Scientists Warn Earth’s Oxygen Levels Could Drop a Million-Fold, Threatening Life on Our Planet
Oxygen is paramount for the survival of many beings on Earth. Therefore, when a team of researchers found that oxygen levels on Earth are in danger of dropping by a millionfold, they were evidently concerned, stated Daily Galaxy. Findings regarding this development were published in Nature Geoscience.
The team's objective was to determine what the Earth's atmosphere would look like in the future. The analysis revealed that in the next billion years, there would be a dramatic decline in oxygen levels. If the assertion turns out to be true, then the Earth's conditions will be similar to how it was before the Great Oxidation Event around 2.4 billion years ago. For the examination, the researchers created detailed models depicting Earth's geochemical cycles and how they are impacted by the Sun’s increasing brightness.
The models showcase that the reduction of atmospheric O2 levels will possibly happen before the inception of moist greenhouse conditions and loss of surface water in the atmosphere, according to Science Alert. If the oxygen levels drop down millionfold, then it will be the end of humans and other respiration-dependent life forms on Earth. The study was conducted as a part of the NASA NExSS (Nexus for Exoplanet System Science) project. The objective of this project is to determine the habitability of other planets in space. The study showcases that oxygen is not present forever in the atmosphere of habitable planets like Earth. Hence, experts should possibly look for biosignatures other than oxygen when determining a planet's habitability.
The models in the examination also considered how carbon dioxide levels will come down in the future due to increasing heat. Researchers claimed that when carbon dioxide starts reducing, so will the population of photosynthesizing organisms such as plants. Since these organisms create oxygen, the phenomenon will hamper the production of new oxygen in the atmosphere. In the past, researchers speculated that increasing radiation from the sun would kill humans around two billion years from now. This study, based on around 400,000 simulations, claims that oxygen reduction would deliver the fatal blow first, just a billion years from now.
Earth scientist Chris Reinhard, from the Georgia Institute of Technology, asserts that the drop would be very extreme, "around a million times less oxygen than there is today." The study estimates that oxygen would remain a part of Earth's atmosphere for only around 20 to 30 percent of its lifespan. However, certain microbial life forms will possibly continue to exist even after humans and other oxygen-dependent beings vanish. Environmental scientist Kazumi Ozaki from Toho University in Japan claimed that after the great deoxygenation, the planet would have more methane, no ozone layer, and a low quantity of CO2. This kind of system would be apt for anaerobic life forms, the expert added.
The study further claimed that the drop in oxygen would be dramatic, according to New Scientist. This implies that the atmosphere would exhibit high levels of oxygen, and then it would suddenly drop. Along with a decrease in oxygen, there will also be a coinciding increase in methane, which will possibly be 10,000 times more than the present levels. In such a scenario, terrestrial as well as aquatic life will cease, and the planet will be taken over by anaerobic and primitive bacteria.