Overview

• A Science Advances paper reports a 0.72 correlation over 540 million years between the virtual geomagnetic axial dipole moment and atmospheric oxygen levels.
• Peak intensities of both the geomagnetic field and atmospheric oxygen occurred between 330 million and 220 million years ago, aligning with major geological and biological transitions.
• Analysis drew on two independent datasets: paleomagnetic records preserved in ancient rocks and geochemical proxies such as fossil charcoal and ocean anoxia indicators.
• The underlying mechanism remains unresolved, with hypotheses ranging from magnetic shielding of atmospheric gases to common drivers in tectonic-driven mantle convection.
• The findings provide a new criterion for assessing planetary habitability by suggesting that exoplanets with strong magnetic fields may sustain higher oxygen levels conducive to complex life.