The Coming Eco-pocalypse

If you missed Christopher Horner’s speech in Howell Hall last week, allow me to inform you that global warming, as a political issue, is dying. The poor economy is taking the focus off of the environment, the world has been in a cooling trend for about the last decade, and a series of emails were recently leaked from a leading climate research institute that cast doubt on the scientific evidence for global warming in the first place.

All of this has combined to take the wind out of the sails of those demanding we “do something” about global warming.

In spite of this, if Mr. Horner is correct, eco-alarmism is far from dead. The vested interests that hyped global warming alarmism, from coal companies to former (and current) communists to the town of Carrboro, will not pass silently into the night.

Polar bears may no longer be the poster child of eco-alarmism, but similarly charismatic fauna can readily be found. This time, coral reefs are the ones in danger due to the folly of man—not from global warming, but from ocean acidification, the next big eco-threat.

As CRDaily readers, you are already, generally speaking, among the most well-informed readers around, but a brief explanation of the science would, I think, be helpful (In any case, I hope it will make my Chemical Oceanography teacher happy).

This is basically how it works: carbon dioxide in the atmosphere (see figure 1.a), whether it is naturally occurring or emitted from your tail pipe, is in equilibrium with dissolved CO2 in the ocean (fig. 1.b). The more CO2 in the air, the greater the amount dissolved in the ocean (think of a 2-liter bottle of soda—let it equilibrate with the air long enough and it loses its fizz—in this case, the reverse would happen).

Carbon dioxide dissolved in water can combine with a water molecule to form carbonic acid (fig. 1.c). Carbonic acid, being an acid, has a tendency to dissociate with one or more of its hydrogen atoms (fig. 1.d and 1.e), increasing the acidity of the total solution (in this case, the ocean is the solution) and lowering its pH.

Figure 1. Carbon dioxide from the atmosphere equilibrates with dissolved carbon dioxide in the ocean

 

Acidity, for the non-science majors, is basically a measure of the concentration of protons (H+ ions) in solution compared to hydroxide ions (OH-). The acidity is usually reported as pH, the negative log of the proton concentration; lower pH means more acidic, and higher means a more basic solution.

If I’ve lost you, let me summarize: CO2 + H2O –>  carbonic acid (H2CO3), making the ocean more acidic, making life more difficult for corals, which require a more basic pH to survive.

However, ocean acidification due to carbon emissions may be less of a threat than some alarmists have suggested. As Mr. Horner pointed out, carbon dioxide levels have been much higher in the past (about ten times higher for much of the Mesozoic era), and the fossil evidence suggests that corals were still able to survive.

Also, if you were looking forward to bathing in a fizzy ocean, I’m sorry to disappoint you, but that’s probably not going to happen anytime soon, either. Atmospheric carbon is just not going to reach high enough levels anytime soon, although it is certainly fun to imagine (the fizz part, not the dead corals).

10 comments

  1. "a series of emails were recently leaked from a leading climate research institute that cast doubt on the scientific evidence for global warming in the first place."

    This is only true if you have a fairly poor understanding of science and/or listen to too much right-wing talk radio.

  2. Global warming as a political issue is not actually dying. It likely will not take on the form of "cap & trade," but it is certainly in the works in the Senate between Sens. Lieberman, Kerry, and Graham. Also, there was a piece on Politico the other day that argued that the health care bill will actually help the passage of a climate bill because it has given activists a time to refocus their efforts and work on strategy (amongst other points).

    Premise fail.

  3. ditto what __o_ said; though this has no impact on the status of AGW as a political issue, considering that popular science literacy is abysmal and right-wing talk media is in as high gear as ever. The CRU leaks were almost certainly timed to be an October Surprise for the Copenhagen talks, and will be remembered for a long time as "the scandal that got uncovered" and not "the scandal that got uncovered but then fell apart upon cursory examination"

    as to the content of the post, most of the science is correct, up until:
    "However, ocean acidification due to carbon emissions may be less of a threat than some alarmists have suggested. As Mr. Horner pointed out, carbon dioxide levels have been much higher in the past (about ten times higher for much of the Mesozoic era), and the fossil evidence suggests that corals were still able to survive."
    What this bit is ignoring is evolution. Organisms are adapted to their environments; when their environments change, they must re-adapt. However, adaptation is not an instantaneous process. Humans changing the environment faster than organisms can adapt (to said organisms' detriment or extinction) is a recurring theme in human/nonhuman ecological interactions, and ocean acidification & corals are no exception. A good paper to read is:
    "Coral Reefs under rapid climate change and ocean acidification" (Hoegh-Guldberg et al. 2007) http://www.sciencemag.org/cgi/content/full/318/58
    Some highlights:

    *"In addition to the absolute amount of change, the rate at which change occurs is critical to whether organisms and ecosystems will be able to adapt or accommodate to the new conditions … Given that recent and future rates of change [in temperature, though there is another statement to this effect re: pH in a bit] dwarf even those of the ice age transitions, when biology at specific locations changed dramatically, it is likely that these changes will exceed the capacity of most organisms to adapt."

