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What is Ocean Acidification?


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Question: What is Ocean Acidification?
The oceans have reduced the effects of global warming for thousands of years by absorbing carbon dioxide. Now the basic chemistry of the oceans is changing because of our activities, with devastating consequences for marine life.

It's no secret that global warming is a major issue. A main cause of global warming is our release of carbon dioxide, primarily through the burning of fossil fuels and the burning of vegetation. Over time, the oceans have helped this problem by absorbing excess carbon dioxide. According to NOAA, the oceans have absorbed nearly half of the fossil fuel emissions we've generated over the past 200 years.

As the carbon dioxide is absorbed, it reacts with the ocean water to form carbonic acid. This process is called ocean acidification. Over time, this acid causes the pH of the oceans to decrease, making ocean water more acidic. This can have drastic consequences on corals and other marine life, with cascading impacts on the fishing and tourism industries.

More About pH and Ocean Acidification

The term pH is a measure of acidity. If you've ever had an aquarium, you know that pH is important, and pH needs to be adjusted to optimal levels for your fish to thrive. The oceans has an optimal pH, too. As the ocean becomes more acidic, it becomes more difficult for corals and organisms to build skeletons and shells using calcium carbonate.

In addition, the process of acidosis, or buildup of carbonic acid in body fluids, may affect fish and other marine life by compromising their ability to reproduce, breathe and fight diseases.

How Bad is the Ocean Acidification Problem?

On a pH scale, 7 is neutral, with 0 the most acidic and 14 the most basic. The historical pH of sea water is about 8.16, leaning on the basic side of the scale. While it doesn't seem like this is a problem, the pH of our oceans has fallen to 8.05 since the beginning of the Industrial Revolution, a change greater in magnitude than any time in the 650,000 years before the Industrial Revolution. The pH scale is also logarithmic, so that slight change in pH results in a 30 percent increase in acidity.

Another problem is that once the oceans get their "fill" of carbon dioxide, scientists think the oceans could become a carbon dioxide source, rather than a sink. This means the ocean will contribute to the global warming problem by adding more carbon dioxide to the atmosphere.

What Can We Do About Ocean Acidification?

Lowering our emissions will help the ocean acidification problem, even if that just slows the impacts long enough to give species time to adapt. Read the Top 10 Things You Can Do to Reduce Global Warming for ideas on how you can help.

Scientists have acted swiftly on this issue. The response has included the Monaco Declaration, in which 155 scientists from 26 countries declared in January 2009 that:

  • Ocean acidification is accelerating and severe damages are imminent;
  • Ocean acidification will have broad socioeconomic impacts, affecting marine food webs, causing substantial changes in commercial fish stocks and threatening food security for millions of people;
  • Ocean acidification is rapid, but recovery is slow;
  • Ocean acidification can be controlled only by limiting future atmospheric carbon dioxide levels.

The scientists called for intense efforts to research the problem, evaluate its impacts and cut emissions drastically to help curb the problem.


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