Ancient volcanoes released ‘cryptic’ carbon dioxide far longer than previously believed

Ancient volcanoes released carbon dioxide into Earth’s atmosphere for millions of years after eruptions ended, scientists have found. This process, called “cryptic degassing,” occurred even after surface eruptions stopped. Researchers say this prolonged carbon release could explain why Earth experienced extended warming periods after major volcanic events.

About 250 million years ago, a series of massive eruptions in Siberia caused Earth’s most severe mass extinction. Scientists previously believed volcanic carbon emissions would decrease quickly, allowing the climate to stabilize. However, new research shows these emissions continued from deep within Earth’s crust and mantle, keeping the atmosphere warmer for much longer.

An international team led by Rutgers University and including Dr. Jack Longman from Northumbria University studied volcanic rocks and created computer models to simulate Earth’s interior processes. They compared these with ancient climate records in sedimentary rocks, revealing a source of hidden carbon dioxide that contributed to warming far beyond the initial eruptions.

This finding helps explain the extended warm periods in Earth’s past and highlights a new area of research into volcanic impacts on climate. Scientists emphasize that while this ancient carbon source doesn’t contribute to present-day climate change, it offers valuable insights for understanding long-term climate shifts.