    *"Many experimental studies have shown that a doubling of pre-industrial [CO2]atm to 560 ppm decreases coral calcification and growth by up to 40%" (Thus, the effects of acidification on coral is an observation, not merely an 'alarmist' prediction)

    In particular, pay attention to this paragraph:
    *"Geological studies report a notable gap in the fossil record of calcified organisms, including reef-building corals (14) and calcareous algae (15), during the early Triassic when [CO2]atm increased dramatically and reached levels at least five times as high as today's(16). Phylogenetic studies suggest that corals as a group survived the Permian-Triassic extinction event (14) but may have done so through forms lacking calcified skeletons (17, 18). Although Scleractinian (modern) corals arose in the mid-Triassic and lived under much higher [CO2]atm, there is no evidence that they lived in waters with low-carbonate mineral saturation. Knoll et al. succinctly state that 'it is the rapid, unbuffered increase in [CO2]atm and not its absolute values that causes important associated changes such as reduced [CO32–], pH, and carbonate saturation of sea water' (19). The rate of [CO2]atm change is critical given that modern genotypes and phenotypes of corals do not appear to have the capacity to adapt fast enough to sudden environmental change."

    Here is a paper that discusses the issues with an explicitly paleogeochemical perspective: http://www.cell.com/trends/ecology-evolution/abst

    It is also worth noting that corals are not the only things affected by ocean pH- iron concentration, for example, is lowered as the ocean acidifies (http://www.sciencemag.org/cgi/content/full/327/59… ) which in turn reduces the ability of photosynthesizers to effectively process carbon. In addition to these primary effects taken separately, you also have to consider the environment as a complex system, in which these effects interact and synergize, causing an amplification of individual and secondary, unforeseen consequences. Sound like new age hocus pocus? In that case I'll cite the influential climate change 'skeptic', Michael Crichton, not exactly a hippy flower child: http://www.michaelcrichton.net/speech-complexity….
    For a case study in another environmental arena, look up pesticide/trematode synergism in amphibian populations.

    Finally, the fizz. The ocean isn't going to fizz no matter how high CO2 levels get. CO2 is not a magickal fizz substance; fizzing occurs not when its concentration rises above a certain point, but when there is a disequilibrium between the liquid state and the gaseous state. Don't believe me? Take an unopened bottle of coke. CO2 levels in the bottle are as high as they ever will be… but there's no fizz. Now open it. The hiss you hear is the pressurized gas in the bottle escaping, and as a result the partial pressure of the CO2 inside drops. A formerly equilibrated system is now out of equilibrium, so as per le Chatlier's principle, the system approaches equilibrium by releasing dissolved CO2 to replace the gas that was lost… in other words, by fizzing. The oceans will only fizz if atmospheric CO2 rapidly _drops_.

    1. Re: fizziness. Good point. I hadn't heard that before, but it makes sense. I've taken chemical oceanography and several chemistry classes, so if we ever talked about that I must have slept through lecture that day. In my post, I was mainly just trying to be cute, though.

  4. *caveat: the effects of aciditiy on iron are still not settled and some studies have even found the reverse effect; my point re: non-coral effects of ocean acidification and complex ecosystemic interactions stands nontheless.

  5. SkepticalScience has a good post up now, by the author of one of the papers cited above: http://www.skepticalscience.com/Ocean-acid.html

