Kyrgyz Republic

The predictability of future tropical cyclones is marked with significant uncertainties due to several factors. These include disparities among climate models, the inherent complexity of processes incorporated into Tropical Cyclone Models, and regional variations in cyclone formation, behavior, and dispersal. Moreover, Tropical Cyclone Models are primarily calibrated for current climate conditions, which may introduce additional biases when applied to future scenarios. In summary, the complex and often conflicting interactions among ocean temperatures, wind patterns, and atmospheric conditions that drive cyclone formation, dispersal, and landfall remain poorly understood, making it challenging to identify which trends will dominate. For additional information on current understanding of tropical cyclones and tropical cyclone frequency, see Sobel et al. (2021). However, a few certainties do emerge in the projections. The clear trend of warming indicates that, once storms form and conditions become favorable, the intensities of these storms are likely to increase as compared to today. This signal is particularly pronounced for major tropical cyclones, as highlighted in the IPCC AR6 WG1 Report.

This page uses projections from the Columbia HAZard Model (CHAZ, Lee et al. 2018 ). These projections are derived from outputs of 12 CMIP6 GCMs under the SSP2-4.5 Scenario, focusing on the period 2035-2064 (centered on 2050). It’s important to note that the CHAZ model does not include projections for cyclone activity in the South Atlantic, based on the assumption that low cyclone activity will continue in the near future. Another important caveat is that CHAZ uses two configurations to represent moisture: the model with column relative humidity (CRH), used here, projects an increasing tropical cyclone frequency in the future, while the model using saturation deficit (SD) projects a decrease. In the Western North Pacific, cyclone frequency scales linearly with the rise in global mean surface temperature, highlighting a direct link to anthropogenic greenhouse gas radiative forcing. In the Atlantic, the SD experiments show the same trend, but the CRH response is more complex and nonlinear, likely due to the higher sensitivity of cyclones to aerosol forcing compared to greenhouse gas forcing. However, in both configurations, the percentage of intense cyclones is increasing, making this a consistent and reliable trend. For a review of tropical cyclone models, see Knutson et al. (2020).

Currently CCKP presents a single cyclone model, configuration, and scenario for the initial presentation of this complex subject matter.  

CCKP is grateful for the expertise and guidance of the CHAZ Model Team at Columbia University.