Scientists predict that in about 1 billion years, Earth’s atmosphere will undergo a dramatic shift, losing nearly all its oxygen and becoming inhospitable for most life forms. This comes as new research suggests that the current oxygen-rich environment is only temporary.
About 2.4 billion years ago, the Great Oxidation Event (GOE) increased oxygen levels, paving the way for complex life. However, researchers from Toho University in Japan and the Georgia Institute of Technology modeled Earth’s atmospheric evolution, finding that a decline in carbon dioxide will lead to less oxygen production.
As the Sun brightens over time, solar radiation will break down CO2, fueling photosynthesis. This decline will eventually lead to conditions similar to those before the GOE, dominated by methane and low oxygen levels. Oxygen levels are expected to drop by a factor of a million, leaving most life forms unable to survive.
This transformation is predicted to occur quickly in geological terms, with only anaerobic microbes able to persist without an ozone layer. The findings raise questions about how scientists search for extraterrestrial life, highlighting the need for alternative biosignatures beyond oxygen alone.
The research also underscores the temporary nature of Earth’s habitability, reinforcing that our planet will not always be suitable for life. Rising solar radiation and ocean evaporation will make survival increasingly difficult long before the atmosphere changes.
Source: https://dailygalaxy.com/2025/02/earth-oxygen-is-disappearing