Collective coupling and topological reorganization under climate stress: evidence from China’s urban energy financial network

Climate stress may alter the collective organization of interdependence in financial markets. Systematic evidence on this process within urban energy finance remains limited. Using daily stock returns of Chinese A share listed energy companies, this study aggregates market information from individual firms to the city level. It then constructs a dynamic urban energy financial network for the period from 2021 to 2025. The analysis combines annual changes in network topology with rolling network states. It examines the relationship between external climate stress and changes in both the strength of financial linkages across cities and the organization of the network. The results indicate that higher climate stress is associated with stronger weighted coupling and tighter local organization. Compared with periods of lower climate stress, periods of higher climate stress show stronger network connections, greater structural concentration, and a higher degree of overall integration. These patterns indicate that topological reorganization varies systematically across climate conditions. Further analysis shows that peripheral nodes also participate actively in network adjustment, with significant increases in weighted connectivity and local clustering. The main findings remain broadly stable across alternative network thresholds, time windows, and city sample definitions. This study integrates market signals from individual firms, dynamic network states, and the external climate environment within a unified temporal framework. It provides new empirical evidence on the complex network dynamics of energy finance under climate stress.