From policy-related proxy indicators to scenario space optimization: Carbon-neutrality-oriented emission reduction pathways for the building sector in Shaanxi Province, China

With China's carbon-peaking target being progressively advanced, identifying key emission drivers and feasible reduction pathways in the building sector is essential for supporting the transition toward carbon neutrality. To address the limitations of conventional driver analysis and limited predefined scenarios, this study develops an integrated framework combining implementation-oriented policy-related proxy indicators, Ridge–STIRPAT estimation, feasible scenario-space construction, sensitivity analysis, and stage-wise interval-constrained optimization. Taking Shaanxi Province as a case study, the results show that building-sector carbon emissions increased from 25.83 MtCO 2 in 2001 to 318.09 MtCO 2 in 2022, with an average annual growth rate of 13.73%. Material production and transportation were the dominant sources, accounting for up to 76.19% of total emissions. Although carbon emission intensity declined from 9.23 to 2.39 tCO 2 /10 4 CNY, stable decoupling from economic growth was not achieved. Steel consumption was the dominant sensitivity factor, contributing 60.23% of the Shapley effect, followed by GDP, building electricity consumption, clean-heating proportion, and the electricity emission factor at 8.08%, 5.58%, 5.02%, and 3.02%, respectively. Under the constrained future scenario, median emissions rise to 338.74 MtCO 2 in 2030 and then decline to 164.54 MtCO 2 in 2060, corresponding to a reduction of approximately 48%–51% from 2022. Material-efficiency, power-decarbonization, building-operational-efficiency, and construction-stock-transition pathways achieve similar long-term outcomes. Under the Expanded stress-test scenario, the 2060 median falls to 85.59 MtCO 2 , while the screened high-implementation-potential pathways reach 102.03 MtCO 2 , representing a 67.92% reduction and retaining 92.93% of the original stress-test reduction. These findings highlight coordinated material-demand control, power-system decarbonization, building-energy-efficiency improvement, and construction-stock transition as the core of differentiated low-emission pathways.