Synergistic impact of marine heat waves and rapid intensification exacerbates tropical cyclone destructive power worldwide.

Tropical cyclones (TCs) are among the most devastating natural phenomena, causing substantial economic damage and severe impacts on human life and infrastructure. Prolonged extreme ocean temperature events, known as marine heat waves (MHWs), affect 52% of landfalling TCs globally and provide favorable conditions for TC rapid intensification (RI). Here, we use four decades of global data to demonstrate that TCs experiencing RI during MHWs resulted in 60% more billion-dollar disasters compared to those without heat wave influence. Our analysis reveals these costlier storms produced consistently higher maximum wind speeds, storm surges, and precipitation rates. We found that, for billion-dollar TCs, even controlling for similar levels of coastal development, MHW TCs cause significantly higher damages than their counterparts, confirming that their enhanced intensity characteristics amplify economic impacts beyond what would be expected from exposure alone. These findings underscore the critical need for improved disaster preparedness as MHWs increasingly supercharge TCs' intensity, leading to more frequent billion-dollar disasters.