Two scientists from Toho University and NASA’s Nexus for Exoplanet System Science ran computer simulations and found that Earth’s oxygen-rich atmosphere won’t last forever—it will start disappearing in about a billion years. In their study, published in Nature Geoscience, Kazumi Ozaki and Christopher Reinhard break down the details of "their simulation and what it revealed." Experts all agree on one thing: Earth won’t be home to life indefinitely. At some point, the sun will burn through its fuel and take the planet down with it. But well before that fiery finale, rising temperatures will make survival increasingly difficult. This study set out to figure out exactly when Earth will stop being a livable place for most plants and animals. Essentially, they wanted to pinpoint the moment when life runs out of breath—literally. To figure out when Earth will no longer be a good place for most living things, the scientists built a computer model that mimicked the planet’s climate, along with geological and biological processes. The biggest piece of the puzzle? The sun’s behavior over time. They then let their simulation run to see how Earth would hold up in the distant future. Spoiler alert: it doesn’t end well for oxygen-breathing creatures. The simulation predicted that in about a billion years, as the sun cranks up the heat and pours more energy onto Earth, carbon dioxide levels will start to drop. This happens because CO₂ absorbs heat and eventually breaks apart. The ozone layer wouldn’t stand a chance either—it would get fried in the process.
