Synergistic Pathways to Carbon Neutrality in China: Multi-Criteria Evaluation of Urban Metabolism, Ecological Restoration, and Direct Air Capture

Abstract

 China's commitment to carbon neutrality by 2060 cannot be met through emission cuts alone; the residual emissions from hard-to-abate sectors must also be offset by carbon removal. Mitigation and removal, in other words, are two halves of a single strategy. To date, researchers have largely examined urban metabolism optimization, ecological restoration, and direct air capture (DAC) as separate topics, leaving their combined potential and regional variation underexplored. This paper addresses that gap by constructing an evaluation framework that couples the analytic hierarchy process (AHP) with the entropy weight method. Each pathway is scored along four dimensions—carbon reduction potential, cost-effectiveness, technical maturity, and scalability—with weights derived from both expert judgment and data variability. Drawing on IPCC AR6, IEA 2024, and Chinese official statistics, we compare a baseline scenario against an enhanced scenario and disaggregate the results by eastern, central, and western China. Four findings emerge. Urban metabolism regulation dominates, accounting for 42–43% of projected 2030 emission reductions. Ecological restoration offers the lowest unit cost (USD 17–21 per ton of CO₂) and strong life-cycle net benefits. DAC remains supplementary before 2040 but gains importance thereafter as costs fall. Regional heterogeneity is pronounced: the east should prioritize urban metabolism, the center a balanced mix, and the west ecological restoration. Under the enhanced scenario, the three pathways together could deliver 1.5–1.8 Gt of annual CO₂ reduction by 2035. These results provide empirical support for a phased, regionally differentiated decarbonization strategy.