By chemically analysing crystals in ancient rocks, a team of international scientists discovered that as glaciers carved through the landscape, they scraped deep into the Earth's crust, releasing key minerals that altered ocean chemistry.
This process had a profound impact, creating conditions that allowed complex life to evolve. When these giant ice sheets melted, they triggered enormous floods that flushed minerals and their chemicals, including uranium, into the oceans.
Uranium helped create the right conditions for life by changing ocean chemistry. It boosted oxygen levels in the water, helped cycle nutrients that supported early life, and even contributed to underwater heat sources that may have fueled life's development.
The study, published in the journal Geology, was a collaboration between the University of Portsmouth in England, Curtin University in Australia, and St. Francis Xavier University in Canada.
Co-author, Emeritus Professor Rob Strachan , from the University of Portsmouth's School of the Environment and Life Sciences , said: "Our research shows that ancient glaciers did far more than shape the landscape - they triggered chemical transformations that helped set the stage for complex life. These findings highlight the deep connections between Earth's geology, climate, and the evolution of life itself."
The research also offers a new perspective on modern climate change, showing how past shifts in Earth's climate triggered large-scale environmental transformations.
Lead author Professor Chris Kirkland from the Timescales of Mineral Systems Group within Curtin's Frontier Institute for Geoscience Solutions explained: "This research is a stark reminder that while Earth itself will endure, the conditions that make it habitable can change dramatically.
"These ancient climate shifts demonstrate that environmental changes, whether natural or human-driven, have profound and lasting impacts. Understanding these past events can help us better predict how today's climate changes might reshape our world."
