According to scientists, the oxygen currently in the Earth’s atmosphere will disappear in a billion years. This image of the Earth’s atmosphere was extracted from the International Space Station on February 26, 2021. Image via NASA.
Breathe deeply. The air that expands the chest is mainly nitrogen and oxygen, the main components of our atmosphere. Oxygen exists in our atmosphere through the exhalation of plants, through the process of photosynthesis. A study published in March 2021 shows that from a billion years on, as the sun heats up, plants will die and take away the oxygen from our atmosphere that humans and animals need to to breathe.
Kazumi Ozaki of the University of Tokyo and Chris Reinhard of Georgia Tech modeled the Earth’s climatic, biological, and geological systems to fine-tune scientists ’understanding of the Earth’s future atmospheric conditions. They undertook the research as part of a NASA program called NExSS to explore and evaluate the habitability of exoplanets. His study was published on March 1, 2021 in the peer-reviewed journal Geoscience of nature.
The Earth’s current atmosphere is made up of 78% nitrogen, 21% oxygen, 0.9% argon and 0.1% other gases, including carbon dioxide, methane. , water vapor and neon. The Earth has not always had such a high percentage of oxygen in its atmosphere. During the first 2 billion years of the Earth, there was no oxygen in the atmosphere. Low oxygen levels first appeared when cyanobacteria, also called blue-green algae, began to release oxygen as a byproduct of photosynthesis. Then, about 2.4 billion years ago, the Earth suffered the great event of oxidation. At this point, either through a loosening of volcanic degassing or an evolutionary innovation that made cyanobacteria more successful, oxygen began to accumulate in larger amounts in the atmosphere, killing some bacteria but allowing the more complex life (us!) to evolve.
This oxygen utopia in which we currently live, where plants produce oxygen for humans and animals to breathe, is only a temporary condition on Earth. As Ozaki said:
We find that the Earth’s oxygenated atmosphere will not be a permanent feature.
Kazumi Ozaki, of the University of Tokyo, lead author of the paper investigating the future of oxygen on Earth. Image via NASA.
As the solar system continues its life cycle, the aging sun will begin to heat up. The increase in solar production will further heat the atmosphere and carbon dioxide will react to the increase in temperature as it decomposes. Carbon dioxide levels will decrease until photosynthesizing organisms (which depend on administering carbon dioxide for living, in the same way we rely on oxygen for living) can no longer survive, removing the oxygen source from the Earth. (Read about how scientists believe that phytoplankton provide between 50 and 85% of the oxygen in the Earth’s atmosphere.) So when plants die from a lack of carbon dioxide, it’s not just a loss of carbon dioxide. the food chain, but basically a loss of air they produce and the air we breathe.
Although the end of oxygen is still a billion years away, when depletion begins to take hold, it will occur fairly quickly, after about 10,000 years. Reinhard explained the seriousness of the change:
The oxygen drop is very, very extreme; we talk about a million times less oxygen than there is today.
Chris Reinhard of Georgia Tech, one of the lead authors who investigated the future amount of oxygen in the Earth’s atmosphere. Image using NExSS.
The future deoxygenation event will coincide with an increase in methane, until methane levels are approximately 10,000 times higher than those that currently exist in the atmosphere. These changes will occur too quickly to adapt to the biosphere. The ozone layer, made of oxygen, will disappear and ultraviolet light and heat will help extinguish both terrestrial and aquatic life. All microbes, except microbes, will face extermination. Reinhard said:
A world where many of the anaerobic and primitive bacteria currently hiding in the shadows will take over again.
As in the beginning, when life on Earth was in microbial form before reaching the variety we see today, the future will also look very much like the past, as if the clock were ticking back and complex life forms were extingissin. except tiny cell colonies.
All plant and animal life on Earth needs oxygen to survive. Within a billion years, the Earth’s oxygen will be depleted in a span of about 10,000 years, causing global extinction for all but microbes. Image using Dikaseva / Unsplash.
Studying the past and future of the Earth is a gateway to understanding the favorable conditions for life on other planets. The presence of oxygen is an important factor in determining whether life can exist on a planet. As we see with Earth, however, a planet that has no oxygen signature may be able to withstand life in the future or in the past.
So while finding a planet with oxygen would be an exciting step toward life, no finding oxygen should not rule out the possibility that a planet always he had life.
In short: from a billion years, scientists say, as the sun heats up, the warmer atmosphere will break down carbon dioxide and kill plant life, which in turn will shut down the source of ‘oxygen of the Earth.
Source: The future life of the Earth’s oxygenated atmosphere
Via New Scientist
