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The Ocean Acid Problem

by technopolitical Wed Oct 11th, 2006 at 04:56:27 AM EST

There's more to the CO2 problem than warmth and weather. It's making the World Ocean more acidic, and ocean ecosystems are on track to be disrupted in ways that no one predict. With enough acid, shells and coral will dissolve.



Washington Post: Growing Acidity of Oceans May Kill Corals

The escalating level of carbon dioxide in the atmosphere is making the world's oceans more acidic, government and independent scientists say. They warn that, by the end of the century, the trend could decimate coral reefs and creatures that underpin the sea's food web.

Although scientists and some politicians have just begun to focus on the question of ocean acidification, they describe it as one of the most pressing environmental threats facing Earth.

"It's just been an absolute time bomb that's gone off both in the scientific community and, ultimately, in our public policymaking," said Rep. Jay Inslee (D-Wash.)...

The pH level, measured in "units," is a calculation of the balance of a liquid's acidity and its alkalinity. The lower a liquid's pH number, the higher its acidity; the higher the number, the more alkaline it is. The pH level for the world's oceans was stable between 1000 and 1800, but has dropped one-tenth of a unit since the Industrial Revolution, according to Christopher Langdon, a University of Miami marine biology professor.

Scientists expect ocean pH levels to drop by another 0.3 units by 2100, which could seriously damage marine creatures that need calcium carbonate to build their shells and skeletons. Once absorbed in seawater, carbon dioxide forms carbonic acid and lowers ocean pH, making it harder for corals, plankton and tiny marine snails (called pteropods) to form their body parts.

Ken Caldeira, a chemical oceanographer at Stanford University who briefed lawmakers along with NCAR marine ecologist Joan Kleypas, said oceans are [¶] more acidic than they have has [sic] been for "many millions of years."

[¶ The reporter got this wrong: pH would reach this level in 2100, if atmospheric CO2 concentrations were to increase unchecked.]

For a more reliable source than the above WaPo article, see:
Ocean acidification due to increasing atmospheric carbon dioxide (PDF, 1 MB)
(Royal  Society, June 2005)

From what I've read, the process of ocean acidification is easier to model than climate change. Subject to various modulating influences, the effects of ocean circulation, and so forth, the basic story is that CO2 dissolves in water, forms carbonic acid, and lowers pH. Other influences make the story more complex, but nothing like climate change: acidification isn't nearly as sensitive to unknown forces, counter-forces, feedback loops, and messy, swirling weather patterns.

The effects of ocean acidification, however, seem less predictable than those of climate change.

Climate change, after all, is business-as-usual for Earth. Some regions become warmer, but most become no warmer than neighboring regions had been before. On the whole, species shift their ranges toward the poles, while polar bears shift their ranges northward past the pole and into the afterlife. Some regions become wetter or drier, but there have always been wet and dry places. Maybe the Gulf Stream shifts and Europe freezes, but little matter -- global climate has seen far greater changes in the last 20,000 years. By some standards (e.g., human) the expected disruptions may be enormous and unpredictable, but by other standards (e.g., planetary deep time), they're minor.

Now consider ocean acidification: On a planetary time scale, CO2 concentrations have sometimes been far higher than the highest projections for the next century, but this didn't make the seas more acid. Changes were slow and calcium carbonate minerals have always dissolved fast enough to buffer the ocean's chemistry. This process stabilized pH and kept calcium carbonate levels at saturation. Organisms (plankton, giant clams, coral...) could build up shells of calcium carbonate and not have them dissolve away instead.

Today, however, the atmospheric CO2 is rising far faster, too fast for calcium carbonate dissolution to keep up. The oceans are therefore on their way to being more acidic than they've been for... well... Caldeira simply says "many millions of years."

Note the difference: This is the whole ocean shifting outside its prior range. The analogy in the climatic case would be if all the temperature zones now on Earth shifted toward the poles and disappeared, leaving the whole world hotter than equatorial regions are today. And unlike the problem of rising global mean temperature, this one doesn't seem to have a cheap, easy fix.

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Words and ideas I offer here may be used freely and without attribution.
by technopolitical on Wed Oct 11th, 2006 at 04:57:36 AM EST
...got more things wrong, but let's not squibble on that too much.

The Royal Society phrases it right: acidification.

