Carbon Dioxide and Carbonate Chemistry of the Oceans

• Main Author: Cai, Wei‐Jun
• Format: Other/Unknown Material
• Language: English
• Published: Wiley 2019
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.1002/9781119300762.wsts0033; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F9781119300762.wsts0033; https://onlinelibrary.wiley.com/doi/pdf/10.1002/9781119300762.wsts0033; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/9781119300762.wsts0033

Abstract This article describes the acid–base properties of dissolved inorganic carbon (DIC) and the features of its distribution and cycling in the ocean. The DIC pool increases and becomes more enriched in molecular carbon dioxide (CO 2 ) and lower in pH from surface to subsurface and from younger to older waters. Waters “age” and accumulate CO 2 as the deep ocean current moves around the global ocean, as organic matter settling from the productive sea surface is decomposed into CO 2 by microbes, and as calcium carbonate minerals are dissolved in the deep sea. In at least the past 500 000 years, CO 2 in the atmosphere regularly varied tightly between an upper bound of 280 and a lower bound of 180 ppm over several glacial cycles, indicating that the Earth's climate system and ocean carbon cycle were stable. Such stability has been disturbed at an unprecedented rate since the Industrial Revolution as human use of fossil fuel, and deforestation have released large amounts of CO 2 into the atmosphere and have pushed the atmospheric CO 2 level to over 400 ppm today. Part of the released anthropogenic CO 2 is taken up by the ocean, which has slowed down the greenhouse gas increase in the atmosphere but has acidified the seawater and altered ocean chemistry. This process, called ocean acidification, will continue and likely endanger marine organisms and ocean biological systems.