By analyzing the Intergovernmental Panel on Climate Change (IPCC) projections, we find a physically solid rationale for expecting that Atlantic tropical cyclone activity could gradually decrease over the 21st century. When the tropical North Atlantic is cool (warm) and the Atlantic warm pool is small (large), both the vertical wind shear and the moist static stability over the main development region (MDR) for hurricanes increase (decrease) while tropical cyclone activity decreases (increases). From the IPCC multi-model data set, we find that the North Atlantic warms more slowly than other oceans as the Atlantic meridional overturning circulation (AMOC) decreases, whence a physically consistent scenario, confirmed by IPCC projections, suggests that the atmosphere should respond as if to a small (cool) warm pool and the vertical wind shear and the moist static stability over the MDR should increase, causing tropical cyclone activity to decrease.

Last Updated: 2007-12-17