For decades, scientists have debated when measurable oxygen levels first appeared in Earth’s atmosphere. The idea of the Great Oxygenation Event has evolved over the past century, and it is believed that oxygen levels began to rise over 2 billion years ago, paving the way for the emergence of complex cells, animals, and eventually humans. However, a new study has just revealed that oxygen on Earth could be holding up. Read to find out all about it.
In a research paper published under Persia Digest, a team of astronomers revealed the time remaining until Earth’s oxygen supply ended. According to estimates by a group of scientists, oxygen is expected to last only another billion years on our planet.
The observation of early oxygen was made by some research groups to support earlier findings that microscopic cyanobacteria — early innovators in photosynthesis — pumped oxygen into the ancient atmosphere, but other Earth processes kept oxygen levels low.
Previous studies related to the cessation of oxygen on Earth
In 2007, two parallel studies found evidence of just such a whiff of oxygen based on samples from the 2.5 billion-year-old Mount McRae Shale, part of a heavily studied 2004 drill core collected in Western Australia by the NASA Astrobiology Drilling Program. The 2007 studies were based on evidence of oxidation and reduction of molybdenum and sulfur, two elements commonly used to test the presence of oxygen in the air, as it cannot be measured directly in rock. The findings raised fundamental questions about the early evolution of life on Earth.