According to a new study, in about a billion years, life on Earth will be wiped out because our atmosphere will contain barely any oxygen that humans, animals, and plants all need in order to survive.
Even though our atmosphere today contains approximately 21% oxygen, when our planet first formed, there wasn’t as much oxygen and experts believe that the same thing will happen again in a billion years.
In order to come to this conclusion, Kazumi Ozaki from Toho University in Funabashi, Japan, and Chris Reinhard from the Georgia Institute of Technology in Atlanta created a model of our planet’s biological, geological, and climatic systems to predict how our atmosphere will change in the very distant future. They concluded that there will be lots of oxygen for the next billion years before levels start dropping dramatically.
The reasoning behind this is because as the sun gets older, it gets hotter and releases a lot more energy which will lower the carbon dioxide levels in the atmosphere. This is actually very bad news as carbon dioxide absorbs the heat from our sun.
Ozaki and Reinhard went into further details by stating that the carbon dioxide levels will be so low that plants and other photosynthesizing organisms won’t be able to produce oxygen; therefore, rending them unable to survive on our planet and causing them to become extinct. “The drop in oxygen is very, very extreme – we’re talking around a million times less oxygen than there is today,” Reinhard explained.
With the drop in oxygen comes an increase in methane – as much as 10,000 times what we currently have in our atmosphere. Once these changes begin happening, the atmosphere could completely lose all of its oxygen within just 10,000 years.
As for what will happen after the atmosphere loses its oxygen, Reinhard explained that there will be nothing left except for microorganisms. “A world where many of the anaerobic and primitive bacteria are currently hiding in the shadows will, again, take over.” There will be no more life on land or in the water. Furthermore, the ozone layer will be gone which will subject our planet and our oceans to very high amounts of ultraviolet light and exceptional solar heat.
This information will also help experts who are looking for possible signs of life on other planets. Natalie Allen from Johns Hopkins University in Maryland explained, “Oxygen, in its many forms, is a very important biosignature since it is intertwined with life so fully on Earth.” However, some possibly habitable planets may not have permanent oxygen. Kevin Ortiz Ceballos at the University of Puerto Rico detailed this further, “It suggests that even for planets around other stars that are very similar to Earth, large amounts of oxygen may not be detected in their atmosphere, even if they can support, or have supported, complex life,” adding that if oxygen isn’t detectable, it doesn’t necessarily mean that they don’t contain some type of life.
Ozaki and Reinhard’s study was published in Nature Geoscience where it can be read in full.