Hurricane Ida’s blackout-heatwave compound hazard risk in a changing climate

Abstract The emerging tropical cyclone (TC)-blackout-heatwave compound hazard under climate change are not well understood. In this study, we employ future projections of TCs, sea levels, and heatwaves, in conjunction with power system resilience modeling, to evaluate historical and future TC-blackout-heatwave compound hazard risks in Louisiana, US. We find that the return period for a compound hazard event comparable to Hurricane Ida (2021), with approximately 35 million customer hours of simultaneous power outage and heatwave exposure in Louisiana, is around 278 years in the historical climate (1980-2005). Under the emissions scenario SSP5 8.5 (SSP2 4.5), this return period may decrease by a factor of ~17×(10x) to 16.2 (28.4) years in the future climate (2070-2100). The significant increase in risk can be primarily attributed to projected escalations in heatwaves, which result in an approximate 5(2)-fold decrease in compound hazard return period, and in TC activity, which cause an estimated 2(1)-fold decrease in the return period. The findings contribute to our knowledge of and adaptation to compound climate hazards.