Earth’s atmosphere wasn’t always rich in oxygen, and scientific predictions don’t always stay that way: Over time, air that’s low in oxygen and rich in methane will return.
Atmospheric oxygen appeared 2.4 billion years ago in a rapid process called the Great Oxygenation Event. The disappearance of oxygen could cause the planet to return to a state similar to the previous period.
According to our model, the oxygen content in the atmosphere during deoxygenation drops to the level usual in antiquity, and this occurs already before the greenhouse-like warming and the disappearance of surface waters.
– Researchers wrote.
The research examined a detailed model of the Earth along with the biosphere and changes in the brightness of the sun. It was previously assumed that the increasingly intense radiation from the aging sun will evaporate the Earth’s oceans in about two billion years – predictions based on four hundred thousand simulations predicted that Earth life will disappear much earlier with the depletion of oxygen.
The drop in oxygen levels is very severe. We’re talking about one in a million of today’s level
Said Chris Reinhard, the researcher at Georgia Tech who created the model.
According to Reinhard and his colleague Kazumi Ozaki, only 20 to 30 percent of their history is characterized by an atmosphere rich in oxygen. This recognition may be of great importance in the search for habitable (or formerly habitable) exoplanets.
As the oxygen content rises, carbon dioxide decreases, methane levels increase, and the ozone layer disappears. From here, Earth becomes a world of anaerobic life forms
Ozaki noted.
The major deoxygenation process that would occur in a billion years would be relatively rapid. When that happens, the sequence of events will mean the end of life on Earth, including humanity, although if all goes well, people will have moved to other planets by then.
