New findings suggest earlier oxygenation of Earth's oceans and atmosphere
Scientists have uncovered new evidence that the rise of oxygen in Earth's atmosphere, known as the Great Oxidation Event, began earlier than previously thought, around 2.5 billion years ago, leading to significant changes in the planet's environment and the evolution of complex life. Using advanced geochemical techniques on ancient rock cores from South Africa, researchers traced nitrogen isotope ratios to reconstruct the timeline of oxygenation, revealing a gradual process that profoundly shaped Earth's biosphere.