Overview

• A peer-reviewed Science paper by Dominik Hülse and colleagues, co-authored by UC Riverside’s Andy Ridgwell, adds a missing nutrient–plankton–oxygen pathway to Earth’s long-term carbon cycle.
• Warming increases nutrient runoff to the oceans, fueling plankton growth that buries carbon as organisms sink, while deoxygenation recycles phosphorus and intensifies the burial feedback.
• Model experiments show this mechanism can overcorrect warming and cool the planet below its initial state, potentially reaching ice-age-like conditions.
• The strength of the feedback depends on atmospheric oxygen, with lower oxygen in the past allowing extreme glaciations and modern higher oxygen likely weakening the response.
• The authors caution that any cooling would occur on geological timescales measured in tens to hundreds of thousands of years, reinforcing the need for rapid emissions cuts now.