What Are the Consequences of Increased CO2 Levels on Ocean pH?

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The Royal Society presents a PDF version of the Executive Summary of their report.In summary, the Royal Society has issued a report stating that the increase in atmospheric CO2 levels is causing higher concentrations in the oceans, leading to increased ocean acidity. This change in pH is expected to have a significant impact on marine organisms and ecosystems, particularly those that rely on calcium carbonate for shell formation. The effects of this ocean acidification can be seen in the decline of coral reefs and other organisms. The report also suggests that the ocean pH change will persist for thousands of years, and the rate of increase in CO2 levels is faster than natural occurrences in the past, making the acidification more severe. It is recommended to take action to curb the use of
  • #1
Skyhunter
Higher concentrations of CO2 in the atmosphere means higher concentrations in the oceans. This means the oceans become more acidic. It is predicted that the PH will change from 8.1 currently, to 7.7 in 100 years.

The Royal Society has just issued a summary report on the effects of CO2 on the pH chemistry of seawater and aquatic organisms and ecosystems. In addition to its pivotal role in the atmosphere in the regulation of global climate, CO2 and its sister chemical species, HCO3- and CO32- comprise the carbonate buffer system which regulates the pH of seawater. The new report can be found here. Acidifying the ocean is particularly detrimental to organisms that secrete shell material made of CaCO3, such as coral reefs and a type of phytoplankton called coccolithophorids [Kleypas et al., 1999]. The ocean pH change will persist for thousands of years. Because the fossil fuel CO2 rise is faster than natural CO2 increases in the past, the ocean will be acidified to a much greater extent than has occurred naturally in at least the past 800,000 years [Caldeira and Wicket, 2003].

http://www.realclimate.org/index.php?p=169

This can have catastrophic effects on ocean flora and fauna. Whether or not one believes in AGW, the pollution and other side effects of burning fossil fuels should be reason enough to take action to curb the use of fossil fuels.

[Edit] Here is a link to the Royal Society press release. There is a link to the PDF and related articles as well.

http://www.royalsoc.ac.uk/document.asp?id=3249 [Broken]
 
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  • #2
Sounds bad, but I don't know anything about it. I have no idea what the scale is for the increase in CO2 ppm.
 
  • #3
Somewhere else I had posted:

The oceanic alarm comes from:


Orr, James C. et al., 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature Vol. 437, No 7059, pp. 681-686, September 29, 2005

Abstract
Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pH and carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms—such as corals and some plankton—will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean−carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual' scenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously."

and

The Royal Society, 2005. Ocean acidification due to increasing atmospheric carbon dioxide. Policy document 12/05, June 2005, online http://www.royalsoc.ac.uk/displaypagedoc.asp?id=13314 [Broken]

..which elicited this comment:

Junkscience.com (Steven Milloy) comments July 1, 2005:

“Hmm... The Royal Society sure has a bee in its collective bonnet over anthropogenic greenhouse emissions lately.

Check out the Ordovician Mass Extinction. Note that fauna of the period included large diversity of corals, bryozoans, bivalves and gastropods (we know most about these because shells and skeletal remains fossilise best). In fact, reef builders took something of a hiding in Earth's second-most devastating mass extinction event.

Why is this significant? Well, all these shelled and reef building critters were apparently doing fine when atmospheric carbon dioxide levels were an order of magnitude greater than current and anticipated levels. If these creatures, many of whose descendants are current denizens of the seas, managed to fashion calcium carbonate shells and skeletons then it would appear that atmospheric CO2 levels are not a major determinant of the success of these marine creatures. Why would apparently insignificant levels be a problem now?”

