Until now, we thought that the most significant wipe-out event on Earth happened in the times of dinosaurs. However, a recent study revealed that life on Earth vanished almost entirely about 2 billion years ago, due to some extreme atmospheric changes.
In subarctic Canada’s Belcher Islands, the researchers collected samples of a 2-billion-year-old mineral known as barite. According to Malcolm Hodgskiss, the study’s co-author and Ph.D. candidate from Stanford University, rocks that ancient keep chemical signatures that can help scientists estimate how the planet’s atmosphere was like.
The new study focused on the so-called “Great Oxidation Event,” something that scientists explain as follows. Billions of years ago, the Earth was filled with microorganisms. Once these microorganisms have started to photosynthesize, they produced too much oxygen in the Earth’s atmosphere. The organisms consumed all the nutrients they needed to provide more oxygen, and that triggered extreme atmospheric changes that eventually killed life on Earth almost entirely.
Life On Earth Killed 2 Billion Years Ago By Some Extreme Atmospheric Changes, And It Could Happen Again
According to the new study, between 80% and 99.5% of life on Earth died during the “Great Oxidation Event.” Malcolm Hodgskiss explained that there were too many microorganisms, so they produced too much oxygen for them to handle. “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,” added Hodgskiss.
The result of the research, as Hodgskiss said, is relevant to us even today because life on Earth could still be endangered by extreme atmospheric changes, as it happened 2 billion years ago. The scientists came up with those conclusions thanks to a model of how much CO2 and oxygen were in Earth’s atmosphere 2 billion years ago.
Malcolm Hodgskiss also warned that ocean warming already affects the number of nutrients in the oceans, which microorganisms consume. Accordingly, a new Great Oxidation Event could happen in the future, threatening life on Earth, once again.