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The USA's National Oceanographic and Atmospheric Administration estimates that the oceans absorb almost 1/3 of the CO2 emitted- 22 million tons/day into the oceans-
Again, a situation that we don't know the consequences of, but unlike 'AGW' we do know that it's real and human activities are the cause.

http://www.pmel.noaa.gov/co2/s.../Ocean+Acidification
Ocean Acidification: The Other Carbon Dioxide Problem

Fundamental changes in seawater chemistry are occurring throughout the world's oceans. Since the beginning of the industrial revolution, the release of carbon dioxide (CO2) from humankind's industrial and agricultural activities has increased the amount of CO2 in the atmosphere. The ocean absorbs almost a third of the CO2 we release into the atmosphere every year, so as atmospheric CO2 levels increase, so do the levels in the ocean. Initially, many scientists focused on the benefits of the ocean removing this greenhouse gas from the atmosphere. However, decades of ocean observations now show that there is also a downside — the CO2 absorbed by the ocean is changing the chemistry of the seawater, a process called OCEAN ACIDIFICATION.

This message has been edited. Last edited by: SUB,
 
Location: Vancouver Island, Canada | Registered: September 30, 2001Reply With QuoteReport This Post
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-Found a site that is skeptical:
http://www.seafriends.org.nz/issues/global/acid.htm

Nothing in the sea works as expected:
its physics, chemistry, biochemistry, physiology, biology and ecology do not work as thought;
truth is often opposite to intuition.
The sea is weirder than we can possibly imagine.
To learn about the sea, forget what you were taught at school, open your mind and begin from scratch.

It is an important message that I want you to take home and keep in the back of your mind whenever you read about marine science or planet science. It is a message for scientists too.

Dead planet thinking: most oceanographers, physicists, chemists treat the planet as a dead planet, where every force, every process can be described and captured in an equation, and then simulated by a computer. But life frustrates every attempt, as it corrupts equations, while also adapting to changing circumstances. Of all these, the sea is the worst with its unimaginable scale, complexity and influence. We may never be able to unravel the secrets of the sea.
 
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Originally posted by RickDaTech:
SUB has latched on to something that might possibly link elevated CO2 levels to mass extinctions. So fill a big tank with seawater populate it with aquatic life and see what it really happens. Use the scientific method if you are going to claim a scientific foundation. I've read more than a handful of reports from the USGS where they used the scientific method to determine the effect of elevated CO2 levels on plant and animal life.

Looks like they're applying scientific methods to their work-

Ocean acidification: Some Winners, Many Losers
Posted on 10 June 2011 by Rob Painting

Numerous lab experiments have shown that ocean acidification is harmful to marine life. Creatures that build chalk-like shells (or skeletons) fare poorly under conditions which mimic the low ocean pH levels expected later this century. This isn't a universal response however; some starfish, brittle stars and sea urchins, seem relatively unaffected by ocean acidification, so it's likely there will be winners and losers as the world's oceans become less alkaline.
Nature's own laboratory

Despite their usefulness, lab experiments are no substitute for the natural environment, and experiments tend to be of short duration too, so the long-term effects of elevated CO2 on marine communities is largely unknown. Luckily there are a couple of locations in the world which mimic ocean acidification. These locations are not perfect analogues for the future, seawater acidity is not held permanently low because of seasonal wind and current variation, for example, but they do give some insight into how marine life might adapt (or not) to ocean acidification over the long haul.

Fabricius 2011 examines the coral reefs in one such area, Milne Bay Province in Papua New Guinea, where cool CO2 bubbles up through natural seeps on the seafloor, thereby lowering seawater pH. The authors examined underwater sites which are equivalent to 3 ocean pH scenarios: a control site, where seawater is at ambient (normal) pH (around 8.1), a low pH site (7.8-8.0), and a very low pH site (below 7.7).

Figure 1 -Seascapes at a, control site (‘low pCO2’: pH~8.1), b, moderate seeps (‘high pCO2’: pH 7.8–8.0), and c, the most intense vents (pH<7.7), showing progressive loss of diversity and structural complexity with increasing pCO2. d, Map of the main seep site along the western shore of Upa-Upasina. Colour contours indicate seawater pH, and the letters indicate the approximate locations of seascapes as shown in a–c.

