Research groups such as Toho University have compiled simulation results that the concentration of oxygen in the atmosphere of the earth after about 1 billion years will drop to less than 1 / 100,000 of the present, and the earth in the distant future was ancient when oxygen was thin. It is said that there is a possibility that the environment will be similar to that of the times.
The earth, which was born 4.6 billion years ago, is covered with an atmosphere of carbon dioxide and nitrogen, and it is said that the concentration of oxygen increased as the microorganisms and plants that were born soon started photosynthesis, and the present earth was created. ..
Research groups such as Professor Kazumi Ozaki of Toho University have simulated how the sun's supposed increase in brightness affects the earth in the long run.
As a result, as the temperature rises over hundreds of millions of years, carbon dioxide is taken up by weathered rocks and becomes difficult to use, photosynthesis of plants decreases, and the concentration of oxygen in the atmosphere decreases. is.
Then, about 1 billion years later, when the ozone layer almost disappears and the amount of ultraviolet rays reaching the surface of the earth increases, a chemical reaction occurs in the atmosphere, oxygen is consumed, and it drops sharply to less than 1 / 100,000 of the current level. doing.
The research group believes that the environment will be similar to that of the Earth about 2.5 billion years ago when oxygen was thin, and that oxygen-free organisms will flourish on the surface of the earth.
Lecturer Ozaki says, "The environment of stars will change drastically over a very long period of time, and it will be a useful achievement when searching for stars similar to the Earth in the wide universe."