– Earth’s transition to permanently hosting an oxygenated atmosphere is a stoppage process that takes 100 million years longer than previously believed, according to a new study.
When Earth first formed 4.5 billion years ago, the atmosphere contained almost no oxygen. But 2.43 billion years ago, something happened. That is, oxygen levels began to rise, then fall, accompanied by major changes to the climate, including some glaciations that may have covered the entire world in ice.
Chemical markers locked in the rocks formed during this era suggest that as of 2.32 billion years ago, oxygen was a permanent feature of the planet’s atmosphere.
Also read: The new Toyota Harrier greets ASEAN, what’s the difference with the Japanese version?
But a new study investigating a period after 2.32 billion years ago finds oxygen levels were still spinning up to 2.22 billion years ago, when the planet finally reached a permanent tipping point. The new research, published in the journal Nature on March 29, extends the duration of what scientists call the Great Oxidation Event to 100 million years. It can also confirm a link between oxygenation and massive climate change.
“We are only now starting to see the complexity of this event,” said study co-author Andrey Bekker, a geologist at the University of California, Riverside, as quoted by Live Science.
The oxygen created in the Great Oxidation Event is made by marine cyanobacteria, a type of bacteria that produce energy through photosynthesis. The main byproduct of photosynthesis is oxygen, and the early cyanobacteria eventually produced enough oxygen to reshape the face of the planet forever.