Something like that seems so be confirmed by
Pelejero, Carles, Eva Calvo, Malcolm T. McCulloch, John F. Marshall, Michael K. Gagan, Janice M. Lough, and Bradley N. Opdyke, 2005. Preindustrial to Modern Interdecadal Variability in Coral Reef pH. Science Vol. 309, No 5744, pp. 2204-2207, September 30, 2005

The oceans are becoming more acidic due to absorption of anthropogenic carbon dioxide from the atmosphere. The impact of ocean acidification on marine ecosystems is unclear, but it will likely depend on species adaptability and the rate of change of seawater pH relative to its natural variability. To constrain the natural variability in reef-water pH, we measured boron isotopic compositions in a 300-year-old massive Porites coral from the southwestern Pacific. Large variations in pH are found over 50-year cycles that covary with the Interdecadal Pacific Oscillation of ocean-atmosphere anomalies, suggesting that natural pH cycles can modulate the impact of ocean acidification on coral reef ecosystems.

The authors developed a reconstruction of seawater pH spanning the period 1708-1988, based on the boron isotopic composition (d11B) of a long-lived massive coral (Porites) from Flinders Reef in the western Coral Sea of the southwestern Pacific.

"there is no notable trend toward lower d11B values over the 300-year period investigated.

…."the dominant feature of the coral d11B record is a clear interdecadal oscillation of pH, with d11B values ranging between 23 and 25 per mil (7.9 and 8.2 pH units)," which "is synchronous with the Interdecadal Pacific Oscillation." Furthermore, they calculated changes in aragonite saturation state from the Flinders pH record that varied between ~3 and 4.5, which values encompass "the lower and upper limits of aragonite saturation state within which corals can survive." Despite this fact, they report that "skeletal extension and calcification rates for the Flinders Reef coral fall within the normal range for Porites and are not correlated with aragonite saturation state or pH

Pelejero et al.'s 300-year record of these parameters began "well before the start of the Industrial Revolution" provides no evidence of any anthropogenic decline. They found that huge cyclical changes in the parameters had essentially no detectable effect on either coral calcification or skeletal extension rates and consequently the sensitivity of coral calcification rate to changes in pH and aragonite saturation state is much less than the alarmists claim to be.
 
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  • #4
Mk said:
Sounds bad, but I don't know anything about it. I have no idea what the scale is for the increase in CO2 ppm.
What is unprecedented here is not the higher concentration of CO2 in the atmosphere. It is the rate of increase that is alarming. The oceans and the life in them do not have the generations normally associated with such changes to adapt and adjust.

This document details the ocean acidification process in great detail.

http://www.royalsoc.ac.uk/displaypagedoc.asp?id=13539 [Broken]

It is not necessarily just the pH, which varies in the oceans from 8.2 - 7.8 depending on regional and seasonal variations. There is also the concentrations of CO3. Explained more fully here.
Therefore, CO3- concentration may be more relevant for calcifying marine organisms than pH.
 
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  • #5
Increase in surface CO2 concentration is also consistent with the consequences of overfishing --- the microbiota is not compacted into fecal pellets that settle rapidly into deep water, and remains in a "short-circuited" surface carbon cycle. Normal ocean turnover over a century brings 300 m or so of deep, pH ~ 7.5, water to the surface.
 

1. How are oceans becoming more acidic?

Oceans are becoming more acidic due to the absorption of carbon dioxide from the atmosphere. As more carbon dioxide is emitted from human activities such as burning fossil fuels, a significant amount of it is absorbed by the ocean, causing a decrease in pH levels.

2. What is causing the increase of carbon dioxide in the ocean?

The increase of carbon dioxide in the ocean is primarily caused by human activities, particularly the burning of fossil fuels. This releases large amounts of carbon dioxide into the atmosphere, which is then absorbed by the ocean.

3. What are the consequences of ocean acidification?

Ocean acidification can have a range of consequences, including the destruction of coral reefs, changes in the behavior of marine species, and a decline in the growth and survival of shell-forming organisms. It can also disrupt the balance of marine ecosystems and impact the seafood industry.

4. Can ocean acidification be reversed?

While it is not possible to completely reverse ocean acidification, reducing carbon emissions can help slow down the process. Additionally, implementing sustainable practices and reducing pollution can also help mitigate the effects of ocean acidification.

5. Is it too late to stop ocean acidification?

While the ocean has already become more acidic, it is not too late to take action to slow down the process. By reducing carbon emissions and implementing sustainable practices, we can help mitigate the effects of ocean acidification and protect marine ecosystems for future generations.

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