What the authors found, is probably no surprise: as the level of seawater pH dropped from it's normal value of 8.1, the health of the reef began to deteriorate. Various hard and soft corals, and other hard-shelled marine life, such as cructose coralline algae, disappeared from the seafloor. Only one type of coral was able to tolerate ph as low as 7.8, which is equivalent to 750 ppm of atmospheric CO2: a figure we're on track to reach before the end of the 21st century. Below a pH of 7.7 however, coral reef development stopped dead in it's tracks. The beneficiaries, it turns out, are slime (macroalgae) and seagrasses, with their populations flourishing as seawater becomes more acidic.

Another discovery made by the authors, is that coral reef growth (calcification) was 30% lower than is the norm for coral reefs at similar latitude (distance from the equator), and both the low and ambient pH sites exhibited the same condition. The Milne Bay area has experienced repeated mass coral bleaching events in the last 20 years, so this has probably played a role in the low growth rates. This is consistent with the latest research showing coral growth rates have diminished worldwide in recent decades.
 
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CO2 Currently Rising Faster Than The PETM Extinction Event
Posted on 17 June 2011 by Rob Painting

Lessons from a previous global warming event

The PETM took place at a point in Earth's development when the climate was very different than today. It's important to stress that none of the preceding discussion implies that direct and complete comparisons can be made between the Earth climate of today, and the Earth climate of 56 million years ago. Much has changed since then, such as the layout of the continents, and the development of major mountain chains such at the Himalayas and Andes, the growth of major ice sheets, major cooling of the deep ocean and the poles, slight warming of the Sun, and changing Earth-Sun orbital characteristics, all of which greatly alter global circulations and therefore climate.

But now that we humans have embarked on a global warming experiment, there are some useful lessons from the past:

The rapid pulse of PETM CO2 followed by rapid warming (figure 2e) indicates high climate sensitivity.

CO2 does indeed appear to have a long atmospheric lifetime.

Ocean acidification (of the deep sea at least) can occur even under conditions of CO2 release much slower than today.

Present acidification of the ocean is far greater than the PETM, and is probably unprecedented in the last 65 million years.

Whether the plants and animals upon which humans depend can survive the present rapidly changing environment remains to be seen.
 
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Lots of evidence that CO2 was involved-

Permian-Triassic Extinction:


One of the most dramatic and mysterious events in the history of life, the so-called "Great Dying" of animals and plants some 250 million years ago, continues to fascinate and baffle scientists. Of the five or so mass extinctions recorded in Earth's fossils, this one at the end of the Permian period and the start of the Triassic was the most catastrophic.

More than half of the families of living things died out, and as many as 90 to 96 percent of the planet's marine species were lost. At the same time, perhaps 70 percent of the land's reptile, amphibian, insect, and plants species went extinct.

The $64,000 question is what event, or chain of events, could have wreaked such environmental disaster? It's a bit like trying to solve a 250-million-year-old crime -- the trail is cold, and many clues have been destroyed. At this time the continents as we know them today were assembled into a single landmass called Pangaea, which did not start to break up until the middle of the Triassic period. This gargantuan supercontinent, scientists suspect, disrupted the circulation of seawater, making the oceans stagnant. The consequent depletion of oxygen in the water and high concentrations of dissolved carbon dioxide rendered the ocean bottom something like an enormous bog.

The anoxic (oxygen-lacking) waters could have spilled onto the continental shelves, the high carbon dioxide content, toxic to marine life, poisoning much of the life in the oceans. At the same time, massive outpourings of volcanic basalt rock in what is now Siberia added huge amounts of heat, carbon dioxide, and sulfur dioxide to Earth's surface and atmosphere. The carbon dioxide could have trapped heat in the atmosphere, and the resulting "greenhouse effect" generated a long warming trend.

The climate change triggered by the warming could have shifted weather patterns dramatically, so that regions normally wet and rainy became dry and vice versa. Geologic evidence supporting this hypothesis has been found in recent investigations in the Caledon River in South Africa.

Did all these factors -- sea-level change, climate change, ocean stagnation, carbon dioxide buildup -- combine to cause the Great Dying? We don't have all the answers. And, in fact, in 2001 a group of scientists uncovered evidence suggesting that an asteroid may have hit Earth at the end of the Permian era, further complicating the picture. The evidence is still circumstantial, however, and what role, if any, an impact may have played is unclear.

Scientists continue to examine the evidence for clues to the cause of the Permian-Triassic extinction. But this dramatic event happened so long ago that we may never know for certain what wiped out so much of life on Earth in the Great Dying.

