Now, as the earth does not become rapidly overheated from CO2 (carbon dioxide) in the atmosphere, nor the Arctic sea ice disappearing, nor the Pacific atolls drowning, nor the Amazonian jungle drying up, all as previously touted by the IPCC and their gendarmes and adjuvants, a new slogan on the supposed danger of CO2 is increasingly being heard, namely “Ocean Acidification”.
The supposedly happening Ocean Acidification, frequently termed “the other effect of CO2”, is largely based on unrealistic biological experiments, actual measurements over an insufficient time to allow any definite trend delineation, and a lack of understanding of the chemistry involved.
Oceans and most freshwater bodies are alkaline
Water is acidic if the pH is below 7 and alkaline if it is above 7. The pH of the oceans and most freshwater is approximately 8 to 8.2. The pH fluctuates with the seasons, increasing in spring and summer, decreasing after that. As the level of CO2 in the air is nearly constant, one has to ask:
#Why does the ocean pH change with the seasons, and
#Why are the oceans alkaline to begin with?
The answer to the first question is the process of photosynthesis. Plants convert CO2 with the energy from sunlight and the use of other nutrients to produce more plant matter. This process is most pronounced when the sunlight intensity reaches a maximum in spring and summer. Also, after a long fall and winter, when photosynthetic activity is reduced, an increased supply of the other nutrients is available.
The answer to the second question is really the same as the one to the first question. In a functioning ecosystem, such as the oceans, the overall effect over many annual cycles of photosynthetic activity is an increase in water pH. That is why the oceans are alkaline.
Photosynthesis counteracts the acidic effect of CO2
The photosynthesis process by plants on land (such as trees), reduces the CO2 to non-acidic plant matter. To understand this, one needs to know that the two oxygen atoms bound to the same carbon atom in carbon dioxide are the cause of the acidic effect of dissolved CO2. The reduction of CO2 (loss of oxygen) during the photosynthesis causes the resulting compounds (plant matter, chemically sort of [CH2OH]) to be essentially free from any acidic effect. If you have ever tasted a piece of raw wood (such as a popsicle stick), you will know that it is not acidic. Yet, 100% of the carbon in that popsicle came from atmospheric CO2!
The photosynthesis process by algae in the water also reduces CO2 to non-acidic plant matter. In addition, it incorporates nitrogen to create alkaline amines which increase the pH. The “fishy” smell of fish and other marine and freshwater organisms is caused by such amines.
Oxygen in the air
Our air is composed of approximately 20% oxygen and 0.04% CO2. This free molecular oxygen is vital for man and animals on land and in water. We consume it by breathing in and then our bodies burn (oxidize) stored carbon materials and expel the so-produced CO2 (at a concentration of approximately 5%, or 50,000 parts per million). Yet, the only known source of free molecular (not bound to other elements) oxygen is CO2. All the oxygen in the air was created through the photosynthetic process by plants converting the (natural) CO2 over many millions of years.
In order to prove the supposedly negative effects of CO2 on organisms in water, some researchers are testing the response of various organisms to an increased level of CO2 in the water. Such experiments are typically performed in laboratories over a short period of time, ranging from hours to days. Obviously, the sudden influx of CO2 to the water does cause (relative) acidification, and the organisms are not happy about that. However, these experiments do not reflect what is happening in nature as they omit the counteracting effect of photosynthesis in nature. Such experiments are entirely unrealistic as to what happens in the environment.
Natural sources of CO2
While mankind has undoubtedly added CO2 to the air, most of the CO2 in the air is from natural sources. Before man’s arrival, all CO2 was from natural sources, primarily from volcanoes. The CO2 is emitted by thousands of volcanic vents both on land and under water along some 60,000 km of tectonic rifts which criss-cross the earth. For example, the Kilauea volcano on Hawaii alone emits daily some 9,000,000 kg CO2 into the surrounding air, at a concentration of 500,000 parts per million or 50% of the emitted gas.
To sum it up
Oceans and most freshwater bodies are alkaline with a pH of approximately 8.
Air is composed of approximately 20% oxygen and 0.04% CO2.
Most CO2 in the air is from natural sources, primarily from volcanoes.
All oxygen in the air has been produced by plants on land and in water from CO2.
Plants use the photosynthesis process to convert CO2 to plant matter and oxygen.
Without CO2 in the air, no plants could make oxygen.
The products of photosynthesis are substances which increase the pH.
Ocean acidification may happen, but not because of increased CO2 in the atmosphere.
CO2 and photosynthesis are vital to most life on earth.