Scientists warn that most of Earth’s life will be wiped out in a billion years due to an extreme drop in oxygen levels
- Researchers in Japan and the United States modeled the future of the Earth’s atmosphere
- Increased sunlight will affect surface temperatures and photosynthesis
- This will cause rapid atmospheric deoxygenation after a billion years
- The finding has implications for how we search for habitable planets elsewhere
According to a study, an extreme drop in atmospheric oxygen levels will end in a billion years with most of life on Earth.
Researchers from Japan and the United States 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 shines, increasing surface temperatures and reducing photosynthesis.
They discovered that deoxygenation in a billion years would return the atmosphere to an inhospitable, methane-rich composition, reminiscent of Earth’s early years.
This fate, they added, will occur before the arrival of the so-called humid greenhouse conditions in which water will irreversibly leave 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 advance in atmospheric oxygen levels will end in a billion years with the disappearance of most life on Earth, a study has predicted. In the picture: the oxygen drop that the team predicted
Before 2.4 billion years ago, the Earth’s atmosphere was rich in methane, ammonia, water vapor and neon 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 credited with paving the way for supporting large-scale multicellular life, although it also came at a cost: the death of many anaerobic bacteria, in what is believed to have been the first mass extinction of the Earth.
New findings suggest that in the future of the Earth, the atmosphere could swing backwards and possibly return the world to anaerobic microorganisms.
“We find that future deoxygenation is an inevitable consequence of increased solar fluxes,” the research duo wrote in their article.
“Its precise timing is modulated by the reducing power exchange flow between the mantle and the ocean-atmosphere-crust system.”
“Our results suggest that the carbonate-silicate planetary cycle will tend to lead to limited terminal CO2 biospheres and rapid atmospheric deoxygenation.”
Atmosphere oxygenation is commonly seen as indicative of the Earth’s current biosphere, plants, and photosynthetic activity. Therefore, logically, we should look for similar oxygenated worlds in our search 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 only be possible for about two-thirds of the life of our planet.
If this is also true for other planets, the researchers argue, we may need to adjust our search for life elsewhere in the universe to look for additional biosignatures, indicating that life persists outside the oxygen-rich period. of a planet.
The full findings of the study were published in the journal Nature Geoscience.
WHAT IS THE FERMI PARADOX?
Fermi’s paradox wonders why, given the estimated 200,000 and 400 billion stars and at least 100 billion planets in our galaxy, there have been no signs of alien life.
The contradiction is named after its creator, the Italian physicist Enrico Fermi.
He asked the first question in 1950.
Fermi believed 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 limiting the rise of intelligent, self-aware, and technologically advanced space colonizing civilizations.
This barrier is sometimes known as the “Great Filter”.
The Italian physicist Enrico Fermi devised the so-called Fermi paradox in the 1950s. Explore why there are no signs of alien life, despite the 100 billion planets in our galaxy
Scientists have theorized that 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 should be in our future. .
Professor Brian Cox believes that the advances in science and engineering required by a civilization to begin conquering stars eventually lead to their destruction.
He said: ‘One solution to Fermi’s paradox is that it is not possible to lead a world that has the power to destroy itself and needs global collaborative solutions to prevent it.
“The growth of science and engineering may inevitably outweigh the development of political experience, leading to disaster.”
Other possible explanations for Fermi’s paradox include that no other intelligent species has emerged in the universe, there are intelligent alien species, 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 for one civilization or both to become extinct before a dialogue can be established.
The so-called Zoo hypothesis states that there is intelligent alien life, but deliberately avoids any contact with life on Earth to allow for its natural evolution.