Snowball Earth hypothesis: Development and challenge

Since the first discovery of Neoproterozoic glacial deposits in 1871 and the subsequent confirmation of similar glacial deposits widely distributed across different continents in 1931, this distinctive global geological phenomenon has been widely concerned by geologists. With the development of plate tectonics and paleomagnetic research, two classic articles published in the 1990s laid the foundation for the Snowball Earth hypothesis. These two studies first used the term “Snowball Earth” to explain low-latitude glaciation during the Neoproterozoic and systematically proposed the Snowball Earth hypothesis, making it a research hotspot in international geologic and climatologic fields. This paper highlights these two classic publications and revisits how the scientific hypothesis was developed on the basis of geological phenomena. The Snowball Earth hypothesis explains the mechanisms and processes of cap carbonate deposition, abnormal carbon isotope compositions, banded iron formation (BIF) deposition, and the synchronous onset and termination of global glaciation events. Unlike the well-established theory of plate tectonics, the Snowball Earth hypothesis—though supported by multiple lines of evidence—remains a scientific proposition subject to doubts and challenges. Key contradictions arise from sedimentological, paleontological, and geochemical records, suggesting the need for further research to clarify its scientific validity. Accordingly, we review the development and challenges of the Snowball Earth hypothesis over the past 30 years, with the aim of providing a reference for future research.