Simulating Continental Dust on a Hard Snowball Earth: 1. Limited Dust Emission

During the Cryogenian Period, Earth may have experienced two global‐scale glaciations in ∼720–635 million years ago (Ma), referred to the Sturtian and Marinoan Glaciations, known as the “snowball Earth”. During the snowball Earth, continental dust emissions from unglaciated regions were hypothesized to have played a pivotal role in the snowball Earth climate. Using an atmospheric general circulation model with an interactive dust module and an ice sheet model, we explicitly simulate continental dust emission on a hard snowball Earth. We find that the strength of continental dust emissions is within 494–3,051 Tg yr −1 , which is comparable to or even less than the modern Earth (2,566 1,966 Tg yr −1 ) and is about one order less than previous estimations. Compared with the present Earth, the main factors for the limited dust emission during the snowball Earth are extended ice sheet cover, seasonal snow cover, and frozen soil, which strongly suppress dust emission from the land surface.