Yuqing Wu

Achieving urban carbon neutrality requires not only ambitious mitigation targets but also urban conditions capable of supporting implementation. However, whether cities possess such transition capacity remains insufficiently understood. Here, we develop an empirical framework to evaluate urban transition capacity across 336 Chinese cities by integrating carbon emission characteristics, policy and technology, ecological endowment, and energy potential. We identify substantial heterogeneity: 40 cities are classified as high-capacity, while most cities fall into medium- or low-capacity groups with systematically different obstacle compositions. High-capacity cities exhibit stronger conditions across all four capacity dimensions, but weighted obstacle structures shift progressively across groups. Policy and technology represent the largest relative obstacle component throughout, whereas the contribution of carbon emission characteristics increases markedly as transition capacity declines. Together, these results link multidimensional capacity assessment with group-specific obstacle diagnostics across a large urban system. The findings question the suitability of uniform mitigation strategies across heterogeneous urban contexts and support capacity-oriented governance that aligns transition priorities with city-specific conditions.

Fiscal shocks in post-land-finance China are weakening the funding basis of capital-intensive metro public-private partnership (PPP) projects, but the system-level mechanism through which public fiscal stress becomes subcontractor-level financial viability pressure remains underexplained. This study examines a section-level metro PPP project ecosystem in a sub-provincial Chinese city to trace this transmission mechanism and its financial implications. The analysis combines de-identified audit evidence and interviews with a scenario-based structural NPV model and 800,000 model-generated Monte Carlo realizations under calibrated institutional scenarios. The evidence indicates that quasi-bureaucratic SPV internal capital-market arrangements convert fiscal shortfalls into vertical and horizontal cross-subsidization practices, preserving short-term project continuity while shifting cash-flow pressure downstream. This condition is defined as a strategic resilience trap: practices that preserve short-term project continuity while potentially eroding the project ecosystem’s long-term adaptive capacity. Under calibrated assumptions, improving the contract-payment channel reduces model-generated losses by approximately 4%, suggesting that payment punctuality addresses only one part of the wider internal capital-market mechanism.