    In particular:
    ——————————————————————————————————————————————-
    3. “Organisms like corals have been around for hundreds of millions of years, over which time atmospheric carbon dioxide has varied greatly. Therefore, we don't need to be concerned about ocean acidification.”
    The fact that corals have survived as a group over long evolutionary time periods is irrelevant to whether or not current changes in ocean pH will impact their ability to build coral reefs. Having a long evolutionary history, gives little information about whether or not marine calcifiers like corals were rare or not at any particular time. Extinction has never been the issue here. The issue is as follows: If corals become rarer (and/or calcify less) due to ocean warming and acidification (e.g. (Bruno and Selig 2007; De'ath et al. 2009) then their ability to build and maintain coral reefs will be diminished. This in turn will decrease the ability of coral reefs to provide ecological services and support to over 500 million people worldwide.
    4. “Carbon dioxide has been high in the past year coral reefs have continued to lay down calcium carbonate”.
    This is not supported by the bulk of scientific studies. Most of the evidence, reveals that marine calcifiers like corals did not form carbonate reef systems during periods of high CO2 in the past (Veron 2008 etc.). There are big gaps in the depositions of carbonate during these periods.
    ——————————————————————————————————————————————–
    Bruno, J. F. and Selig, E. R. 2007. Regional decline of coral cover in the indo-pacific: timing, extent, and subregional comparisons. PLoS ONE 2 (1):e711.
    De'ath, G., Lough, J. M., and Fabricius, K. E. 2009. Declining Coral Calcification on the Great Barrier Reef. Science 323 (5910):116-119.
    Veron, J. 2008 Mass extinctions and ocean acidification: biological constraints on geological dilemmas. Coral Reefs 27:459-472.

    It's almost like CO2 is a pollutant in some circumstances! LOL!

  6. k imma gonna post this now that i have an account maybe then it'll show up 😉

    SkepticalScience has a good post up now, by the author of one of the papers cited above: http://www.skepticalscience.com/Ocean-acid.html

    In particular:
    ————————————————————————————————————————————–
    3. “Organisms like corals have been around for hundreds of millions of years, over which time atmospheric carbon dioxide has varied greatly. Therefore, we don't need to be concerned about ocean acidification.”
    The fact that corals have survived as a group over long evolutionary time periods is irrelevant to whether or not current changes in ocean pH will impact their ability to build coral reefs. Having a long evolutionary history, gives little information about whether or not marine calcifiers like corals were rare or not at any particular time. Extinction has never been the issue here. The issue is as follows: If corals become rarer (and/or calcify less) due to ocean warming and acidification (e.g. (Bruno and Selig 2007; De'ath et al. 2009) then their ability to build and maintain coral reefs will be diminished. This in turn will decrease the ability of coral reefs to provide ecological services and support to over 500 million people worldwide.
    4. “Carbon dioxide has been high in the past year coral reefs have continued to lay down calcium carbonate”.
    This is not supported by the bulk of scientific studies. Most of the evidence, reveals that marine calcifiers like corals did not form carbonate reef systems during periods of high CO2 in the past (Veron 2008 etc.). There are big gaps in the depositions of carbonate during these periods.
    —————————————————————————————————————————————
    Bruno, J. F. and Selig, E. R. 2007. Regional decline of coral cover in the indo-pacific: timing, extent, and subregional comparisons. PLoS ONE 2 (1):e711.
    De'ath, G., Lough, J. M., and Fabricius, K. E. 2009. Declining Coral Calcification on the Great Barrier Reef. Science 323 (5910):116-119.
    Veron, J. 2008 Mass extinctions and ocean acidification: biological constraints on geological dilemmas. Coral Reefs 27:459-472.

    It's almost like CO2 is a pollutant in some circumstances! LOL!

  7. there's a paper out that documented a population pushed to its extreme by rapid environmental change. The population adapted… but….

    "Our results suggest that sufficient genetic variation exists in the ancestral marine stickleback population to permit the rapid evolution of a 2.58C shift in cold tolerance. However, we caution against interpreting this result as suggesting that natural populations can adapt to climate change without negative consequences. The strong selection required to shift a phenotypic trait so rapidly can result in large changes to population and ecological dynamics, which may in turn negatively affect population persistence [36 – 38]. "

    As summarized here[ http://blog.motheyes.com/2010/08/rapid-adaptation… ], even if a population can adapt to sudden changes, the evolutionarily rapid increase in selection pressure can lead to genetic bottlenecks, which can haunt a species for a while (look up cheetahs). The populations discussed collapsed after the study ended, when an unusually cold winter apparently pushed them beyond their adaptive ability. The paper notes that the temperature changes expected from AGW are at least as large as those in the experiment.

    Rowan D. H. Barrett, Antoine Paccard, Timothy M. Healy, Sara Bergek, Patricia M. Schulte, Dolph Schluter, and Sean M. Rogers
    Rapid evolution of cold tolerance in stickleback
    Proc R Soc B 2010 : rspb.2010.0923v1-rspb20100923. http://rspb.royalsocietypublishing.org/content/ea

    Granted fish != coral and temp != pH, but it illustrates the drastic effects that evolutionarily rapid environmental changes like AGW can have, even for populations which technically survive the change.

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