An eruption of the Campi Flegrei (Phlegraean Fields) supervolcano near Naples, Italy, would be a catastrophic event with local, regional, and potentially global consequences. Locally, the immediate "Red Zone" is home to approximately 500,000 people who would require urgent, mass evacuation to escape pyroclastic flows and heavy ash fall. A major explosion in the Gulf of Pozzuoli could also trigger tsunamis with waves tens of meters high, devastating coastal infrastructure in Naples and Sorrento. Regionally, the ash cloud would likely ground all air traffic across Europe and disrupt telecommunications and power grids. In a worst-case "super-eruption" scenario—similar to the Campanian Ignimbrite event 39,000 years ago—the volume of sulfur dioxide and ash injected into the stratosphere could cause a "volcanic winter," leading to a significant drop in global temperatures and widespread crop failures for several years. While modern monitoring by the INGV provides early warning signals, the sheer density of the population and the complexity of the volcanic system make any significant eruption one of the most high-stakes natural disaster scenarios in the developed world.