toxicity (HT). To allow a consistent comparison between heterogeneous interventions, results were normalized using category-specific functional units: floor area for buildings, surface area for parks, and length for flood defenses. Ten projects spanning building renovation, insulation upgrades, green infrastructure, and flood prevention systems were analyzed. The results show that environmental performance is governed primarily by material intensity rather than project size alone. Flood prevention infrastructure exhibits the highest absolute impacts due to heavy mineral material requirements, whereas green infrastructure projects demonstrate low normalized impact intensity relative to spatial scale. Renovation and insulation projects show wide variability depending on envelope material strategies, showing embodied exchanges that are not visible in total impact values. By integrating material inventories with category-based normalization, the framework transforms conventional material LCA into a comparative engineering tool capable of evaluating several climate actions on a common basis. This approach supports evidence-based material selection, exposes efficiency differences between intervention strategies, and advances the practical integration of embodied impact metrics into climate infrastructure planning.