Produced by: Mohsin Shaikh
In a billion years, Earth’s atmosphere will lose its oxygen, suffocating most life and leaving behind a methane-rich world.
This shift mirrors pre-Great Oxidation Event Earth, where microbial life thrived without oxygen for over a billion years.
A brightening Sun will accelerate CO₂ breakdown, reducing photosynthesis and cutting off Earth’s oxygen supply.
Models predict the shift will happen quickly, with oxygen levels plummeting a million-fold in a geologic instant.
As oxygen disappears, so will the ozone layer, leaving Earth vulnerable to deadly radiation and extreme atmospheric changes.
While humans will vanish, anaerobic microbes—thriving in oxygen-free conditions—will inherit the planet.
The process will be unstoppable, triggered long before Earth’s oceans evaporate in two billion years.
If oxygen is temporary, telescopes searching for life may need new biosignatures, as alien worlds could lack oxygen entirely.
Oxygen-based life is just a brief phase in Earth’s history—our planet’s final act belongs to methane-loving organisms.