Geology: Most life on Earth will be DELETED in a billion years due to declining oxygen levels

An extreme sinking of atmospheric oxygen levels will destroy more than a billion years of most life on Earth, a study predicted.

Researchers in Japan and the United States have modeled how our planet’s atmosphere will change in light of various biological, climatic, and geological processes.

Deoxygenation will result from the increasing flow of energy from the Sun as it illuminates, increasing surface temperatures and reducing photosynthesis.

They found that deoxygenation in about a billion years would bring the atmosphere back to an inhospitable, methane-rich composition – one reminiscent of early Earth.

This fate, they added, will take place before the arrival of so-called wet greenhouse conditions in which water will flow irreversibly from the planet’s atmosphere.

The findings suggest that atmospheric oxygen is not a permanent device of habitable planets, which has implications for our search for life in other worlds.

An extreme sinking of atmospheric oxygen levels will destroy more than a billion years of most life on Earth, a study predicted. In the picture: the decrease in oxygen predicted by the team

Before 2.4 billion years ago, the Earth’s atmosphere was rich in methane, ammonia, water vapor and neon with noble gas, but it had no free oxygen.

This was introduced in an episode that geologists call the Great Oxygenation Event, during which cyanobacteria living in the oceans began to produce significant amounts of oxygen through photosynthesis, thus radically changing the atmosphere.

This flow of oxygen is believed to have paved the way for sustained multicellular life on a large scale, although this came at a cost – the death of many anaerobic bacteria, in what is believed to have been the first mass extinction of the Earth.

The new findings suggest that in the future of the Earth, the atmosphere could turn upside down and possibly return to the world anaerobic microorganisms.

“We find that future deoxygenation is an inevitable consequence of increased solar fluxes,” the research duo wrote in their paper.

“Its precise moment is modulated by the flow of reducing power exchange between the mantle and the ocean-atmosphere-crust system.”

“Our results suggest that the planetary carbonate-silicate cycle will tend to lead to terminally limited CO2 biospheres and rapid atmospheric deoxygenation.”

Atmosphere oxygenation is commonly seen as indicative of the Earth’s current biosphere, plants, and photosynthetic activity. Therefore, logic goes, we should look for similar oxygenated worlds in our hunt for extraterrestrial life.

However, the findings suggest that – from the point of view of a hypothetical distant alien observer – the detection of atmospheric oxygen on Earth could be possible only about two to three tenths of the life of our planet.

If this is true for other planets, the researchers say, we may need to adjust our search for life elsewhere in the universe to look for additional biosignatures, those that indicate the existence of life outside the oxygen-rich period of a planet.

The full results of the study were published in the journal Nature Geoscience.

WHAT IS THE FERMI PARADOX?

The Fermi paradox wonders why, given the estimated stars of 200 billion-400 billion and at least 100 billion planets in our galaxy, there were no signs of extraterrestrial life.

The contradiction is named after its creator, the Italian physicist Enrico Fermi.

He first asked the question in 1950.

Fermi thought it was too extraordinary that a single extraterrestrial signal or engineering project had yet been detected in the universe – despite its immense immensity.

Fermi concluded that there must be a barrier that limits the growth of intelligent, self-aware, technologically advanced civilizations that colonize space.

This barrier is sometimes called the “Great Filter”.

Italian physicist Enrico Fermi conceived the so-called Paradox Fermi in the 1950s. He explores why there are no signs of extraterrestrial life, despite the 100 billion planets in our galaxy.

If the main obstacle to the colonization of other planets is not in our past, then the barrier that will stop humanity’s prospects of reaching other worlds must be in our future, scientists have theorized.

Professor Brian Cox believes that the advances in science and engineering required by a civilization to begin conquering the stars eventually lead to its destruction.

He said: ‘One solution to the Fermi paradox is that it is not possible to lead a world that has the power to destroy itself and that needs global collaborative solutions to prevent this.

“The development of science and engineering may inevitably go beyond the development of political expertise, leading to disaster.”

Other possible explanations for the Fermi Paradox include that no other intelligent species have appeared in the universe, intelligent alien species are there – but they do not have the technology to communicate with Earth.

Some believe that the distances between intelligent civilizations are too great to allow any kind of two-way communication.

If two worlds are separated by several thousand light-years, it is possible that one or both civilizations will disappear before a dialogue can be established.

The so-called zoo hypothesis holds that intelligent alien life is there, but deliberately avoids any contact with life on Earth to allow for its natural evolution.