Human activities have been responsible for many of the major changes in the global climate. The major human activity responsible for these drastic changes is the burning of fossil fuels, which contributes to massive amounts of carbon dioxide in our atmosphere. As a result to the high levels of carbon dioxide in the air, the ocean acts like a carbon dioxide sink, meaning it absorbs a large amount of carbon dioxide. The reason why the ocean is able to absorb so much carbon dioxide is because carbon dioxide readily dissolves in water and there is a continual cycling of equilibration between the levels of carbon dioxide in the atmosphere and in the ocean. Increased levels of carbon dioxide in the ocean has many negative effects, but the two most significant impacts include increased acidity and decreased formation of aragonite.