Researchers say Earth may have had a long-running natural climate regulator tied to the oceans. According to the new findings, a hidden feedback between sea level, ocean oxygen, phosphate, and carbon burial may have helped keep the planet’s climate in check for roughly 60 million years.
The study points to a narrow set of ocean conditions that allowed carbon burial to work especially well for millions of years at a time. When more carbon was buried in sediments, it was effectively locked away from the active carbon cycle, creating a stabilizing effect on climate over very long timescales.
Scientists say geological evidence supports the idea that this ocean-based process acted like a thermostat. Changes in sea level appear to have influenced oxygen and nutrient conditions in the ocean, which then affected how much carbon could be stored away. That link may have created a feedback loop strong enough to moderate climate shifts across vast stretches of Earth’s history.
The research adds to understanding of how the planet regulates itself beyond short-term weather and seasonal changes. It also highlights how closely Earth’s climate is connected to ocean chemistry, sea level, and the slow movement of carbon through the planet’s systems.
