Sahara greening may have diminished mid-Holocene Atlantic tropical cyclones

While anthropogenic warming is projected to green the Sahara region, the potential impacts on tropical cyclone remain poorly understood. Here we examine the mid-Holocene Sahara greening (characterized by expanded vegetation and reduced dust emissions) as a potential analog for the future, combining high-resolution global atmospheric model simulations with paleoclimate proxy records. The simulation results demonstrate that without Sahara greening, the mid-Holocene tropical cyclone distribution resembles the pre-industrial pattern, albeit with an eastward shift of tropical cyclone genesis in the North Pacific. The greening of Sahara dramatically reduced North Atlantic tropical cyclone frequency to near-zero levels while causing minimal changes in other basins. The greening-induced tropical cyclone suppression primarily resulted from enhanced vertical wind shear off West Africa and reduced low-level moisture over the western tropical North Atlantic. These findings align with reconstructed North Atlantic tropical cyclone variability and may provide insights into its future activity under anthropogenic Sahara greening.