Ocean Acidification – global warming’s baby brother

Ocean Acidification.

It’s not often mentioned in the media. Talk to the general public, very few have heard of it.

So what is it? Probably the most underrated side effect of CO2 emissions. Some scientists would say it’s of greater consequence to our oceans than global warming.


When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals. These chemical reactions are termed “ocean acidification” or “OA” for short.

Through a chemical reaction with the higher atmospheric CO2 level, the oceans are becoming more acidic. Or if you wish to be pedantic, and god knows many denialists will be, it’s becoming less alkaline.

Either way, it’s not good for our ocean ecosystems. A simple search of scientific papers reveals many concerns (see below).

What does Joanne Nova say about it? Not much. Search her tags … and only one item comes up. Given the lack of media coverage on this item, I guess Nova can be forgiven for following suit.


There’s only a small portion of it devoted to ocean acidification, some results from a paper, Marine calcifiers exhibit mixed responses to CO2-induced ocean acidification …

They found that 10 out of 18 species suffered, 4 species grew stronger except at the highest CO2 levels, and crabs, lobsters, and shrimps just kept getting thicker shells as the CO2 increased, while blue mussels didn’t give a toss what the CO2 levels were.

Nova’s cheery news on Ocean Acidification is that at least 44% of species studied look to do ok.

Perhaps Nova will have more to say on the matter once the mainstream media realises the potential threat this poses to marine life.

List of Papers

Here’s just a few examples of the science conducted on ocean acidification (by no means a comprehensive list) gathered as a quick response to the claim that the term “ocean acidification” was misused or and that the problem was exaggerated by just a few scientists. A search of google scholar suggests this term is well used by the scientific community and that there are numerous papers from many scientists who share grave concern for the well-being of our oceans.


When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals. These chemical reactions are termed “ocean acidification” or “OA” for short.


Ocean acidification due to increasing atmospheric carbon dioxide. The oceans are absorbing carbon dioxide (CO2) from the atmosphere and this is causing chemical changes by making them more acidic (that is, decreasing the pH of the oceans).


Rising atmospheric carbon dioxide (CO2), primarily from human fossil fuel combustion, reduces ocean pH and causes wholesale shifts in seawater carbonate chemistry. The process of ocean acidification is well documented in field data, and the rate will accelerate over this century unless future CO2 emissions are curbed dramatically. Acidification alters seawater chemical speciation and biogeochemical cycles of many elements and compounds.


Ocean acidification is the lowering of pH in the oceans as a result of increasing uptake of atmospheric carbon dioxide. Carbon dioxide is entering the oceans at a greater rate than ever before, reducing the ocean’s natural buffering capacity and lowering pH. Previous work on the biological consequences of ocean acidification has suggested that calcification and metabolic processes are compromised in acidified seawater.


Ocean acidification is rapidly changing the carbonate system of the world oceans. Past mass extinction events have been linked to ocean acidification, and the current rate of change in seawater chemistry is unprecedented.


The surface ocean is everywhere saturated with respect to calcium carbonate (CaCO3). Yet increasing atmospheric CO2 reduces ocean pH and carbonate ion concentrations [CO32-] and thus the level of saturation.


Because the ocean absorbs carbon dioxide from the atmosphere, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states.


Southern Ocean acidification via anthropogenic CO2 uptake is expected to be detrimental to multiple calcifying plankton species by lowering the concentration of carbonate ion (CO32-) to levels where calcium carbonate (both aragonite and calcite) shells begin to dissolve.


Anthropogenic elevation of atmospheric carbon dioxide (pCO2) is making the oceans more acidic, thereby reducing their degree of saturation with respect to calcium carbonate (CaCO3).


Acidification had a profound impact on the development and growth of crustose coralline algae (CCA) populations. During the experiment, CCA developed 25% cover in the control mesocosms and only 4% in the acidified mesocosms, representing an 86% relative reduction.


We tested the effects that ocean acidification from elevated levels of atmospheric carbon dioxide (CO2) could have on the ability of larvae to detect olfactory cues from adult habitats. Larval clownfish reared in control seawater (pH 8.15) discriminated between a range of cues that could help them locate reef habitat and suitable settlement sites. This discriminatory ability was disrupted when larvae were reared in conditions simulating CO2-induced ocean acidification.


