In the future, the land may lose oxygen - and much earlier than expected. According to a new study, the atmosphere rich in oxygen, which makes there a difficult life, will disappear in a billion years. This will make the planet not suitable for most known life forms.
About it writes BBC Sky at Night Magazine , referring to the joint work of scientists from Japan and the US.
The team of researchers headed by Associate Professor Thoho Kazaki Odzaki and Christopher Reinhard from Georgia's technology institute created a complex computer model for analyzing climatic and biochemical processes on the planet. The purpose was to find out when the Earth's atmosphere ceased to maintain a high level of oxygen.
According to the results of more than 400 thousand models, scientists have come to the conclusion: after about 1 billion years there will be a "rapid deoxygenation" - a sharp decrease in the level of oxygen in the atmosphere. The Earth will return to a state similar to the fact that existed to a "great oxidative event", which occurred 2.5 billion years ago. Then, as a result of the activity of microorganisms, free oxygen appeared in the air, which eventually enabled to evolve a difficult life.
After loss of oxygen, the atmosphere will become rich in methane, the level of carbon dioxide will fall, and the ozone layer will completely disappear. The planet will no longer be able to protect life from harmful ultraviolet light, and will dominate anaerobic - that is, those that do not need oxygen - life forms.
The study has a broader astronomical context. Today, scientists in search of extraterrestrial life focus on "biosign" - in particular, the presence of oxygen in the planet's atmosphere. But the authors of the new work indicate that such a strategy may be false. Oxygen atmosphere is not a constant characteristic even for the planet with an active biosphere. The earth had oxygen only for about a third of its existence - therefore, there is a risk that we simply do not recognize potentially inhabited worlds.
"In order to increase the chances of identifying life outside the Earth, we need to consider those planets whose atmosphere contains little oxygen or does not have it at all," the researchers emphasize.
However, it is more important to humanity: the oxygen pillow we rely on is not eternal.
