Right now, life is booming for the rich Oxygen Our planet, but Earth wasn’t always like this – and scientists predict that in the future the atmosphere will revert to a methane-rich, oxygen-poor atmosphere.
This probably won’t happen in the next billion years or so. But when change comes, it will be very fast, according to research published in 2021.
This change will return the planet to something similar to the state it was in before what is known as The great oxidation event (GOE) about 2.4 billion years ago.
In addition, the researchers behind the study say that atmospheric oxygen is unlikely to be a permanent feature of generally habitable worlds in the future, which has implications for our efforts to detect signs of life farther out in the universe. “The model predicts a lack of oxygen in the atmosphere, with a sharp decline in atmospheric O2 to levels reminiscent of ancient land“This likely occurred before the onset of wet global warming conditions in Earth’s climate system and before large-scale loss of surface water from the atmosphere,” the researchers explained in a job they.
At this point it will be the end of the road for humans and most other life forms that rely on oxygen to survive, so let’s hope we find a way. We leave the planet Sometime within the next billion years.
To reach their conclusions, the researchers conducted detailed models of Earth’s biosphere, taking into account changes in the sun’s brightness and the corresponding decrease in carbon dioxide levels as the gas breaks down due to rising heat levels. A decrease in carbon dioxide means a decrease in photosynthetic organisms such as plants, which can lead to a decrease in oxygen.
Scientists had previously predicted that increased radiation from the sun would erase ocean water from the face of our planet inside About 2 billion years agoBut this model here – based on an average of (roughly) 400,000 simulations – says that oxygen depletion will kill life first.
“The drop in oxygen is very severe,” he said. new world Geologist Chris Reinhard, of the Georgia Institute of Technology; “We’re talking about a million times less oxygen than there is today.”
What makes the study particularly relevant today is our search for habitable planets outside the solar system. Increasingly Powerful telescopes They are mandated and scientists want to be able to know what to look for in the volumes of data these tools collect.
Researchers say it’s possible that we need to look for biosignals other than oxygen to have the best chance of detecting life. Their studies are part of the programme Nexus NASA’s Nexus for Exoplanet System Science, which researches the habitability of other planets.
According to calculations by Reinhard and ecologist Kazumi Ozaki, of Japan’s Toho University, Earth’s oxygen-rich habitable history could eventually end in a state in which oxygen would be sufficient for only 20 to 30% of the planet’s total lifespan — and microbial life would persist. . To live long after we are gone.
“The post-deoxygenation atmosphere is characterized by increased methane and low and absent carbon dioxide levels Ozone zone“, He said Ozaki.
“The Earth system is likely a world of anaerobic life forms.”
The research was published in Natural earth sciences. A previous version of this article was published in March 2021.
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