A new study with a Canadian connection reveals that all life on earth was nearly obliterated two billion years ago.
Researchers came to this conclusion after testing barite, a mineral found in Belcher Islands, in the southeast part of Hudson Bay, which is part of Nunavut.
The rocks were helpful for researchers as they “lock in chemical signatures” needed to understand what the atmosphere was like when they first formed, co-lead author and Stanford University Ph.D. candidate Malcolm Hodgskiss told CNN.
Ultimately the study determined that there is such a thing as too much oxygen, by examining the circumstances surrounding the “Great Oxidation Event.”
Billions of years ago, long before dinosaurs, the only creatures that were able to survive on Earth were micro-organisms. When they photosynthesized, they changed the chemical composition of the air, leading to a surplus of oxygen that couldn’t be sustained.
The Earth’s atmosphere was ultimately sent askew, as the micro-organisms drained all the nutrients they needed in order to create oxygen. In turn, the biosphere - also known as life on Earth - experienced an “enormous drop,” and scientists only recently began to understand just how enormous it was.
According to their findings, anywhere between 80 to 99.5 per cent of organisms at the time were abolished, since there were too many of them creating too much oxygen.
"Even our most conservative estimates would exceed estimates for the amount of life that died off during the extinction of the dinosaurs approximately 65 million years ago," Hodgskiss told CNN.
Since the planet is still vulnerable to atmospheric changes, these ancient findings are pertinent to the current day. Warming oceans affect nutrient levels and runoff in oceans interferes with underwater ecosystems. This in turn threatens photosynthesizing organisms that supply more than half of the oxygen in the planet’s atmosphere.
Editor’s note: An earlier version of this article said all human life was obliterated two billion years ago. This has been corrected.