An integrated LCA‐emergy‐carbon framework for environmental performance assessment of coastal park ecological restoration

Coastal park landscape ecological restoration provides recreational services while generating significant environmental burdens during construction and maintenance. To scientifically evaluate the environmental performance of different restoration alternatives, this study developed an integrated life cycle assessment (LCA)–emergy–carbon performance assessment framework, in which carbon footprint accounting is operationalized as the climate change impact category within the life cycle assessment framework, while emergy analysis supplements the thermodynamic perspective on resource consumption that LCA does not directly address. The framework was applied to compare conventional hard engineering and ecological engineering restoration approaches at two small-scale coastal landscape park restoration sites, quantifying carbon emissions, emergy inputs, and carbon sequestration benefits across all life cycle stages and calculating core indicators including the net carbon payback period, emergy sustainability index, carbon–emergy trade-off coefficient, and comprehensive performance index. The results showed that the ecological engineering case achieved a net life cycle carbon emission of 2.0 tons CO 2 e, a 99% reduction from the conventional case; the net carbon payback period decreased from 65 years to 10 years; the total emergy input was reduced by 72%, and the emergy sustainability index improved from 0.13 to 0.61; the comprehensive performance index was 2.74. Sensitivity analysis confirmed the robustness of the evaluation results. The proposed carbon–emergy trade-off coefficient and comprehensive performance index represent the primary methodological contributions of this study as they reveal the relative improvement rates between carbon emission reduction and resource consumption improvement—information unattainable through single-method approaches—and provide a flexible multicriterion decision-support tool with adjustable dimensional weights. The integrated framework effectively distinguishes the environmental performance differences between restoration alternatives and provides a scientific basis for alternative comparison and design optimization of coastal park ecological restoration.