\
Permian–Triassic extinction event
From Wikipedia, the free encyclopedia

Edited to focus on marine aspects-

The Permian–Triassic (P–Tr) extinction event, informally known as the Great Dying,[1] was an extinction event that occurred 251.4 Ma (million years ago),[2][3] forming the boundary between the Permian and Triassic geologic periods. It was the Earth's most severe extinction event, with up to 96% of all marine species[4] and 70% of terrestrial vertebrate species becoming extinct[5] It is the only known mass extinction of insects.[6][7] Some 57% of all families and 83% of all genera were killed. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after other extinction events.[4] This event has been described as the "mother of all mass extinctions."[8]

Researchers have variously suggested that there were from one to three distinct pulses, or phases, of extinction.[2][5][9][10] There are several proposed mechanisms for the extinctions; the earlier phase was likely due to gradual environmental change, while the latter phase has been argued to be due to a catastrophic event. Suggested mechanisms for the latter include large or multiple bolide impact events, increased volcanism, and sudden release of methane clathrate from the sea floor; gradual changes include sea-level change, anoxia, increasing aridity, and a shift in ocean circulation driven by climate change.[11]

Until 2000, it was thought that rock sequences spanning the Permian-Triassic boundary were too few and contained too many gaps for scientists to reliably determine its details.[15] However, a study of uranium/lead ratios of zircons from rock sequences near Meishan in Changxing County of Zhejiang Province, China[3] date the extinction to 251.4 ± 0.03 Ma, with an ongoing elevated extinction rate occurring for some time thereafter.[2] A large ( approximately 9‰), abrupt global decrease in the ratio of 13C to 12C, coincides with this extinction, and is sometimes used to identify the Permian-Triassic boundary in rocks that are unsuitable for radiometric dating.[20] Further evidence for environmental change around the P-Tr boundary suggests an 8 °C (14.40 °F) rise in temperature,[13] and an increase in CO2 levels by 2000ppm (by contrast, the concentration immediately before the industrial revolution was 280ppm).[13] There is also evidence of increased ultraviolet radiation reaching the earth, and causing the mutation of plant spores.[13]

Marine invertebrates suffered the greatest losses during the P–Tr extinction. In the intensively-sampled south China sections at the P-Tr boundary, for instance, 286 out of 329 marine invertebrate genera disappear within the final 2 sedimentary zones containing conodonts from the Permian.[2]

Statistical analysis of marine losses at the end of the Permian suggests that the decrease in diversity was caused by a sharp increase in extinctions instead of a decrease in speciation.[38] The extinction primarily affected organisms with calcium carbonate skeletons, especially those reliant on ambient CO2 levels to produce their skeletons.[39]

Among benthic organisms, the extinction event multiplied background extinction rates, and therefore caused most damage to taxa that had a high background extinction rate (by implication, taxa with a high turnover).[40][41] The extinction rate of marine organisms was catastrophic.[2][8][42][43]

The groups with the highest survival rates generally had active control of circulation, elaborate gas exchange mechanisms, and light calcification; more heavily calcified organisms with simpler breathing apparatus were the worst hit.[12][44] In the case of the brachiopods at least, surviving taxa were generally small, rare members of a diverse community.[45]

The Permian had great diversity in insect and other invertebrate species, including the largest insects ever to have existed. The end-Permian is the only known mass extinction of insects,[6] with eight or nine insect orders becoming extinct and ten more greatly reduced in diversity. Palaeodictyopteroids (insects with piercing and sucking mouthparts) began to decline during the mid-Permian; these extinctions have been linked to a change in flora. The greatest decline, however, occurred in the Late Permian and were probably not directly caused by weather-related floral transitions.[8]

Interestingly, plants are relatively immune to mass extinction, with the impact of all the major mass extinctions "negligible" at a family level.[[13] However, a massive rearrangement of ecosystems does occur, with plant abundances and distributions changing profoundly;[13] the Palaeozoic flora scarcely survived this extinction.[48]

[edit] Possible explanations of these patterns

The most vulnerable marine organisms were those that produced calcareous hard parts (i.e., from calcium carbonate) and had low metabolic rates and weak respiratory systems—notably calcareous sponges, rugose and tabulate corals, calciate brachiopods, bryozoans, and echinoderms; about 81% of such genera became extinct. Close relatives without calcareous hard parts suffered only minor losses, for example sea anemones, from which modern corals evolved. Animals with high metabolic rates, well-developed respiratory systems, and non-calcareous hard parts had negligible losses—except for conodonts, in which 33% of genera died out.[55]

