It has already, especially affecting the abilty of shellfish to grow shells.
http://www.sciencedaily.com/releases/201...
This is not new, shellfish have always adapted this way to changes in ocean pH. The concern with anthropocentric changes is that the pH may be changing too fast for shellfish to evolve which thereby puts major food sources at risk.
http://www.sciencedaily.com/releases/201...
http://blogs.nature.com/climatefeedback/...
Funny how deniers mention the vastness of the ocean and precipitation while ignoring that the CO2 dissolved in the mixed layer has to track with the partial pressure of CO2 in the atmosphere, and the mixed layer is only about 1/40 the volume of the ocean.
While we know that oyster propagation, for example, has already been affected enough by acidification to have an economic impact, we really won't know how fast other effects will occur until they happen, and we don't know if there will be permanent adverse effects. Most knowledgeable biologists would prefer not to do the experiment and are watching with fingers crossed.
Here is a diagram that lays out the averages from the National Oceanic and Atmospheric Administration. (NOAA).
http://www.pmel.noaa.gov/co2/story/Carbo...
Note that a Petagram (Pg) is a billion metric tons. So the answer is ~ 38,000 Gigatons. About 135 Gigatons have been added due to anthropogenic emissions. Values will change as temperature of the oceans and atmosphere change.
Here is a page from NOAA that talks about ocean acidification.
http://coralreef.noaa.gov/education/oa/p...
The first corals and shellfish appeared in the Cambrian period (a period known for the explosion of life) this period had some of the highest levels of CO2 ever.
The Oceans are at a PH of 8.1/ 8.2 this is alkaline, PH7 is neutral below this is acidic, to reduce oceans (70% of our earth 3km deep) to below PH7 is impossible as there is insufficient carbon on earth in any form to do it.
P.s. shellfish also form in fresh water rivers and lakes which are not alkaline.
shellfish combine CO2 with calcium to make calcium carbonate (their shells) without CO2 they would have no shells.
The ocean doesn't store carbon. If you have a glass of water and put salt in it. Eventually that glass will be saturated. What happens when you put additional salt in it? It precipitates out. The ocean is far more complex than a glass and some parts are precipitating while other parts are still able to absorb more. Still, as with the salt in the simple example above, if you add more carbon, it should precipitate out in greater quantities as it has done for billions of years.
Just because humans are emitting the carbon, it doesn't mean that it is now stuck and stored in the ocean.
Bacheus says it already has and he links to a magazine with the headline:
"Scientists Predict Impact of Ocean Acidification On Shellfish"
I know alarmists think that prediction equal reality particularly since reality isn't on their side and prediction of catastrophe is their only evidence of catastrophe.
It doesn't work that way and tbh I can't be bothered to explain weak acids and association constants and their relation to temperature and pressure etc etc. To cut to the chase you've brought into a lie, and increased ocean acidity (or to be more accurate a less alkaline ocean) is probably the biggest agw lie ever told.
maybe 100,000 giga tons
At what point does the resulting acidification change marine ecosystems forever.
