Abstract
Global engineering projects are major carbon emitters with high heterogeneity, but traditional assessment methods (e.g., LCA, IPCC) lack precision, efficiency, and adaptability to dynamic construction. This study proposes a Carbon Footprint-aware Graph Neural Network (CF-GNN) for lifecycle carbon assessment. Its core innovations include: (1) a dynamic heterogeneous graph (entity/attribute nodes) updated via 15-day cycles and milestone triggers; (2) a carbon-sensitive dual attention mechanism prioritizing high-emission nodes/edges; (3) a third-order message passing framework capturing multi-hop carbon flows (up to 5 nodes). Validated on 3.86 million time-series data from 16 projects (residential, bridge, factory, etc.) against 8 baselines (LCA, GAT, TGAT, etc.), results show: CF-GNN achieves an average MAPE of 7.2% (38.9% lower than GAT, 55.8% lower than LCA), with bridge project RMSE at 218 tCO₂ (59.4% lower than LCA). It has 2.0±0.1s inference latency for 1000 nodes and 52±3.1min end-to-end assessment—3375-fold less manual effort than LCA (6 months/bridge). Key node identification matches experts (0.87 Kendall coefficient), with CV<5% (high stability) and 94.2±1.5% coverage for 95% prediction intervals. CF-GNN enables precise, efficient dynamic assessment, supporting low-carbon design/optimization and advancing "dual carbon" goals in construction, transportation, and energy.