This pattern is consistent with what is known about the effects of hypoxia, a shortage but not a total absence of oxygen. However, hypoxia cannot have been the only killing mechanism for marine organisms. Nearly all of the continental shelf waters would have had to become severely hypoxic to account for the magnitude of the extinction, but such a catastrophe would make it difficult to explain the very selective pattern of the extinction. Models of the Late Permian and Early Triassic atmospheres show a significant but protracted decline in atmospheric oxygen levels, with no acceleration near the P-Tr boundary. Minimum atmospheric oxygen levels in the Early Triassic are never less than present day levels—the decline in oxygen levels does not match the temporal pattern of the extinction.[55]

The observed pattern of marine extinctions is also consistent with hypercapnia (excessive levels of carbon dioxide). Carbon dioxide (CO2) is actively toxic at above-normal concentrations, as it reduces the ability of respiratory pigments to oxygenate tissues, and makes body fluids more acidic, thereby hampering the production of carbonate hard parts like shells. At high concentrations, carbon dioxide causes narcosis (intoxication).[56] In addition to these direct effects, CO2 reduces the concentration of carbonates in water by "crowding them out," which further increases the difficulty of producing carbonate hard parts.

Marine organisms are more sensitive to changes in CO2 levels than are terrestrial organisms for a variety of reasons. CO2 is 28 times more soluble in water than is oxygen. Marine animals normally function with lower concentrations of CO2 in their bodies than land animals, as the removal of CO2 in air-breathing animals is impeded by the need for the gas to pass through the respiratory systems membranes (lungs, tracheae, and the like). In marine organisms, relatively modest but sustained increases in CO2 concentrations hamper the synthesis of proteins, reduce fertilization rates, and produce deformities in calcareous hard parts.[55] In addition, an increase in CO2 concentration leads to ocean acidification, consistent with the preferential extinction of heavily calcified taxa and signals in the rock record that suggest a more acidic ocean.[57]

There are several proposed mechanisms for the extinction event, including both catastrophic and gradualistic processes (similar to those theorized for the Cretaceous–Tertiary extinction event). The former include large or multiple bolide impact events, increased volcanism, or sudden release of methane hydrates from the sea floor. The latter include sea-level change, anoxia, and increasing aridity.[11] Any hypothesis about the cause must explain the selectivity of the event, which primarily affected organisms with calcium carbonate skeletons; the long (4–6 million year) period before recovery started; and the minimal extent of biological mineralization (despite inorganic carbonates being deposited) once the recovery began.[39]

The Emeishan and Siberian Traps eruptions may have caused dust clouds and acid aerosols—which would have blocked out sunlight and thus disrupted photosynthesis both on land and in the photic zone of the ocean, causing food chains to collapse. These eruptions may also have caused acid rain when the aerosols washed out of the atmosphere. This may have killed land plants and molluscs and planktonic organisms which had calcium carbonate shells. The eruptions would also have emitted carbon dioxide, causing global warming. When all of the dust clouds and aerosols washed out of the atmosphere, the excess carbon dioxide would have remained and the warming would have proceeded without any mitigating effects.[84]

The Siberian Traps had unusual features that made them even more dangerous. Pure flood basalts produce a lot of runny lava and do not hurl debris into the atmosphere. It appears, however, that 20% of the output of the Siberian Traps eruptions was pyroclastic, i.e. consisted of ash and other debris thrown high into the atmosphere, increasing the short-term cooling effect.[93] The basalt lava erupted or intruded into carbonate rocks and into sediments that were in the process of forming large coal beds, both of which would have emitted large amounts of carbon dioxide, leading to stronger global warming after the dust and aerosols settled.[84]

In January 2011, a team led by Stephen Grasby of the Geological Survey of Canada—Calgary, reported evidence that volcanism caused massive coal beds to ignite, possibly releasing more than 3 trillion tons of carbon. In a statement, Grasby said "In addition to these volcanoes causing fires through coal, the ash it spewed was highly toxic and was released in the land and water, potentially contributing to the worst extinction event in earth history."[96]

Other hypotheses include mass oceanic poisoning releasing vast amounts of CO2[101] and a long-term reorganisation of the global carbon cycle.[98]

There is evidence that the oceans became anoxic (severely deficient in oxygen) towards the end of the Permian. There was a noticeable and rapid onset of anoxic deposition in marine sediments around East Greenland near the end of the Permian.[108] The uranium/thorium ratios of several late Permian sediments indicate that the oceans were severely anoxic around the time of the extinction.[109]

This would have been devastating for marine life, producing widespread die-offs except for anaerobic bacteria inhabiting the sea-bottom mud. There is also evidence that anoxic events can cause catastrophic hydrogen sulfide emissions from the sea floor (see below).

