Projected Future Changes in Tropical Cyclones Using the CMIP6 HighResMIP Multimodel Ensemble

Future changes in tropical cyclone properties are an important component of climate change impacts and risk for many tropical and midlatitude countries. In this study we assess the performance of a multimodel ensemble of climate models, at resolutions ranging from 250 to 25 km. We use a common experimental design including both atmosphere‐only and coupled simulations run over the period 1950–2050, with two tracking algorithms applied uniformly across the models. There are overall improvements in tropical cyclone frequency, spatial distribution, and intensity in models at 25 km resolution, with several of them able to represent very intense storms. Projected tropical cyclone activity by 2050 generally declines in the South Indian Ocean, while changes in other ocean basins are more uncertain and sensitive to both tracking algorithm and imposed forcings. Coupled models with smaller biases suggest a slight increase in average TC 10 m wind speeds by 2050. Tropical cyclones pose great risks to individuals and societies, particularly in terms of their local impacts, and how such risks may change in the future is a key question. In this work we use a common experimental framework with seven different state‐of‐the‐art global climate models, together with two different methods of identifying tropical cyclones. We find that the simulation of tropical cyclone frequency, spatial distribution, and intensity in some models approaches observed values with the model grid spacings of 20–50 km. Future projections to 2050 suggest that activity will generally decline in the South Indian Ocean while a more mixed picture is revealed in other regions. Biases in tropical cyclone distribution, frequency, and intensity are generally reduced in models at 25 km resolutionNorthern Hemisphere basins show mixed responses to future forcing, while Southern Indian Ocean activity projected to declineFuture changes in 10 m wind speed in coupled models are mixed, and models with lower bias suggest small increases