We exist as long as there is oxygen in the air. Oxygen, which comprises 21 percent of Earth’s atmosphere, plays a vital role in the survival of numerous species. But these dimensions were not always the same. When the Earth was formed 4.5 billion years ago, the situation was completely different. The influence of carbon dioxide, methane and water vapor on Earth’s atmosphere was much greater then. Now scientists are predicting that in the future the Earth’s atmosphere will come to a place where oxygen levels are very low.
A study published in Nature in 2021 also hinted at that period. That time, it was said, was still a billion years away. But when that great change comes, it will spread like wildfire everywhere. According to the study, this shift would take Earth to a point known as the Great Oxidation Event (GOE) about 2.4 billion years ago.
Now the question may arise, why the fuss again about the research of 2021? One reason. Scientists have been searching for habitable planets outside the solar system for a long time. And the pace of that search has increased recently. Atmospheric oxygen is unlikely to remain a permanent feature of future habitable worlds, the report notes.
“Oxygen rates are dropping dramatically,” Chris Reinhardt of the Georgia Institute of Technology told New Scientist. There will come a time when we may be talking about a million times less oxygen than today.”
The scientists who predicted the final scenario, said in the study, “The model projected that, with atmospheric deoxygenation, atmospheric O2 would have fallen dramatically to Archaean Earth levels. Deoxygenation will most likely begin before the onset of Earth’s moist greenhouse conditions and before large-scale losses of surface water from the climate system and atmosphere occur.”
Researchers have developed detailed models of Earth’s atmosphere by analyzing changes in the sun’s brightness and corresponding drops in carbon dioxide levels. Now less carbon dioxide means lower rates of photosynthetic organisms like plants. As a result, the oxygen level in the air will literally drop to rock bottom.