This:

The escalating level of carbon dioxide in the atmosphere is making the world's oceans more acidic.

is incorrect. The increasing cabon dioxide makes the oceans less alakine, it has not been acidic (= below pH 7) in a long time. Ocean pH is now measured at about 8.1 (quoted from head, so could be mistaken there).

But well. That's what reporters do. The problem of decreasing pH appears real enough.

by Nomad on Wed Oct 11th, 2006 at 07:44:30 AM EST
alakine = alkaline
by Nomad on Wed Oct 11th, 2006 at 07:45:46 AM EST
[ Parent ]
Let's have a PN duel...

You've said that before, and I fail to be convinced even the second time.

pH measures the concentration of H+ ions, that is, the acidity.

pOH measures the concentration of OH- ions, that is, the basicity.

pH + pOH = 14

You're taking the ph of pure water (pH = 7) as your boundary between "acid" and "basic". That is an arbitrary choice and depends on a medium (pure water) that is not found outside the laboratory. Sea-living organisms in pH = 7 would esperience it as an acidic environment, since they are adapted to a pH of 8.1 (by your claim).

Also, the process is one of increased concentration of carbonic acid in the water.  That is not the same thing as the removal of some basic substance (say ammonia). So it is still more descriptive to call it acidification than de-basification.

Those whom the Gods wish to destroy They first make mad. -- Euripides

by Migeru (migeru at eurotrib dot com) on Wed Oct 11th, 2006 at 07:51:43 AM EST
[ Parent ]
Oh, and pH = 7 is the pH of pure water in "standard conditions of pressure and temperature" (1 Atm, 25°C), also not found outside a textbook.

Those whom the Gods wish to destroy They first make mad. -- Euripides
by Migeru (migeru at eurotrib dot com) on Wed Oct 11th, 2006 at 08:04:18 AM EST
[ Parent ]
You're taking the ph of pure water (pH = 7) as your boundary between "acid" and "basic". That is an arbitrary choice and depends on a medium (pure water) that is not found outside the laboratory. Sea-living organisms in pH = 7 would esperience it as an acidic environment, since they are adapted to a pH of 8.1 (by your claim).

There's no answer I could possibly provide you here. Where are you going for with this? The pH of 7 as watershed is a chosen standard, and really only somewhat arbitrary because it is the natural state of pure water by its dissociation behaviour.

The descriptor that sea-living organism would experience a pH of 7 as acidic, is simply the incorrect use of the definitions. They would experience it as less alkaline, or neutral. Would the pH drop below 7, then they would experience an acidic environment. It's just language, semantics. When I read that article, I read a language that simply doesn't make sense to me, knowing that ocean pH hovers at about 8.1. It's actually a futile point anyway, because what really matters is the change in the equilibrium reaction between carbonate (CO3), CO2 and bicarbonate (HCO3) which directly affect the dissolution of calcoimcarbonate shells.

I've no qualms to describe the process as acidification, and I've even done so in my previous post by stating that the Royal Society's use of acidification is perfectly correct. Because that's what it is: the lowering of pH in water.

by Nomad on Wed Oct 11th, 2006 at 06:43:41 PM EST
[ Parent ]
To be picky about pH, it really can't be the case that when OH- and H+ have equal concentrations, the log is 7.000000000000 (in units of moles/liter, no less). Looking into this, I found that the Wikipedia article on pH first makes the usual, impossible statement

In solution at 25 °C, a pH of 7 indicates neutrality (i.e. the pH of pure water) because water naturally dissociates into H+ and OH− ions with equal concentrations of 1×10−7 mol/L.

then later says that the actual number, at 25°C, is 6.998 ± 0.001. So, you see, when a solution is a pH 7, it's actually acid. Beware!

Words and ideas I offer here may be used freely and without attribution.
by technopolitical on Wed Oct 11th, 2006 at 07:14:30 PM EST
[ Parent ]
But I think you mean basic? :)
by Nomad on Wed Oct 11th, 2006 at 07:42:50 PM EST
[ Parent ]
Hey, it's only 0.002 ± 0.001 pH units away from the threshold of being acid! You call that significant?
[[Ooops.]]

Words and ideas I offer here may be used freely and without attribution.
by technopolitical on Thu Oct 12th, 2006 at 12:57:38 AM EST
[ Parent ]
Does this acidification have any relevance for, say, the Ca/Mg ratios of foraminifera shells?

