The very distant future, about a billion years from now, scientists say that Earth’s atmosphere will contain very little oxygen. This would make the planet uninhabitable for a complex aerial life. Today, our atmosphere is composed of about 21 percent oxygen, and this oxygen-rich nature makes it ideal for large and complex organisms like humans.
In the distant past of Earth, Universe It has much lower oxygen levels, and scientists believe that similarly low oxygen levels are possible in the far future. Researchers Kazumi Ozaki of Toho University and Chris Reinhard of the Georgia Institute of Technology have modeled the Earth’s climate, biological, and geological systems to see how conditions will change in the future. Their research found that Earth’s atmosphere will have high levels of oxygen over the next billion years before returning dramatically to low levels similar to what existed before an event known as the Great Oxidation Event that occurred about 2.4 billion years ago.
The researchers say they have found that our planet’s oxygen-rich atmosphere is not a permanent feature. One of the main reasons they expect a change in oxygen levels is because as the sun ages, it gets hotter and releases more energy. This is expected to lead to a decrease in the amount of carbon dioxide in the atmosphere as it absorbs heat and decomposes.
Calculations estimate that within a billion years, the level of carbon dioxide on Earth will become so low that organisms such as plants will not be able to survive to produce oxygen. The mass extinction of photosynthetic organisms will be the primary driver of the massive oxygen reduction on the planet.
Reinhard thinks the drop in oxygen would be about a million times less oxygen-rich on the planet than it is today. At the same time, methane levels would increase dramatically, reaching about 10,000 times the amount of methane in the atmosphere today. The change from oxygen-rich to oxygen-poor is thought to occur over a period of about 10,000 years.