Will Tropical Cyclones Grow Stronger with Global Warming?

1. Will Tropical Cyclones Grow Stronger with Global Warming? Jinhua Yu, Yuqing Wang, and Kevin Hamilton Change in maximum potential tropical cyclone wind speed: eastern North Pacific 2.41%, western North Pacific 2.33%, North Indian Ocean 3.26%, South Indian Ocean 3.39%, Southwest Pacific 1.03%, off U.S. southeast coast 2.38% Mean percentage change over 70 years in tropical cyclone potential intensity (based on thermodynamical and dynamical factors) in response to increased CO2 concentration in the IPCC-AR4 1pctto2x scenario from a 15 CGCM ensemble for July–October (top) and January–March (bottom). Contours show the initial background PI (m/s). The potential intensity (PI) relates the large-scale atmospheric thermal and dynamical environment to the peak wind speed of the strongest tropical cyclones expected to develop. In this study, the PI concept has been applied to coarse-resolution global climate model projections in order to assess the possible changes in tropical cyclone intensity under anticipated global warming conditions. The figure shows the change in PI in response to a transient doubling of atmospheric CO2 as projected in a multi-model ensemble. Little change is seen over the North Atlantic, but in the other ocean basins the PI is projected to increase by ~1.0% to 3.4%. The destructiveness of landfalling storms is roughly proportional to the cube of the maximum wind speed, so this indicates that over much of the globe there will be a substantial increase in the destructiveness of the most dangerous storms under the global warming conditions anticipated later this century.