Assessing Future Tropical Cyclone Risk Using Downscaled CMIP6 Projections
The authors employ the Columbia Hazard model (CHAZ) to characterise future tropical cyclone (TC) activity under the shared socioeconomic pathways (SSP) SSP2-4.5, SSP3-7.0, and SSP5-8.5 by downscaling 12 models that participated in the Coupled Climate Model Intercomparison Project’s sixth generation...
| Published in: | Journal of Catastrophe Risk and Resilience |
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| Main Authors: | , , , , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2024
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| Subjects: | |
| Online Access: | https://research.vu.nl/en/publications/bede1aad-df0c-46ea-bf6b-7f3b1482ef64 https://doi.org/10.63024/dpva-2pa1 https://hdl.handle.net/1871.1/bede1aad-df0c-46ea-bf6b-7f3b1482ef64 |
| Summary: | The authors employ the Columbia Hazard model (CHAZ) to characterise future tropical cyclone (TC) activity under the shared socioeconomic pathways (SSP) SSP2-4.5, SSP3-7.0, and SSP5-8.5 by downscaling 12 models that participated in the Coupled Climate Model Intercomparison Project’s sixth generation (CMIP6), focusing on the Western North Pacific (WNP) and North Atlantic (ATL) basins. Results from CHAZ are also used in conjunction with the Impact Forecasting Atlantic/Caribbean Tropical Cyclone Wind Model, an industry catastrophe model, to project future changes in financial losses in the ATL. As with previous downscaling of CMIP5 models in CHAZ, projections of TC frequency depend on the choice of moisture variable used in the tropical cyclone genesis index (TCGI), despite similar trends when the two are applied in the historical period. Simulations using column relative humidity (CRH) project an increasing TC frequency trend in the future, while those using saturation deficit (SD) project a decrease. In the WNP, TC frequency scales linearly with the rise in global mean surface temperature, highlighting a direct link with anthropogenic greenhouse gas (GHG) radiative forcing. While ATL TC frequency in the SD experiments exhibits the same trend, the CRH response is complex and nonlinear, probably due to the higher sensitivity of the response of TC potential intensity to aerosol versus GHG forcing. Our projections of financial losses are equally uncertain, consistent with the corresponding bifurcation in TC frequency between the CRH and SD experiments. These projections, despite their inherent uncertainties, can still be useful if viewed as placing bounds on future changes in risk, since not very large increases (i.e., much greater than around 10%) are projected in any of the ATL loss results. 1. Introduction |
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