Quantifying Embodied Carbon in South Sudan's Road Reconstruction: A Life Cycle Assessment for the 2021–2026 Period

{ "background": "Road infrastructure reconstruction in post-conflict regions is a critical development activity, yet its associated embodied carbon emissions remain largely unquantified, particularly in fragile states with nascent environmental governance.", "purpose and objectives": "This study aims to quantify the cradle-to-site embodied carbon of a major national road reconstruction programme, identifying the most emission-intensive life cycle stages and materials to inform low-carbon construction strategies.", "methodology": "A process-based life cycle assessment (LCA) was conducted, modelling material production, transport, and construction phases. Primary data were collected from project bills of quantities and logistics records. Emissions were calculated using $E = \\sum{i} (Mi \\times EFi) + \\sum{j} (T{j} \\times D{j} \\times EF{j})$, where $Mi$ is material mass, $EFi$ is emission factor, $Tj$ is transport type, $Dj$ is distance, and $EFj$ is transport emission factor. Uncertainty was propagated using Monte Carlo simulation.", "findings": "Material production, dominated by cement and steel, accounted for 78% of total embodied carbon (95% CI: 74–82%). The transport of construction materials over long international supply chains contributed a further 19%. Sensitivity analysis indicated that sourcing cement regionally could reduce total emissions by an estimated 14%.", "conclusion": "The embodied carbon of road reconstruction is substantial and heavily concentrated in the material production phase. Current reliance on imported materials significantly inflates the carbon footprint.", "recommendations": "Policymakers and engineers should prioritise low-carbon material specifications and develop regional material supply chains. Environmental product declarations should be mandated in procurement.", "key words": "embodied carbon, life cycle assessment, road infrastructure, sustainable construction, post-conflict development", "contribution statement": "This paper provides the first quantitative LCA of embodied carbon for a large-scale infrastructure programme in the country, establishing a benchmark