Adapted by:
Matías S. Zavia
WriterAerospace and energy industries journalist at Xataka.
Karen Alfaro
WriterCommunications professional with a decade of experience as a copywriter, proofreader, and editor. As a travel and science journalist, I've collaborated with several print and digital outlets around the world. I'm passionate about culture, music, food, history, and innovative technologies.
You can breathe easily—and so can your grandchildren’s grandchildren. But the oxygen that sustains complex life on Earth won’t last forever. Scientists estimate that Earth’s oxygen-rich atmosphere has about 1 billion years left, and the change that follows will be dramatic.
Earth will lose oxygen fast. A new study published in Nature Geoscience outlines the timeline. After running more than 400,000 simulations of the planet’s geological and biological evolution, Japanese and U.S. researchers concluded that Earth would undergo rapid deoxygenation, returning to a state similar to the Archean era, about 2.5 billion years ago.
What the sun gives, the sun takes away. Until recently, scientists believed Earth’s biosphere had about 2 billion years before global warming, caused by increased solar energy, would evaporate the oceans. But the new model paints a different picture.
According to the researchers, rising solar radiation will accelerate the carbonate and silicate cycles, which will drive down carbon dioxide levels. With less carbon dioxide available, photosynthetic organisms like plants—the main source of atmospheric oxygen—will die off. This will cause oxygen levels to plummet.
Only anaerobic life will survive. When oxygen drops to just a millionth of current levels, complex life forms will disappear long before the oceans boil or surface water vanishes. Organisms that rely on oxygen metabolism won’t survive.
The model predicts this deoxygenation will begin in 1.08 billion years, give or take 140 million years. By that time, Earth’s atmosphere will look radically different: high methane, low carbon dioxide, and no ozone layer. The planet will likely host only anaerobic life forms.
Why it matters. While this won’t affect anyone alive today—or in the distant future—it holds major implications for astrobiology. The study, funded by NASA’s Nexus for Exoplanet System Science project, shows that an oxygen-rich atmosphere doesn’t last forever on habitable planets.
Oxygen and ozone, a byproduct of oxygen, are two biosignatures scientists seek when scanning exoplanets for life. If Earth only maintains an oxygenated atmosphere for 20 to 30 percent of its lifespan, other Earth-like worlds may currently have low-oxygen or no-oxygen atmospheres. This means the search for extraterrestrial life must expand beyond oxygen-based biosignatures.
Image | Pixabay
Related | This Was the Last Time All Humans Were on Earth Together
View 0 comments