• NASA and Toho University predict Earth's oxygen-rich atmosphere will last for only another billion years.
• The aging Sun will cause increased temperatures, disrupting the carbon cycle and leading to oxygen depletion.
• The loss of oxygen will likely cause the extinction of complex life, reverting the atmosphere to its early, methane-rich state.

A collaborative study by NASA and Japan's Toho University has modeled the future of Earth's atmosphere, predicting that in approximately one billion years, the planet will experience a significant decline in oxygen levels. This phenomenon is attributed to the natural aging process of the Sun, which will become hotter and more luminous. The increased solar radiation will disrupt Earth's climate systems, weaken the carbon cycle, and ultimately lead to a 'rapid deoxygenation,' making the planet uninhabitable for complex life forms. The research highlights the long-term implications of stellar evolution on planetary habitability.

• What: Earth's oxygen-rich atmosphere will undergo 'rapid deoxygenation' in approximately one billion years due to the aging Sun, disrupting climate systems and weakening the carbon cycle.
• Who: NASA scientists, researchers from Japan's University of Toho, Kazumi Ozaki (Assistant Professor at Toho University), Christopher Reinhard (Associate Professor at Georgia Institute of Technology).
• When: The decline in oxygen is predicted to begin in one billion years, with Earth's atmosphere becoming reminiscent of early Earth after this period.
• Where: The research focuses on the evolution of Earth's atmosphere and has implications for the search for life on exoplanets beyond our Solar System.

The prediction of Earth's atmospheric changes provides a long-term perspective on planetary habitability. While climate change presents a pressing short-term challenge, this research highlights the inevitable impact of stellar evolution on Earth's environment. The study also has implications for the search for extraterrestrial life, suggesting that relying solely on oxygen as a biosignature may limit the scope of potential discoveries, as planets may exist in stages where oxygen is scarce or absent. The computer models used in the study allow scientists to analyze various scenarios and provide a probabilistic estimate of Earth's future, however, inherent uncertainties exist when projecting billions of years into the future.

"The atmosphere after the great deoxygenation is characterised by an elevated methane, low-levels of CO2, and no ozone layer. The Earth system will probably be a world of anaerobic life forms,"

Research from NASA and Toho University indicates that Earth's oxygen-rich atmosphere will decline in approximately one billion years due to the aging Sun. This event will likely result in the extinction of complex life and a shift to an atmosphere similar to early Earth. While this prediction is far in the future, it provides crucial insights into planetary evolution and the search for life beyond Earth. Current focus remains on the immediate threat of climate change, which poses a more urgent risk to humanity.