Oxygen, the unseen component, permeates every aspect of life on Earth and shapes our entire being. This vital gas, which makes up 21% of the Earth's atmosphere, is essential to the existence of many species. However, things weren't always like this. Circa 4.5 billion years ago, the world was formed under quite different conditions. The main components of the Earth's atmosphere were carbon dioxide, methane, and water vapour. Furthermore, scientists have projected that Earth's atmosphere will eventually return to a low oxygen content.

The situation when it occurs is described in a paper that was published in Nature in 2021. Although it will take a billion years for that to happen, it will happen rather quickly. Earth’s Core is Leaking? New Study on Discovery of Traces of Helium Reveals Shocking Facts About Our Planet.

According to the study, the shift will return Earth to a condition like that of the planet prior to the Great Oxidation Event (GOE), which occurred around 2.4 billion years ago.  Researchers are looking for habitable planets outside of our solar system, which is why the research is making headlines once again. It states that generally speaking, inhabited worlds are unlikely to have atmospheric oxygen as a permanent feature.

"There is a very sharp decrease in oxygen. We're talking about a million times less oxygen than there is today", according to Chris Reinhard of the Georgia Institute of Technology. According to the scientists who predicted the doomsday scenario in the research, the model predicts that deoxygenation of the atmosphere, with atmospheric O2 dropping sharply to levels reminiscent of the Archaean Earth, will most likely be triggered before the onset of moist greenhouse conditions in Earth's climate system and before the extensive loss of surface water from the atmosphere. NASA’s James Webb Space Telescope Will Study Two Earth-Like Planets.

Scientists modelled the Earth's atmosphere in great detail, examining variations in solar brightness and the resulting decrease in carbon dioxide concentrations. Reduced carbon dioxide levels lead to a decrease in photosynthesizing organisms, such as plants, which in turn produce less oxygen.

(The above story first appeared on LatestLY on Nov 18, 2023 05:57 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).