Ocean Pollution

Good Essays
Chapter 1


Rising atmospheric carbon dioxide from fossil fuel combustion is increasing dissolved inorganic carbon (DIC) and reducing pH in the global surface ocean (Edmunds et al. 2016). Recent estimates suggest that one-quarter of carbon dioxide emissions originating from human fossil-fuel combustion is absorbed by the world’s oceans (Le Quéré, et al. 2015), causing a shift in the seawater carbonate chemistry. As a result, oceans have seen large increases in bicarbonate ions and decreases in concentrations of calcium carbonate ions and pH of the seawater; in a process known as ocean acidification. Since preindustrial times, atmospheric carbon dioxide absorbed by the oceans has lowered the pH of the seawater by 0.1 units, which equates to approximately a 30% increase in acidity. In addition, carbonate ion concentrations have decreased by 11%-15% in the tropics and southern oceans (Orr et al. 2005). According to the IPCC, under a “business as usual” approach to climate change, carbon dioxide absorbed by the oceans will cause a pH decrease of 0.77 units by 2030 (Caldeira and Wickett 2003). This increase in acidity will cause decreases in carbonate ion concentration and lead to a reduction in the saturation states of aragonite, calcite and high magnesium calcite, which may lead to a reduction in calcification in marine organisms (Feely et al. 2004; Gattuso et al. 1999; Langdon and Atkinson 2005; Anthony et al. 2008). With a doubling of atmospheric pCO2 from
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