Wind Versus Rain: Tropical Cyclone Losses Under Climate Change

Abstract for Weekly Colloquium on Thursday, November 30, 2017 at 4 pm in Harshbarger 206 ~ Refreshments at 3:45 pm

Laura Bakkensen, Assistant Professor, School of Government and Public Policy, University of Arizona

Wind Versus Rain: Tropical Cyclone Losses Under Climate Change (Laura Bakkensen , Doo-Sun Park , Raja Sarkar)

Abstract

While a growing literature analyzes the current and future losses from tropical cyclones (TCs), almost all have characterized TCs by wind speed, or related intensity derivatives, alone. However, TC wind is almost always accompanied by rainfall, both of which will likely be impacted by climate change. Using an original dataset from 1979 to 2010 containing the complete history of weather-station level records and official government data on local-level damages, fatalities, and homelessness from TCs striking South Korea, we analyze the differential impacts of wind versus rain on tropical cyclone losses. We find the omitted rainfall variable to be a significant determinant of losses. Next, using 60,000 simulated TCs across current and future (RCP8.5) climates, as estimated by six general circulation models within our Tropical Cyclone Integrated Assessment Model, we analyze the impact of climate and socioeconomic change on cyclone losses. We find that socioeconomic change will decrease physical harm to people, but greatly increase losses to property, from approximately $575 million (2005USD) to almost $2 billion per year. Little variation in average impacts results from changes in wind intensity, leading to an underestimate of future losses across many specifications. Instead, future damages in South Korea will increase significantly from an estimated $2 billion to $6.7 billion per year, due largely to intensifying rainfall patterns. While the relative impacts of cyclone wind versus rain under climate change is likely to be heterogeneous across countries, it is important to account for both in research and policy decisions.