Most people invariably associate carbon emissions with atmospheric pollution, and the resultant negative impact on human life and health. However, elevated levels of atmospheric carbon dioxide can also leach into oceans over time, throwing the pH balance of the seawater completely off-balance and making them increasingly acidic.
How it happens
Of all the carbon emissions generated by human activities, 45 percent still remains in the atmosphere-the remainder is absorbed by oceans, and a small percentage is taken up by terrestrial plants. The absorbed carbon is largely in the form of inorganic carbon compounds such as carbon dioxide and carbonates, which react with water to form compounds such as dissolved free carbon dioxide, carbonic acid, bicarbonate and carbonate.
A result of this dissolution of carbon dioxide in seawater is an increase in the oceans' hydrogen ion concentration, thus decreasing the ocean pH. Since the Industrial Revolution of the 18th Century, the hydrogen ion content of the oceans has increased by approximately 29 percent. Experts estimate that by the year 2100, the acid concentration of the world's oceans will increase dramatically-even tripling from the existing levels if no substantial control measures are undertaken.
The rapid pace of acidification is triggering alarm bells for ecologists and marine life experts, who predict that if this acidification were to continue unabated, it will soon reach levels that are higher than anything the planet has witnessed in the past 65 million years.
Why is it dangerous?
The biggest threat from changes in the chemistry of ocean water is to marine organisms and their habitats. Increasing acidity is especially deleterious to the process of calcification, which involves the creation of calcium carbonate shells and plates. Calcification is a vital component of the lifecycles of a wide range of marine organisms, and a decrease in oceanic pH will prove threatening to their sustenance. Besides this, organisms may also suffer a variety of other harmful effects to their reproductive systems and general physiological health due to increased exposure to carbon dioxide. Recent research also suggests that acidification may interfere with the acoustic properties of seawater, allowing sound to propagate further. The resultant increase in ocean noise will adversely affect marine animals that use sound for navigational purposes.
While the planet's oceans have long served as a safety net of sorts in regulating the carbon content of the atmosphere, their carbon absorption abilities come at a steep cost-severe changes to ocean chemistry and a barrage of damaging implications for aquatic life. If this trend of arbitrarily dumping carbon into the atmosphere continues for much longer, scientists fear a relapse of the greenhouse event that struck the planet 55 million years ago, rendering many deep-water species extinct because of dramatic chemical changes to their underwater environment. Even as research is still underway to gauge the complete impact of acidification on the planet's oceans, the fact still remains that without timely measures, the damage may just go too far to be undone.
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