Scientists Identify Natural Carbon Thermostat in Global Oceans

Scientists have identified a hidden feedback loop that acts as a planetary thermostat by regulating carbon burial in the open ocean ^[1].

This discovery explains how the Earth has maintained climate stability over vast geological timescales. By understanding the mechanism that removes carbon dioxide from the atmosphere, researchers can better grasp the natural systems that prevent extreme temperature swings on a global scale ^[2].

The process relies on a complex interaction between sea-level fluctuations and the delivery of phosphate to the open ocean ^[1]. Phosphate serves as a critical nutrient for marine productivity; when sea levels shift, the flux of this nutrient changes, which in turn alters the amount of organic matter produced by marine life ^[2].

Once this organic matter dies, it sinks to the seafloor. This process of carbon burial effectively traps carbon in the earth's crust, removing it from the atmospheric cycle ^[1]. According to the research, this feedback loop has operated for tens of millions of years ^[1].

The mechanism functions as a balancing act. When atmospheric carbon levels rise and temperatures increase, the resulting changes in sea level and nutrient delivery trigger an increase in carbon burial ^[2]. This sequence reduces the concentration of greenhouse gases in the air, effectively cooling the planet back toward a baseline state ^[1].

Researchers said that the interaction between the seafloor and the open ocean is central to this stability ^[2]. The discovery provides a missing link in the understanding of how the planet avoids runaway warming or cooling over millions of years ^[1].