If the current level of oxygen on Earth were to dwindle, life would be lost forever. Now, life on our oxygen-rich planet is smooth. But this was not the case at the time of the earth's origin. The Earth's atmosphere was low in oxygen and rich in methane and other gases. That is, before life began to flourish on earth. The dust and gases of the universe merge and rotate around, condensing into one another by the force of gravity. Numerous volcanoes have formed on the rotating globe. These have been exploding for many years. The lava that came out spread all over the earth's crust. Thus the mountains were formed. In addition, volcanic eruptions spread ash and heat into the atmosphere, causing months of torrential rain. Thus the oceans were formed. All this happened long before the origin of life.
But according to the laws of the universe, our earth cannot fail to return to its former state. This means that over time, the level of oxygen will decrease and life on Earth will become impossible. Do not be afraid. This is not something that happens today or tomorrow. This will take years. This change will bring the planet back to what was known as the Great Oxidation Event (GOE) about 2.4 billion years ago.
Recent research suggests that atmospheric oxygen may not be a permanent feature of habitable spheres in general. This has repercussions for our efforts to find more signs of life in the universe.
According to the researchers' model projects, deoxidation of the atmosphere and a sharp decrease in oxygen levels in the atmosphere, reminiscent of the Archean Earth era, are most likely to occur before the onset of humid greenhouse conditions and extensive loss of surface water in the Earth's climate.
If such a situation arises, the very existence of human beings and other living beings will be in danger.
To reach the conclusions, the researchers created detailed models of the Earth's biosphere and studied changes in the sun's light intensity and the corresponding decrease in carbon dioxide levels. Researchers have found that increased radiation from the sun significantly reduces the amount of carbon dioxide. Decreased levels of carbon dioxide can disrupt the photosynthesis process in the earth's vegetation and lead to a drastic reduction in oxygen availability.
Scientists had previously predicted that increased radiation from the sun would dry up seawater in about 2 billion years. A new study has found that a lack of oxygen could wipe life off the face of the earth forever.
Today's study is relevant to our search for habitable planets outside the Solar System.
According to Reinhardt and Kazumi Osaki, an environmental scientist from the University of Toho in Japan, Earth's oxygen-rich habitable history is only 20-30 percent of the planet's total lifespan. After the destruction of living things, including humans, only microorganisms will remain on earth.
Only high levels of methane, low levels of oxygen and other gases remain in the atmosphere after deoxidation. The ozone layer will be completely eliminated, Osaki said. At that time, the Earth will probably be a sphere of anaerobic microorganisms. "
Source: Nature Geoscience 2021