Estimating Tropical Cyclone Damages Under Climate Change in the Southern Hemisphere Using Reported Damages

This paper estimates the damages from tropical cyclones (TCs) in the Southern Hemisphere under future climate change scenarios based on the historical TC records in Australia. From the best-track TC data, we examine the changes in frequency, intensity, and economic damage of the TCs that made landfall since 1970. From the detailed individual TC reports, damage estimates are constructed based on reported damages. We find that the TC frequency has significantly declined over time. The intensity, however, does not show a significant trend. Average damage per TC has declined significantly from 43 million AUD in the 1970s to 11 million in the 1990s. This paper finds that 1 % decrease in minimum central pressure leads to 32.7 % increase in economic damage, which is more than three times larger than that found in the US hurricane study with regards to maximum wind speeds. For future damage projections, characteristics of the 14,000 TCs generated under seven different AOGCM climate models are applied. All seven climate models predict a decrease in TC frequency in the Southern Hemisphere but intensity predictions vary. By the end of the twenty second century, changes in climate are expected to increase the TC damage under the MRI (94 %), the MIROC (73 %), and the CSIRO (66 %) model due to increased intensity. However, TC damage is expected to fall under the GFDL (92 %) and the CNRM (85 %) model due to decreased intensity and frequency. Adaptation will be a key determinant of the future vulnerability to TCs in the Southern Hemisphere.