Ocean Acidificaition (Week 12) - Post 2

Ocean Acidification

          One of the most important aspects of our climate system is the ocean. It regulates 70 percent of Earth's surface and makes up 73 percent of the earth's water. The ocean absorbs more carbon each year, than any other earth system. The main reason the planet is still habitable for humans is because the ocean absorbs so much carbon dioxide. However, all of the carbon the ocean is absorbing is not natural, and it has negative effects on marine life and their ecosystems. This effect is referred to as ocean acidification. This is the term used to define the given chemical changes in the ocean as a result of carbon emissions. Since the beginning of the Industrial Revolution, when humans began releasing meaningful amounts of carbon dioxide into the air, the ocean has absorbed about a quarter of it each year. So as atmospheric levels of CO2 increase so do the levels in the ocean. It may seem like a good thing that the ocean removes so much of the CO2 from the atmosphere, but upon further inspection a serious downside is seen. The process of ocean acidification is one of chemistry. When dissolved CO2 mixes with ocean water chemical reactions take place that reduce seawater pH, carbonate ion concentration, and saturation of calcium carbonate minerals. All the years of CO2 emissions so far have caused the surface ocean waters to fall by 0.1 pH, this may not seem like a lot, but the pH system is on a logarithmic scale, so a drop by 0.1 means a drop by 30 percent. This has devastating effects on calcifying organisms in the ocean. The organisms build their skeletons and shells out of calcium carbonate in supersaturated parts of the ocean. Due to ocean acidification, there has been a severe drop in calcium carbonate saturated waters, affecting many marine organisms ability to produce and maintain their shells. Based on predictions of future human behavior scientists estimate that ocean acidity levels could raise by 150 percent by the end of this century, which would result in pH levels the ocean hasn't seen in more than 20 million years. This acidification of the oceans will have negative effects on several foundation species such as coral and Pterpods. Increasing CO2 levels and decreasing pH levels have been shown to significantly reduce reef-building coral's ability to produce skeletons. Ocean acidification has already, and will continue to impact coral reefs ability to recover from disturbance, and will cause them to erode faster. Pterpods are another example of a vital species that is affected by lower pH levels.  Pterpods rely on their calcium carbonate shells, which are easily eroded by ocean acidification. This poses a serious threat to marine life because pterpods are a staple in the diets of everything from tiny krill to whales. Ocean acidification uses increased CO2 to lower the pH of the oceans and negatively effect marine life and foundational species.
          The ocean absorbing high amount of carbon dioxide is very beneficial for the atmosphere and certain land ecosystems, but it has also had an equally negative effect on the ocean's ecosystems and marine life. It is uncertain whether or not the ocean has a tipping point with carbon intake, but it is already clear that we are heading towards it. It is important that carbon emissions are mitigated, in order to stop the harmful effects ocean acidification has on the ocean and marine life.