Characterization and Attribution of Historical Extreme Cold Events in China-Pakistan Economic Corridor

Long-term regional extreme cold events (ECEs) garner significant attention due to their widespread impact and prolonged duration, posing critical threats to human society and ecosystems. Previous studies have examined ECE characteristics at single sites or grid points, however, it is crucial to recognize that such events generally manifest as spatiotemporally continuous regional phenomena. Here, we proposed an objective methodology based on spatiotemporal continuity to identify ECEs in the China-Pakistan Economic Corridor (CPEC) during the winters of 1961–2015. This approach successfully reproduced the dynamic evolution of ECEs, encompassing their initiation, development, and dissipation. We further analyzed the changes of ECE intensity, frequency, and duration, and assessed ECE trends within varying return periods by employing the generalized Pareto distribution (GPD). Our findings reveal a decline in the frequency and duration of ECEs in CPEC over the study period, while their intensity has increased by 50%. ECEs predominantly occur in the northern regions of Azad Kashmir and Balochistan’s Quetta in Pakistan, and Kashgar in China. High recurrence levels are associated with an expansion of ECE-prone areas, particularly in the northern Pamir Plateau, which emerges as a regional hotspot. These results highlight the critical need to remain vigilant to potential future surges in ECEs under global warming, underscoring their implications for regional climate resilience.