The fact is that what we're experiencing right now is a top-down disaster. -Paul Krugman
by dvx (dvx.clt št gmail dotcom) on Wed Oct 11th, 2006 at 09:01:08 AM EST
[ Parent ]
I don't know. Something to consider, dvx.
by Nomad on Wed Oct 11th, 2006 at 07:11:14 PM EST
[ Parent ]
If you have a solution of calcium carbonate and magnesium carbonate and you add carbonate ions, you change the concentration of the Ca and Mg ions by an amount which depends on the eqquilibrium constants of the respective precipitation/solution rections.

That is, the solubility of Mg and Ca will change differently as CO2 dissolvess in water, and you have told us that foraminifera amplify the differences in solubility.

Those whom the Gods wish to destroy They first make mad. -- Euripides

by Migeru (migeru at eurotrib dot com) on Wed Oct 11th, 2006 at 07:21:03 PM EST
[ Parent ]
Since Ca and Mg have the same valence, the solubilities change by the same multiplicative factor, as the product of the concentration of the metal and the Carbonate must be constant (at constant temperature and pressure).

Those whom the Gods wish to destroy They first make mad. -- Euripides
by Migeru (migeru at eurotrib dot com) on Thu Oct 12th, 2006 at 08:55:39 AM EST
[ Parent ]
I agree with your taste in words here, but only somewhat.

As Migeru notes, pH 7 is somewhat arbitrary.

But of course it's not entirely arbitrary -- a condition with equal concentrations of H+ and OH-, with their sum at a minimum, is a special point.

But "7" only approximates this point, and many chemistry texts lie about that.

But also, many processes are sensitive not to the balance of the two, but to the concentration of one, and each varies smoothly with no discontinuity or change of sign at pH 7, which is why pH is defined in terms only of the concentration of H+.

But "more acidic" implies that the state is already in the "acid" range, which it certainly isn't.

But "acid" is, just discussed, physically arbitrary.

But it's standard usage.

But even the term "acidification" would seem to mean making acid, which isn't a prospect.

But "dealkalinification" would do the job.

But that would be pedantic, and the discussion, once it's out of the journals, is aimed at public understanding, and above or below pH 7 is beside the point.

But what about Lewis acids -- should Brønsted acidity get all the attention?

But "but" is a fun conjunction to abuse.

But "in conjunction with" means roughly the same as "and".
-------------------------

There is a need to fill slots in sentences like "Because there is more CO2, the oceans are becoming more ___", and this encourages the use of "more acidic", despite its faults.

If the issue gets into popular culture, you know that he cartoons will show the oceans burning people, dissolving boats, and so on. The oceans will be about to become "acid".

Words and ideas I offer here may be used freely and without attribution.

by technopolitical on Wed Oct 11th, 2006 at 03:07:15 PM EST
[ Parent ]
are completely right. With every textbook we open, we find simplifications, which need to be replaced by more sophisticated simplifications when we decide to dig deeper. And again. And again. Until your sentences becomes so turgid, no one reads your articles and you die poor and unread and everyone forgets about you, so what's the point?

But as above, I do not argue against the use of "acidification". I argue against the frequent (actually, I've hardly seen it anywhere right in press articles so far) use of "turning the oceans more acidic". That's just flat out incorrect, and although I understand the need for public understanding, this is mythmaking at work - which I resent. And here's an audience which is willing to be open for the slight correction here and there.

by Nomad on Wed Oct 11th, 2006 at 06:59:05 PM EST
[ Parent ]
I would rather go back to foraminifera.

Those whom the Gods wish to destroy They first make mad. -- Euripides
by Migeru (migeru at eurotrib dot com) on Wed Oct 11th, 2006 at 07:01:29 PM EST
[ Parent ]
We're nearing another Friday, yes? Real life has kept me off the streets. Actually, on the street, and off the keyboards the last days.
by Nomad on Wed Oct 11th, 2006 at 07:07:50 PM EST
[ Parent ]
But I'm the one offering an argument against "acidification"!
But I agree with you anyway.

Words and ideas I offer here may be used freely and without attribution.
by technopolitical on Thu Oct 12th, 2006 at 12:59:49 AM EST
[ Parent ]
The problem with articles like this is that they ignore evolution. Changing the pH of the oceans will affect organisms now existing, but we cannot foresee how they will adapt. For example creatures with a lot of calcium in their structure might start including silicon or carbon. Even in the present ocean we see some strange adaptions such as those near sulfur laden vents.