Atmospheric carbon dioxide (CO2) is increasing at an accelerating rate, primarily due to fossil fuel combustion and land use change. A substantial fraction of anthropogenic CO2 emissions is absorbed by the oceans, resulting in a reduction of seawater pH.


On a global scale, the alterations in surface water chemistry from anthropogenic nitrogen and sulfur deposition are a few percent of the acidification and DIC increases due to the oceanic uptake of anthropogenic CO2. However, the impacts are more substantial in coastal waters, where the ecosystem responses to ocean acidification could have the most severe implications for mankind.


The acidification caused by the dissolution of anthropogenic carbon dioxide (CO2) in the ocean changes the chemistry and hence the bioavailability of iron (Fe), a limiting nutrient in large oceanic regions.


While many problems such as warmer temperatures and rising sea levels are attributed to increasing carbon dioxide (CO2), there is one crucial problem that is often overlooked: Ocean acidification. As pH levels in the ocean fluctuate, there are devastating effects on sensitive marine ecosystems and individual species. Increased acidic conditions can pose threats to habitats, such as coral reefs and sea grasses. These living habitats rely on calcium carbonate to form strong external structures, yet higher pH levels inhibit the organisms’ ability to successfully absorb the compounds needed for this process.


The world’s oceans are slowly becoming more acidic. In the last 150 yr, the pH of the oceans has dropped by ~0.1 units, which is equivalent to a 25% increase in acidity. Modelling predicts the pH of the oceans to fall by 0.2 to 0.4 units by the year 2100. These changes will have significant effects on marine organisms, especially those with calcareous skeletons such as echinoderms.


We use a coupled climate/carbon-cycle model to examine the consequences of stabilizing atmospheric CO2 at different levels for ocean chemistry. Our simulations show the potential for major damage to at least some ocean ecosystems at atmospheric CO2 stabilization levels as low as 450 ppm.


Ocean acidification (OA), a consequence of anthropogenic carbon dioxide emissions, poses a serious threat to marine organisms in tropical, open-ocean, coastal, deep-sea, and high-latitude sea ecosystems. The diversity of taxonomic groups that precipitate calcium carbonate from seawater are at particularly high risk.


Ocean acidification (OA) and the biological consequences of altered seawater chemistry have emerged as a significant environmental threat to healthy marine ecosystems. Because a more acidic ocean interferes with fixation of calcium carbonate to form shells or calcified skeletons, future ocean chemistry may significantly alter the physiology of calcifying marine organisms.


However, ocean acidification affects not only the organisms, but also the reefs they build. The decline in calcium carbonate production, coupled with an increase in calcium carbonate dissolution, will also diminish reef building and the benefits that reefs provide, such as high structural complexity that supports biodiversity on reefs, and breakwater effects that protect shorelines and create quiet habitats for other ecosystems, such as mangroves and seagrass beds.


The ocean captures a large part of the anthropogenic carbon dioxide emitted to the atmosphere. As a result of the increase in CO2 partial pressure the ocean pH is lowered as compared to pre-industrial times and a further decline is expected. Ocean acidification has been proposed to pose a major threat for marine organisms, particularly shell-forming and calcifying organisms.


Ocean acidification : present conditions and future changes in a high-CO2 world – The uptake of anthropogenic CO2 by the global ocean induces fundamental changes in seawater chemistry that could have dramatic impacts on biological ecosystems in the upper ocean.


3 Responses to “Ocean Acidification – global warming’s baby brother”

  1. Bob Carter – same old stuff « itsnotnova Says:

    […] It will cause great damage, not only from the warming, but more directly in Ocean Acidification. […]

  2. Carbon Tax – Nova misleads – Perhaps you won’t notice. « itsnotnova Says:

    […] As previously discussed, Nova wishes to pretend that Ocean Acidification is not caused by the pollution of CO2 – she wishes to deny the existence of hundreds of scientific papers on the subject and instead pretend it’s no threat at all. […]

  3. Carbon dioxide is already absorbing almost all it can – really? « itsnotnova Says:

    […] the lowest climate sensitivity figure possible. She cites another Exxon-sponsored Idso scientist (recall the Ocean Acidification “science” they performed) for a climate sensitivity […]

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