The world’s oceans have largely been left out of the mainstream discussion of global climate change. Yet, as one of the largest natural reservoirs of carbon, the surface ocean plays a critical role in the global carbon cycle. Over recent years, human activities such as the burning of fossil fuels have increased the amount of carbon dioxide gas emitted to the atmosphere and the amount that dissolves into the ocean. Over the last decade, scientists have discovered that this excess CO2 is actually changing the chemistry of the sea and proving harmful for many forms of marine life. This process is known as ocean acidification. A more acidic ocean could wipe out species; disrupt the food web and impact fishing, tourism and any other human attempt that relies on the sea. The change is happening fast - and it will take fast action to slow or stop it. According to an estimate by scientists, Over the last 250 years, oceans have absorbed 530 billion tons of CO2, triggering a 30 percent increase in ocean acidity. The Polar Regions will be the first to experience changes. Projections show that the Southern Ocean around Antarctica will actually become corrosive by 2050.
Carbon dioxide is a critical part of Earth’s atmosphere; it traps heat and prevents the Earth from being covered in ice. Normally, the Earth’s carbon cycle maintains a natural balance of carbon in the atmosphere, land, and ocean through the “breathing of the planet”. Not all of the excess carbon dioxide stays in the atmosphere. Scientists estimate that one-third of all the carbon dioxide produced by human activities has been absorbed by the ocean. The absorption of carbon dioxide is making seawater more acidic.
Atmospheric carbon dioxide is absorbed by the ocean, where it reacts with seawater to form carbonic acid (H2CO3). Almost immediately, carbonic acid dissociates to form bicarbonate ions (HCO3) and hydrogen ions (H+). As the concentration of hydrogen ions increases, the...
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