So the best that can be said is that adding more CO2 to the oceans will change the ecosystem.

Policies not Politics
---- Daily Landscape

by rdf (robert.feinman@gmail.com) on Wed Oct 11th, 2006 at 10:53:39 AM EST
they ignore evolution

Not entirely the same of course, but most climate-change articles I've read that do mention evolution suggest that climate change is happening too fast for species to adapt in an (for want of a better word) orderly fashion, i.e. without drastic die-backs.

In this connection, fact that acidification is occurring to a measurable extent must at least (imo) be cause for concern.

The fact is that what we're experiencing right now is a top-down disaster. -Paul Krugman

by dvx (dvx.clt št gmail dotcom) on Wed Oct 11th, 2006 at 11:14:48 AM EST
[ Parent ]
It is a matter of time scales. The question is how much the conditions are changing over each generation, or how many generations are encompassed by the characteristic time scale of the changes.

Bacteria who are able to reproduce every 30 minutes have it easier than species that have one generation every 30 years.

Those whom the Gods wish to destroy They first make mad. -- Euripides

by Migeru (migeru at eurotrib dot com) on Wed Oct 11th, 2006 at 11:16:53 AM EST
[ Parent ]
Bacteria who are able to reproduce every 30 minutes have it easier than species that have one generation every 30 years.

This reminds me of Stephen Jay Gould.

PROGRESS DOES NOT RULE (and is not even a primary thrust of ) the evolutionary process. For reasons of chemistry and physics, life arises next to the "left wall" of its simplest conceivable and preservable complexity. This style of life (bacterial) has remained most common and most successful. A few creatures occasionally move to the right, thus extending the right tail in the distribution of complexity. Many always move to the left, but they are absorbed within space already occupied. Note that the bacterial mode has never changed in position, but just grown higher.


Don't fight forces, use them R. Buckminster Fuller.
by rg (leopold dot lepster at google mail dot com) on Wed Oct 11th, 2006 at 11:40:27 AM EST
[ Parent ]
the greater ability of simpler life forms to adapt quickly to our collective vandalism of atmosphere, water, and climate surely seems like one (among many) reason for the devolution of the oceanic food chain to earlier and more primitive (simpler and shorter lived) life forms:

In many places -- the atolls of the Pacific, the shrimp beds of the Eastern Seaboard, the fiords of Norway -- some of the most advanced forms of ocean life are struggling to survive while the most primitive are thriving and spreading. Fish, corals and marine mammals are dying while algae, bacteria and jellyfish are growing unchecked. Where this pattern is most pronounced, scientists evoke a scenario of evolution running in reverse, returning to the primeval seas of hundreds of millions of years ago.

Jeremy B.C. Jackson, a marine ecologist and paleontologist at the Scripps Institution of Oceanography in La Jolla, says we are witnessing "the rise of slime."

For many years, it was assumed that the oceans were too vast for humanity to damage in any lasting way. "Man marks the Earth with ruin," wrote the 19th century poet Lord Byron. "His control stops with the shore."

Even in modern times, when oil spills, chemical discharges and other industrial accidents heightened awareness of man's capacity to injure sea life, the damage was often regarded as temporary.

But over time, the accumulation of environmental pressures has altered the basic chemistry of the seas.

The causes are varied, but collectively they have made the ocean more hospitable to primitive organisms by putting too much food into the water.

Industrial society is overdosing the oceans with basic nutrients -- the nitrogen, carbon, iron and phosphorous compounds that curl out of smokestacks and tailpipes, wash into the sea from fertilized lawns and cropland, seep out of septic tanks and gush from sewer pipes.

Modern industry and agriculture produce more fixed nitrogen -- fertilizer, essentially -- than all natural processes on land. Millions of tons of carbon dioxide and nitrogen oxide, produced by burning fossil fuels, enter the ocean every day.

These pollutants feed excessive growth of harmful algae and bacteria.

At the same time, overfishing and destruction of wetlands have diminished the competing sea life and natural buffers that once held the microbes and weeds in check.

The consequences are evident worldwide.

Off the coast of Sweden each summer, blooms of cyanobacteria turn the Baltic Sea into a stinking, yellow-brown slush that locals call "rhubarb soup." Dead fish bob in the surf. If people get too close, their eyes burn and they have trouble breathing.