The sequence of events leading to anoxic oceans might have involved a period of global warming that reduced the temperature gradient between the equator and the poles, which slowed or even stopped the thermohaline circulation. The slow-down or stoppage of the thermohaline circulation could have reduced the mixing of oxygen in the ocean.[109]

A severe anoxic event at the end of the Permian could have made sulfate-reducing bacteria the dominant force in oceanic ecosystems, causing vast emissions of hydrogen sulfide that poisoned plant and animal life on both land and sea, as well as severely weakening the ozone layer, exposing much of the life that remained to fatal levels of UV radiation.[111] Indeed, anaerobic photosynthesis by Chlorobiaceae (green sulfur bacteria), and its accompanying hydrogen sulfide emissions, occurred from the end-Permian into the early Triassic. The fact that this anaerobic photosynthesis persisted into the early Triassic is consistent with fossil evidence that the recovery from the Permian–Triassic extinction was remarkably slow.[112]

This theory has the advantage of explaining the mass extinction of plants, which ought otherwise to have thrived in an atmosphere with a high level of carbon dioxide. Fossil spores from the end-Permian further support the theory: many show deformities that could have been caused by ultraviolet radiation, which would have been more intense after hydrogen sulfide emissions weakened the ozone layer.

M] Combination of causes
Possible causes supported by strong evidence appear to describe a sequence of catastrophes, each one worse than the previous: the Siberian Traps eruptions were bad enough in their own right, but because they occurred near coal beds and the continental shelf, they also triggered very large releases of carbon dioxide and methane.[55] The resultant global warming may have caused perhaps the most severe anoxic event in the oceans' history: according to this theory, the oceans became so anoxic that anaerobic sulfur-reducing organisms dominated the chemistry of the oceans and caused massive emissions of toxic hydrogen sulfide.[55]
 
Location: Vancouver Island, Canada | Registered: September 30, 2001Reply With QuoteReport This Post
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Somewhere I read a "Press and Pulse" theory about the PTE-
In a nutshell, an environment under prolonged stress is subjected to an event that pushed the biosphere suddenly to the brink.
Evidence shows extended elevated CO2 from volcanic and related coal bed fires- The camel was heavy-

Worth considering as we continue pushing the systems out of balance.
 
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quote:
Originally posted by SUB:
Somewhere I read a "Press and Pulse" theory about the PTE-
In a nutshell, an environment under prolonged stress is subjected to an event that pushed the biosphere suddenly to the brink.
Evidence shows extended elevated CO2 from volcanic and related coal bed fires- The camel was heavy-

Worth considering as we continue pushing the systems out of balance.


Scientist are interested to find out just what happened and refer to these events as tipping points whereby the temps spiked to a new stabilization of much higher temperature in a matter of decades. Something like 6 degrees C.

A leading theory involves the release of methane deposits (methane cathrates)out of the oceans as they warmed. did the oceans just warm or did ocean currents change? scientists are not positive of the mechanisms involved. Johnny's post in the AGW thread shows the direction of some of the research involved now in trying to track this down


21 years off the grid and counting

 
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There is strong evidence that a combination of low oxygen and high CO2 levels in the oceans were instrumental to the observed near complete elimination of life in the oceans- likely leading to H2S production which could explain the high extinction rates amongst plants which should otherwise have thrived in a CO2 rich environment.
 
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-AOA is a situation linked with everything, in ways we don't fully comprehend- but also separate from AGW.
If there were a cooling trend, with elevated CO2, the cooler water would be able to hold CO2 more easily.
Consequences?
We don't know.
 
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"Finally, it should be emphasized that the historical record associated with previous incidents of ocean acidification and calcifying species may be a foreboding portent. The mass extinction of huge numbers of calcifying marine species 55 million years ago (the Paleocene-Eocene Thermal Maximum) may have been largely attributable to ocean acidification and associated carbonate undersaturation. Moreover, it took over 110,000 years for calcium carbonate levels to return to previous levels. Because the release of carbon was more gradual during this era, facilitating some buffering by deep sea carbonate dissolution, it is likely that contemporaneous acidification will be more “rapid and intense,” says the European Science Foundation."

http://www.terrain.org/articles/21/burns.htm
 
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It seems to me that ocean acidification is a chemistry issue, but so far everything you've presented has been evidence from the fossil and geological records that imply ocean acidification. Has there been a controlled experiment proving the chemistry?
 
