• Question: will the world ever run out of oxygen?

    Asked by King holly to Connor, Jillian, Lidunka, Sarah, Steven on 16 Jun 2015.
    • Photo: Steven Thomson

      Steven Thomson answered on 16 Jun 2015:

      Thankfully, no! The total amount of oxygen in the world doesn’t change – our bodies take the oxygen in the air and make it into carbon dioxide (a molecule with one carbon atom and two oxygen atoms), but then we breathe it back out and plants and other animals break down this carbon dioxide back into carbon and oxygen, which goes back into the atmosphere. So there’s no need to worry about us ever running out of oxygen!

    • Photo: Lidunka Vocadlo

      Lidunka Vocadlo answered on 16 Jun 2015:

      @King holly Wow – that’s a great question. On the short timescale, Steven is right. There’s a nice little balance going on in the atmosphere that suits us perfectly. But the Earth didn’t always have oxygen – in fact it had hardly any for first couple of billion years (almost half it’s life), then a little increase, then a big increase about 600 million years ago. Scientists are still arguing the causes for these dramatic climatic changes and whether it’s possible we could go back into a low/no oxygen environment. But I think you’re ok for the time being!

Comments