The European Union’s natural gas policy has undergone a profound transformation since the energy crisis began in 2021. In response to supply disruptions and price volatility, policymakers swiftly expanded the existing 2017 security of supply framework by introducing a series of new regulations, aiming to provide a swift and coordinated EU reaction to the gas crisis. They supplemented the existing strategies of diversifying supply and improving infrastructure with several new measures, including optimizing storage utilization, reducing gas demand, and enhancing cooperation and solidarity among EU Member States. Four years after the start of the crisis, the natural gas system has stabilized to a new status quo, providing an opportunity to retrospectively analyze the system’s resilience to shocks. In this paper, we present the EU’s natural gas policy since the First Gas Directive, providing context and highlighting measurable policy targets. Based on this policy context, we then identify metrics to evaluate the resilience of the EU natural gas system from the perspectives of supply, demand, infrastructure, and prices. Finally, we analyze publicly available datasets on these resilience indicators to evaluate whether the system’s development over time aligns with the outcomes intended by policy and we demonstrate the suitability of these indicators to evaluate EU policy response and implementation. We conclude that the general development was in line with the intended policy trends.

The increasing frequency and severity of significant risks to public safety posed by natural disasters or human-induced events have underscored a critical need for evaluating the vulnerability of urban regions with a focus on their essential infrastructures. This paper presents a novel methodology for the virtual representation of infrastructure vulnerabilities and functional impairments during hazard situations. Thereby, focus is on the mapping of interdependencies among critical infrastructure systems and the cascading effects that can arise from failures within these heterogeneous sectors by means of a digital twin representation. An integration of simulation models for urban infrastructure components, particularly in relation to the built environment and emergency response systems is introduced. Leveraging a modular co-simulation architecture, the framework facilitates the analysis of cascading effects across multiple infrastructure systems, such as water, electricity, gas, and telecommunications. As a proof-of-concept example, urban flooding due to heavy rainfall is considered to illustrate the framework’s capabilities in predicting system states and assessing structural impacts on critical infrastructures as well as consequential ramifications for emergency relief units. The findings contribute valuable insights, thereby advertising the utilization of the presented methodology in decision-making and training resources aiding the enhancement of the resilience of urban environments against both natural and intentional threats.