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Third post on this thread-

Two extinction events where acididic oceans seem to be a factor.
Excess CO2 causes the oceans' Ph to lower.
Yes, it is chemistry.

P/T Event:

The observed pattern of marine extinctions is also consistent with hypercapnia (excessive levels of carbon dioxide). Carbon dioxide (CO2) is actively toxic at above-normal concentrations, as it reduces the ability of respiratory pigments to oxygenate tissues, and makes body fluids more acidic, thereby hampering the production of carbonate hard parts like shells. At high concentrations, carbon dioxide causes narcosis (intoxication).[56] In addition to these direct effects, CO2 reduces the concentration of carbonates in water by "crowding them out," which further increases the difficulty of producing carbonate hard parts.

Marine organisms are more sensitive to changes in CO2 levels than are terrestrial organisms for a variety of reasons. CO2 is 28 times more soluble in water than is oxygen. Marine animals normally function with lower concentrations of CO2 in their bodies than land animals, as the removal of CO2 in air-breathing animals is impeded by the need for the gas to pass through the respiratory systems membranes (lungs, tracheae, and the like). In marine organisms, relatively modest but sustained increases in CO2 concentrations hamper the synthesis of proteins, reduce fertilization rates, and produce deformities in calcareous hard parts.[55] In addition, an increase in CO2 concentration leads to ocean acidification, consistent with the preferential extinction of heavily calcified taxa and signals in the rock record that suggest a more acidic ocean.[57]
 
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Originally posted by RickDaTech:
It seems to me that ocean acidification is a chemistry issue, but so far everything you've presented has been evidence from the fossil and geological records that imply ocean acidification. Has there been a controlled experiment proving the chemistry?


-A chemistry primer for AOA:

Ocean Acidification is, as its name suggests, a lowering of the pH of the ocean water. This is caused by the dissolution and reaction of carbon dioxide (CO2) into water; this process is often used in manufacture of soft drinks to create a fizzy, acidic taste. However, as one may suspect, a clam living in a pool filled with soda is unlikely to live comfortably. Though the gradually increasing acidity of the ocean is not of the same level of soft drinks, the acidification of the ocean still causes problems as the marine environment becomes changes.

Normally, the ocean is involved in the carbon cycle, where it acts as a sink and stores a large percentage of the Earth's total carbon. As the atmosphere and the ocean make contact with one another, CO2 is transferred between the two, particularly from the atmosphere to the ocean's surface until the two reach equilibrium, which can take up to a year to complete ( Doney et. al 2008).

When atmospheric CO2 dissolves into the ocean, it reacts with water through a series of steps to form HCO3-, or bicarbonate ion:


CO2 + H2O à H2CO3 Carbonic Acid
H2CO3 ↔ H+ + HCO3- Bicarbonate ion
HCO3- ↔ H+ + CO32- Carbonate ion



In the ocean, about 90% of all inorganic carbon is in the bicarbonate state (HCO3-), with 9% as the carbonate ion (CO32-) and the last 1% as dissolved CO2 (Doney et. al 2008).

However, as concentration of atmospheric CO2 increases, more is absorbed into the ocean, which pushes the reaction towards the end result of the CO32- and then, as it reacts again to the multitude of available hydrogen ions, back to the HCO3- state (Feely et. al 2004).

Compared with preindustrial amounts of [CO32-], with the assumption that alkalinity fields were identical to modern times, it was found that the introduction of data-based anthropogenic CO2 has caused a decrease in [CO32-] by more than 10%; the same results were found when using simulated CO2 from the Ocean Carbon-Cycle Model Intercomparison Project (Orr et. al 2005).

The increase in CO2 also over time increases the number of H+ ions in the water and decreases the pH. With the ocean taking in roughly one third of all human generated carbon dioxide, the amount of ions has increased, resulting in a pH drop of roughly 0.1, or 25% increase in protons; it is estimated that the pH will continue to drop to 0.3-0.5 by 2100 (Jackson 2010).

Normally, many ocean species take in carbonate ions to form calcium carbonate, from which the calcium is available from dissolved minerals and sediments in the ocean:


Ca2+ + CO32- à CaCO3 Calcium carbonate



Calcium carbonate (CaCO3) is used for the formation of structures in many marine invertebrates, including mollusks and corals. However, CaCO3 also reacts with CO2:


CO2 + CaCO3 + H2O à 2HCO3- + Ca2+ Bicarbonate ion and calcium ion



With these reactions, the end result is that more 2HCO3-, the bicarbonate ion, is formed and less carbonate becomes available for use for these marine organisms to use. At the same time, with more protons (H+) prevalent in the water, the pH decreases and acidity of the water increases. In the end, the water changes to become an environment that many organisms may have trouble adjusting to, while at the same time diminishing the amount of resources they need in order to build their body structures.





