Carbon Dioxide and pH


Global systems and cycles
The carbon cycle is vital to life on Earth. All living things are carbon based, even humans. Carbon is released naturally into the atmosphere through respiration and volcanic eruptions. Plants remove the carbon from the atmosphere through photosynthesis and use it to build cells and grow. Animals eat plants and thus gain the carbon they need to grow from them. When organisms die, they generally decompose and carbon is returned to the atmosphere. Sometimes they are buried in such a way that they are lithified or turned into oil and gas (fossil fuels).
CO2_temp, accessed 23/4/2020
The carbon cycle has been in a natural balance for millions of years. However, since the Industrial Revolution the amount of carbon dioxide in the atmosphere has increased significantly (ACS). The oceans play a major role in absorbing carbon dioxide from the atmosphere and are the largest carbon sink. They absorb over 20 million tonnes of carbon a day. Initially scientists were relieved about this, however in the past two decades they have come to realise that this can have devastating impacts on marine life.
Mussels, accessed 23/4/2020
You can see from this investigation as more carbon dioxide is absorbed into water the acidity of the water increases. Just a small change in the pH of ocean water can cause problems for some marine life. Many bivalves, such as oysters and muscles, are struggling to make hard outer shells. Other species are finding that their shells are starting to dissolve, like how carbonated drinks can dissolve tooth enamel. Some fish have shown they do not develop as well mentally or physically with increased acid in their environment. All these creatures make up parts of a bigger food chain. If they do not grow big enough, or at all, then animals higher up the food chain will begin to struggle, including humans.
Dead tooth, accessed 23/4/20202
Without making changes to our lifestyles the problem will only continue to get worse. Why not try using a carbon footprint calculator to see what steps you can take to reduce your emissions.
For a scientific explanation of the chemical reactions involved with acidification of the oceans, read this article and watch the animated videos.
For more hands on activities you can try at home relating to carbon dioxide in the oceans try these WASP activities.