Ocean acidification is becoming an increasingly prevalent problem- the current rate of acidification is 0.1pH per century. This affects many aspects of Earth’s natural systems- marine ecosystems, global climate cycles, and even the geology and geography of the Earth.
While a serious problem, the mechanism behind it is relatively straightforward: Ocean acidification is a decrease in the oceans’ pH level. Quite literally, pH stands for “power of Hydrogen” and so a lower pH means a higher concentration of Hydrogen ions (H+) are present in a substance. Further reading can be found here. The drop in pH level is caused by the diffusion, or movement, of atmospheric CO2 into the oceans. This is a natural process and happens without any human intervention.
As seen in the above diagram, atmospheric CO2 can be generated in a number of ways; naturally, via biological processes such as respiration:
As well as by volcanic eruptions, where CO2 is one of many gases released.
CO2 is also taken out of the atmosphere by natural processes- diffusion into the sea or by mountain building, for example, as well as photosynthesis in plants:
The problems arise when excess CO2 is generated over a larger period of time, such as the burning of fossil fuels. The increase in atmospheric CO2 disturbs the equilibrium, or balance, between the concentration of CO2 in the atmosphere and in the Ocean, and so CO2 moves into the ocean by dissolving and forming carbonic acid to restore this balance.
In part 2, we will have a look at some of the impacts of Ocean Acidification and how they may be predicted.
Carbon Cycle (no date) Available at: http://www.physicalgeography.net/fundamentals/images/carboncycle.jpg.
Helmenstine, A.M. (2017) What does pH stand for? What pH means. Available at: http://chemistry.about.com/od/ph/f/What-Does-Ph-Stand-For.htm.
marshall, michael (2012) Oceans acidifying at unprecedented speed. Available at: https://www.newscientist.com/article/dn21534-oceans-acidifying-at-unprecedented-speed/.
Photosynthesis Equation (no date) Available at: http://additionalbio.blogspot.co.uk/2014/09/photosynthesis.html.
Respiration Equation (no date) Available at: https://examhints.files.wordpress.com/2014/09/respiration-1.png.