Sources:

Feely, R.A. (2004). "Impact of Anthropogenic CO2 on the CaCO3 System in the Oceans". Science: Vol. 305. pp 362-366.

Jackson, Robert. (2010). Biology 217 Lecture: Ecology and Global Change (9 February 2010). Duke University.

Orr, J.C. (2005). "Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms". Nature: Vol. 437. pp 681-686.

Doney, S.C. (2008). "Ocean Acidification: The Other CO2 problem". Annual Review of Marine Science: Vol. 1. pp 169-192.



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Location: Vancouver Island, Canada | Registered: September 30, 2001Reply With QuoteReport This Post
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The evidence keeps piling up that carbon cycle imbalances correlate with at least two mass extinction events.

To the skeptic PMing me:
Indeed, it is sage to be wary of unfounded gossip, hearsay, propaganda and advertising....
but:
The burden of scientific proof that Oceanic Acidification is currently caused by humans and real is very well satisfied.
I encourage the Heartland Institute and any other contenders to mount a credible campaign to counter this fact.
 
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Perhaps an Anthropocentric Climate/Habitat Destruction Ethics thread is required-
 
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While concerns over ocean acidification are not new, a recent study provides more concrete evidence than ever before that the process has already begun. Australian scientists found that shells of the microscopic, amoeba-like organisms called foraminifera, which exist by the billions in oceans around the world, have become significantly thinner since the Industrial Revolution.
The study, published in Nature Geoscience, is the first to look specifically at acidification and pin it to greenhouse-gas pollution, which is driven especially by the invisible product of burning oil, gas and coal. “It is the invasion of anthropogenic (man-made) CO2 that is causing this particular source of acidification,” said co-author William Howard [AFP].
The research team compared newer shells of Globigerina bulloides, a species of foraminifera, with shells of the same species that had sunk hundreds of years earlier; the modern shells were found to be 30 to 35 percent lighter than older specimens of about the same size. The older shells predate the industrial age, when CO2 levels started rising and the acidity of the ocean, caused by the absorption of the gas, began to increase…. As ocean acidity increases, the saturation levels of carbonate minerals in the water decreases, making it more difficult for organisms to precipitate out the carbonate for their shells [The New York Times].
Foraminifera are an important part of the ecological chain and also provide a bulwark against global warming. They transform carbon dioxide (CO2) from the air into calcium-based shells. When they die, their carbon-rich shells sink to the ocean floor, effectively storing the atmospheric CO2 forever…. If the loss of shell mass threatens the survival of the amoeba-like creatures, it could also disrupt a food chain reaching from the plankton they eat, all the way up to large sea mammal such as whales [AFP]. Though scientists have only recently begun to study ocean acidification, they worry about its potential to disrupt the earth’s carbon cycle, and are also concerned that because it occurs on such a large scale efforts to reverse the trend are not likely to be effective in the short-term.
Already, ocean acidity has increased about 32% since pre-industrial times. By 2100, it is projected to have increased by perhaps 130%, which scientists fear could have a potentially catastrophic impact on marine life [BBC]. “If forams and other shell makers are not making shells, that might change the transfer of carbon from the surface ocean into the deep ocean,” said Howard. “It changes the efficiency of the biological pump, and would tend to lessen the degree to which the ocean takes up carbon [AFP].
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Image: William Howard
 
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And we now can distinguish between ancient and active carbon:

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News | Environment


Ocean Acidification Hits Great Barrier Reef
Coral growth has been sluggish since 1990 due to an increase in both sea temperature and acidity as a result of global warming
By David Biello | January 1, 2009 | 12
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REEFER SADNESS: Massive Porites coral, like the one pictured here, in the Great Barrier Reef are not growing as much anymore, most likely because of warmer and more acidic seawater.
Image: Courtesy of Jurgen Freund of Freund Factory
The largest coral reef system in the world—and the biggest sign of life on Earth, visible from space—is not growing like it used to. A sampling of 328 massive Porites coral (large structures resembling brains that are formed by tiny polyps) from across the 133,000-square-mile (344,000-square-kilometer) reef reveals that growth of these colonies has slowed by roughly 13 percent since 1990.

The most likely reason is climate change caused by increasing carbon dioxide (CO2) and other greenhouse gases in the atmosphere, according to a new paper published today in Science.

