Unveiling the Impact of Andean Volcanism on Earth’s Ancient Climate
Recent research sheds light on a fascinating period in Earth’s history where volcanic activity in the Andes may have significantly altered the planet’s climate. This study, led by Mark Clementz of the University of Wyoming, explores how volcanic eruptions during the Late Miocene Epoch possibly cooled the Earth by affecting oceanic and atmospheric conditions.
Published in Nature Communications Earth and Environment, the article titled “Andean volcanism, ocean fertilization, marine ecosystem turnover, and global cooling in the Late Miocene” outlines how increased volcanic activity in the Andes led to a boom in marine life in the Southern Ocean. This biological surge contributed to a drawdown of atmospheric carbon dioxide, which in turn, led to global cooling.
“The Late Miocene represents a pivotal transition in Earth’s climate system,” says Clementz. This period marked a shift towards modern climatic conditions and the development of current ecosystems. Understanding these changes provides insights into how Earth’s systems might react to present and future climate shifts.
This research was a collaborative effort supported by the National Science Foundation, involving experts from institutions such as the University of Arizona, Universidad de Buenos Aires, University of Colorado-Boulder, University of Birmingham, Lehigh University, University of Bremen, and Universidad Santo Tomás.
The team utilized a combination of multi-proxy data from field and laboratory research, along with computer modeling, to investigate the effects of sustained volcanism in the Altiplano-Puna volcanic complex. This region is known for its large active silicic magma system, which potentially influenced global climate and ecological changes.
Volcanic ash from the Andes, rich in nutrients like phosphorus, iron, and silicon, likely fertilized the Southern Ocean, boosting the growth of diatoms. These microscopic algae are crucial for ocean food chains and are significant producers of chlorophyll, playing a key role in reducing atmospheric carbon dioxide.
Fossil records from this era indicate significant shifts in marine vertebrate populations, especially cetaceans, which underwent evolutionary changes such as increased body size and diversified migratory behaviors. Whales, by sequestering carbon at the ocean floor and producing carbon-rich feces, may have contributed to reducing atmospheric carbon dioxide levels.
Models from the study suggest that these processes led to a reduction in atmospheric carbon dioxide by 10-15 parts per million, contributing to a cooler global climate during the Miocene. “This work improves our understanding of how natural processes can regulate Earth’s climate,” Clementz remarks, highlighting its relevance to current climate change discussions.
Clementz hopes this research will guide science-based policy decisions regarding natural resources and climate resilience. This study also emphasizes Wyoming’s pivotal role in Earth system science, given its rich paleontological history.
For the complete study, visit: www.nature.com/articles/s43247-026-03457-4. More insights on the research can be found on Carrapa’s blog at this link.
Original Story at www.uwyo.edu