2025 Hatherton Award: A piece of the historic puzzle about climate change
Sofia Rauzi from Te Whare Wānanga o Waikato – the University of Waikato has won the Hatherton Award for her paper that helps to answer a long-standing question about historic climate change through lithium isotopes in sedimentary rocks.
Sofia’s research focused on the puzzle of why, after massive volcanic eruptions in the Permian period caused catastrophic climate change, the high temperatures persisted for 5 million years longer than would be expected.
Sofia’s approach was to assess the ratio of lithium isotopes in marine shales as a proxy for formation of marine clay throughout this warm period.
She used the ratios of lithium isotopes in these marine sediments, together with model simulations, to show that clay formation in the marine environment remained elevated during this period. This elevated clay formation potentially sustained the high temperatures by releasing dissolved carbon dioxide into the atmosphere and slowing the natural processes that remove carbon from the atmosphere.
Sofia says writing and publishing a paper for the world to read has been a nerve-racking experience, and hearing that it has been well received has been “very rewarding and such a relief”.
“Receiving the Hatherton Award for this project has been so encouraging and motivated me to get a move-on with my current work. This project is as much Terry Isson’s as it is mine and I’m so grateful we got to work on it together.”
Sofia says she and her team are continuing to investigate the role of clay formation in the global climate system in both modern and deep times.
“In addition to using lithium isotopes, we're working to develop other novel isotope-proxies to track clay formation.
“As for me personally, I'm finishing up my PhD next year and seeking postdoctorate opportunities, I’m not sure where I'll go yet.”
Sofia says she’s excited to try and reconstruct conditions on Earth millions or billions of years ago.
“You essentially compile as many clues as you can and then try and figure what one tiny aspect of what the planet was like. It feels analytical and creative at the same time.”
Hatherton Award:
For the best scientific paper by a PhD student in mathematics, physical sciences, earth sciences, or information sciences.
Citation:
To Sofia Rauzi for lithium isotope measurements that have provided evidence for the cause of prolonged warmth following the end-Permian mass extinction, generating insight into climate-regulation mechanisms.