The burning of fossil fuels over the past century or so has driven atmospheric CO2 levels from 280 parts per million (ppm) to 387 ppm—and growing. More than 25 percent of this extra CO2 is absorbed by the world's oceans and reacts with seawater to form carbonic acid. A rising carbonic acid level means a more acidic ocean.

And a more acidic ocean is bad news for coral and other sea creatures, which form their shells from calcium carbonate they extract from seawater. The more acidic the water, the more difficult it is to build the shells in the first place—as well as keeping them from dissolving.

To probe how corals are faring, marine biologist Glenn De'ath and colleagues at the Australian Institute of Marine Science in Townsville, Queensland, examined Porites coral samples stretching as far back as 1572. Because Porites lay down annual layers—like tree rings—changing environmental conditions are etched into their skeletons.
The record has not been good in recent years: Since 1990 coral have been extending and thickening by less and less each year. "The data suggest that such a severe and sudden decline in calcification is unprecedented in at least the past 400 years," the researchers wrote.

"This study put all this worry and discussion [about ocean acidification] into a real-world context," says marine biologist John Bruno of the University of North Carolina at Chapel Hill. "It shows that coral growth is indeed slowing—over a huge range and at many reefs—potentially due to increased acidity."

Slower growth will mean both that existing coral will find it difficult to cope with escalating acidity and rising sea levels. This will have enormous knock-on effects in sea life that relies on coral reefs for habitat—as well as human fisheries and other ecosystem services.

In the meantime, it appears that changes in sea temperatures and increased acidity are already beginning to impact the Great Barrier Reef. "Our data show that growth and calcification of massive Porites in the Great Barrier Reef are already declining and are doing so at a rate unprecedented in coral records reaching back 400 years," the researchers wrote. "These organisms are central to the formation and function of ecosystems and food webs, and precipitous changes in the biodiversity and productivity of the world's oceans may be imminent."
 
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To find a period analogous to the present, you have to go back at least 55 million years, to what's known as the Paleocene-Eocene Thermal Maximum or PETM. During the PETM huge quantities of carbon were released into the atmosphere, from where, no one is quite sure. Temperatures around the world soared by around ten degrees Fahrenheit, and marine chemistry changed dramatically. The ocean depths became so corrosive that in many places shells stopped piling up on the seafloor and simply dissolved. In sediment cores the period shows up as a layer of red clay sandwiched between two white layers of calcium carbonate. Many deepwater species of forami­nifera went extinct.

Surprisingly, though, most organisms that live near the sea surface seem to have come through the PETM just fine. Perhaps marine life is more resilient than the results from places like Castello Aragonese and One Tree Island seem to indicate. Or perhaps the PETM, while extreme, was not as extreme as what's happening today.

The sediment record doesn't reveal how fast the PETM carbon release occurred. But modeling studies suggest it took place over thousands of years—slow enough for the chemical effects to spread through the entire ocean to its depths. Today's rate of emissions seems to be roughly ten times as fast, and there's not enough time for the water layers to mix. In the coming century acidification will be concentrated near the surface, where most marine calcifiers and all tropical corals reside. "What we're doing now is quite geologically special," says climate scientist Andy Ridgwell of the University of Bristol, who has modeled the PETM ocean.

Just how special is up to us. It's still possible to avert the most extreme acidification scenarios. But the only way to do this, or at least the only way anyone has come up with so far, is to dramatically reduce CO2 emissions. At the moment, corals and pteropods are lined up against a global economy built on cheap fossil fuels. It's not a fair fight.
 
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So, you're suggesting that the most selfish and narcissistic species on the planet today, and likely the most selfish and narcissistic species since the Velociraptors that existed from 71 to 75 million years ago, should stop using fossil fuels because it might acidify the shallow parts of the ocean? ...and, as if that wasn't bad enough, you've decided that nuclear power, the only viable substitute which might possibly displace fossil fuels to maintain the lifestyle that 6 billion humans desire above all else, can't be used either.

I can see why BC's largest agricultural export is so popular; it no doubt makes delusional thinking seem real.

Humans have never stopped using anything until it's gone or they found something to replace it. There's not a 'hope-in-hell' that humans will do anything to stop the inevitable race to extinction for themselves and many of the other species on the planet. Sure, a few individuals like you and I will significantly reduce their impact on the planet, but those few are but a drop in the bucket and will never make any difference in the grand scheme of things.

Unless there is a plague that decimates the human population, the human race is doomed to extinction, just like the Velociraptors. We're simply not intelligent enough to survive.



 
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