A new study has attempted to settle the debate about the amount of oxygen in the Earth's early atmosphere. The study, published in the journal Nature Geoscience, found that the Earth's early atmosphere contained about 1% of the oxygen that is present in the atmosphere today.

This is in contrast to previous studies that had suggested that the Earth's early atmosphere may have contained as much as 10% of the oxygen that is present in the atmosphere today.

The new study used a computer model to simulate the conditions of the Earth's early atmosphere. The model took into account the amount of oxygen that was produced by photosynthesis and the amount of oxygen that was consumed by respiration and other processes.

The model found that the amount of oxygen in the Earth's early atmosphere was limited by the amount of sunlight that was available. The amount of sunlight that was available was limited by the Earth's position in the solar system and by the amount of carbon dioxide in the atmosphere.

The results of the new study suggest that the Earth's early atmosphere was not as oxygen-rich as previously thought. This has implications for our understanding of the evolution of life on Earth. It is possible that the low levels of oxygen in the early atmosphere may have limited the evolution of complex life forms.