[entire article very much worth reading, and very depressing]

Eurolanders may be experiencing this devolution as a plague of jellyfish

Destroying the coral nurseries in which the larger, more complex species hatch and feed as juveniles can only exacerbate the process....

the blog Shifting Baselines comments fairly frequently on the death-watch for the world's oceans, and the grim determination of the Corporate PRess to "Keep False Hope Alive" by running repetitive upbeat disinformation to camouflage the true extent of the problem -- or periodic alarmist op/eds which always conclude with some cheery Energy Fairy story about science saving us or it being "too soon to tell" what's really going on.

[What's really going on is exterminism, the conversion of all biotic complexity on earth into inedible monopoly counters, i.e. "money".]

He also comments perspicaciously on the phenomenon for which his site is named, i.e. that with the hypermobility of the cheap fossil fuel age comes a loss of human continuity in bioregions:  such a large percentage of people in most coastal areas are newcomers that they have no memory of even 10 years ago, let alone a generation ago, and thus no sense of the extent and rate of damage and loss in local biotic systems, watersheds, etc.  The baseline is constantly shifting:  beach closures become normal, fisheries disappear and condos sprout, food comes from further and further away... I live on Monterey Bay, once a thriving salmon and sardine fishery, and the fish in my local fresh-food market is airlifted (let's call it what it is, even if "the market" drives it rather than a government programme) in from the Philippines and Hawaii and VietNam -- but this is "perfectly normal" to a 20 y.o. college student who just moved here.

[The energy cost of this food airlift necessitated by the coring-out and liquidation of food resources closer to home will only get higher over time.]

The shifting baseline makes it very difficult to mobilise social/political action to preserve biotic resources from piracy and vandalism or to repair the damage, since everything looks "just fine" to the newcomers -- who may be a majority of the population and may well have relocated from someplace even more damaged.  The "things were better in my day" grumbling from old-timers will be dismissed as just that, nostalgic grumbling -- even if every word of it is an accurate accounting of possibly-irretrievable loss of carrying capacity.

[The glut of cheap fossil fuel in a social system appears to have effects strangely analogous to the effects of hypernutrition in a biotic system -- the defeat of checks and balances and runaway hypertrophism.  We know how the story ends for a pond or a yeast culture -- or an ocean.]

The difference between theory and practise in practise ...

by DeAnander (de_at_daclarke_dot_org) on Wed Oct 11th, 2006 at 04:35:26 PM EST
[ Parent ]
What's really going on is a mass extinction.

Those whom the Gods wish to destroy They first make mad. -- Euripides
by Migeru (migeru at eurotrib dot com) on Wed Oct 11th, 2006 at 04:38:54 PM EST
[ Parent ]
is earth a reform school for otherwise incorrigible souls?

'exterminism' is right.

as is the description of our rendering resources into inedible units of money.

jesus wept...

a runaway hypertrophism of lacrimary function...

what's feeding the yeast of stupidity is the medium of ignorance it greedily thrives in.

thanks for educating us with such highly -packed posts...

the diadem in et's crown

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

by melo (melometa4(at)gmail.com) on Thu Oct 12th, 2006 at 03:15:55 PM EST
[ Parent ]
The ocean is a tremendous carbon sink.

Oceanographers I've talked to are thinking that the changes in ocean temperature are too rapid for many species to adapt.  The acidification rate of the ocean may also be too rapid for adaptation of species.

At present carbon emissions from human activities continue to increase at a steep rate.  

Meanwhile, the increase in ocean temperature is speeding up the chemical processes of acidification.  This is ultimately bad news for critters with exoskeletons.

If the present acidification continues, at some point the ocean will fail as a carbon sink.  So the carbon will remain mostly in the atmosphere, creating a rather Venusian environment.

In this scenario, there's a tipping point that will be catastrophic unless drastic reduction of carbon emissions are undertaken.

by Plan9 on Fri Oct 13th, 2006 at 10:52:12 AM EST
[ Parent ]
Substantial changes in the composition of shells seem likely to require a large change, in evolutionary terms.

It is significant that freshwater snails have calcium carbonate shells and some tolerate a pH below 6.

Words and ideas I offer here may be used freely and without attribution.

by technopolitical on Wed Oct 11th, 2006 at 03:25:51 PM EST
[ Parent ]


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