Introduction to Ocean Acidification

Ocean acidification is one of the top environmental issues today. Ocean acidification as a term means that the oceans are becoming more acidic. This trend is worrying to environmental scientists, as they have studied this to know that almost all ecosystems (particularly those that exist closer to the ocean surface) will be affected in one way or the other.

What is ocean acidification?

It is the changes in the chemical composition of ocean waters. It also includes changes in its temperature resulting from excess carbon dioxide (CO2) in the atmosphere. The changes cause the lowering of the pH of the water.

To understand this better, we need to first understand what pH is, together with Atmospheric Carbon Dioxide.

What is the pH of water?

The pH of water is the measure of how acidic or basic water is. The scale is from 0 to 14, and 7 is the neutral point (pure water). If the pH is closer to 0, that water is more acidic. If it is closer to 14, the more basic it is.

“During the last 20 years, it has been established that the pH of the world’s oceans is decreasing as a result of anthropogenic carbon dioxide emissions to the atmosphere.” *1

Lower pH seas and oceans are known to cause major problems for marine organisms and ecosystems.

Carbon Dioxide (CO2)

The atmosphere is made up of air. Air is composed of gasses including Oxygen at 21%, Nitrogen at 78%, Argon at 0.9%, and Carbon Dioxide at 0.04%. These gasses occur naturally in the atmosphere. However, the concentrations of atmospheric carbon dioxide in the atmosphere have increased a lot since the industrial revolution. Humans are burning a lot more fossil fuels than ever before. Fossil fuels are the main source of CO2. It is known that the Amazon, together with other major forests covers are large absorbers of CO2 from the atmosphere, but, the Oceans, is the largest carbon sink on the planet.

Now we shall see a bit more about how acidification occurs. 


1. Third Symposium on the Ocean in a High-CO2 World, UNESCO, Ocean Acidification.,
2. Ocean Acidification Will Make Climate Change Worse, By Bryan Walsh, TIME.

Recommended Environmental Lessons

Key words: Ocean-acidification, pH, ocean-acidity, CO2, carbon-dioxide, biological-carbon-pump, calcification, calcifiers, shell-fish, coral-reefs, environmental-issue, biodiversity