106AMS Presentation "4B.5 - Intercomparing Attribution Methods for Hurricane Milton's Intensity" by Gilford et al. (1/26/26)

4B.5 - Intercomparing Attribution Methods for Hurricane Milton’s Intensity Authors: Daniel M. Gilford (corresponding author, [email protected]), Ralf Toumi, Nathan Sparks, Stella Bourdin, Huanping Huang, Mireia Ginesta, Davide Faranda, Harish Uppu, Emily Bercos-Hickey Abstract: Observations suggest that major Atlantic hurricanes are becoming more intense, and the causes of these historical changes remain an active area of research. It is critical to understand human-caused influences on tropical cyclone intensities, because even modest increases in wind speed can lead to substantially greater storm damages and coastal impacts. Several methodological approaches have recently emerged to assess the extent to which observed changes in hurricane intensity can be attributed to climate change. Using Hurricane Milton (2024) as a case study, this work intercompares results from four distinct attribution methods, aligned across common datasets and a shared global warming-level baseline. We quantify how much climate change may have intensified Milton—both at its lifetime maximum intensity and at landfall—per degree of global warming. Preliminary analyses reveal an average positive climate signal, though the magnitude and range of the effect varies widely across methods due to differing model structures and assumptions. To explore the real-world implications of these differences, we use a simple damage model to estimate the impacts associated with each method’s attributable intensity increase. While most approaches indicate rising damages, the range of these estimates is method-dependent. By identifying both uncertainties and shared outcomes, this work demonstrates how methodological diversity and intercomparison strengthens hurricane attribution science and improves hurricane risk analyses and communication.