District heating is pivotal in urban decarbonization. As cities strive for climate neutrality, understanding emissions across the district heating supply chain is essential. Yet most studies focus on heat generation and fuel supply, while impacts of distribution infrastructure receive far less attention. This study closes that gap by delivering the first system-wide, bottom-up carbon footprint assessment of a metropolitan district heating network using real operational data from Berlin. Results show fuel combustion accounts for about 87% of total emissions, plant construction for 2%, and the distribution network for roughly 11%. Around 70% of network-related emissions stem from civil engineering activities such as excavation and backfilling. When comparing plastic casing pipes and ducted steel pipes, distinct embodied emission profiles emerge. However, civil engineering impacts remain the dominant factor. In addition, road restoration proves critical, as asphalt reinstatement generates nearly twice the emissions of natural stone pavement. Building on this, a scenario analysis indicates that bundling house-connection works can cut emissions by 12.8% by avoiding repeated excavation and transport processes. Looking ahead, as heat generation becomes increasingly decarbonized, the relative importance of infrastructure emissions will rise, making low-carbon construction and planning strategies indispensable. This approach calls for integrating carbon-footprint accounting into heating plans and regulations, prioritizing low-emission materials, and coordinating construction processes. The study offers a system-wide evidence base to help policymakers and utilities design infrastructure strategies aligned with climate-neutral district heating. • Infrastructure construction contribute up to 71% of emissions in the district heating network. • Network construction accounts for 11.2% of CO 2 emissions in the supply chain. • Using asphalt for pipe installation doubles CO 2 emissions compared to using natural stone. • Bundled house connections reduce emissions by 12.8%. • First systematic CO 2 analysis of Berlin’s district heating infrastructure.

• Innovative coupling between T-LCA, crop modeling and experimental design • The environmental performance of scenarios is assessed in a climate change context • This framework allows exploring various scenarios and services of cultivated area • Irrigation increase and stabilize the environmental performance of irrigated areas • This paper promotes coupling complex models with T-LCA and experimental design

Mycelium from basidiomycetes is gaining attention as a promising alternative protein source to address the rising global demand for sustainable proteins. This study presents a prospective life cycle assessment (LCA) of a novel food application based on Flammulina velutipes (FVE) mycelium produced via submerged fermentation using potato pulp as a substrate – a side stream from the food industry. In addition to a pilot-scale base case, three future scenarios for 2030 and 2050 (best-case, predictive, worst-case) were developed based on primary process data, expert estimates of efficiency improvements, and projected future energy mixes. Results show that, in the best-case scenario, the climate change impacts could be reduced by up to 95% by 2050 compared to the base case, primarily through process optimization and a decarbonized energy supply. Uncertainty analysis confirmed the projected reduction in climate change impacts across future scenarios and identified agitation efficiency as the key improvement priority for 2030, while thermal energy efficiency becomes critical by 2050. Through the application of a structured prospective LCA to an emerging mycelium-based food production, this study first identifies the key prospective elements and uncertainties that need to be considered. The results underscore the potential of mycelium as a sustainable protein source and emphasize the importance of early-stage process optimization and alignment with renewable energy supply to fully realize its environmental benefits.