• Question: Will the oxygen in earth ever run out so we die?

    Asked by Ciara to Chris, Josh, Rebecca, Rob, Susan on 22 Jun 2015.
    • Photo: Rebecca Dewey

      Rebecca Dewey answered on 22 Jun 2015:

      It could in theory – but we have lots of ways of making more oxygen (the best one being trees!). All green plants use carbon dioxide and produce oxygen. So as long as we have trees, we shouldn’t run out of oxygen.

    • Photo: Susan Cartwright

      Susan Cartwright answered on 22 Jun 2015:

      Only if all the plants (and the single-celled photosynthetic organisms too) die out. Oxygen is not stable in the atmosphere – it is continually resupplied by plants.

      I don’t think oxygen starvation is the extinction mechanism of choice, as regards atmosphere composition. A more likely problem is that the Sun is gradually getting brighter. So far, the Earth’s temperature has remained fairly stable despite this, because the amount of carbon dioxide in the atmosphere has decreased over time, reducing the greenhouse effect and maintaining the same surface temperature. This compensation mechanism will eventually fail, leading to severe overheating and eventual extinction of life. But we do still have a few billion years!

Comments