Ocean Acidifi-WHAT?!

By Sheril Kirshenbaum | September 8, 2010 10:37 am

As I continue to speak around the country, I frequently ask if those in the audience who have heard of ocean acidification will kindly raise their hands. Sometimes a few do. More often I get blank stares. I’ve been writing about this subject for as long as I’ve been blogging. Longer if you count Senate memos and grad school projects over much of the past decade. Acidification is a huge deal. It’s as serious as climate change, which–despite Mr. Morano’s sorry efforts at special interest propaganda–is indeed a very real threat to biodiversity. Humans included.

So time for another post on what ocean acidification is, how it affects our world, and why this matters. It needs to become prominent on the national radar and a priority in policy discussions. I intend to keep blogging about it until more hands go up in the room. With that, another edition of:

Ocean Acidification 101

Most of us are aware that we’ve been adding lots of CO2 to the atmosphere from the combustion of fossil fuels, land-use changes, and more. But carbon dioxide is also absorbed in oceans and taken up by terrestrial plants. Initially, the marine realm served to mitigate climate change, but over time, excess accumulated CO2 has disrupted a long-established system of environmental checks and balances.

You see, in oceans, all of that dissolved carbon dioxide interacts with carbonic acid, bicarbonate, and carbonate. This leads to a decrease in overall pH making the them less basic. Readers who maintain aquariums likely know that monitoring pH is important for the well-being of the critters inside. The same goes for oceans.

Over the last 250 years, surface pH has decreased by approximately 0.1, but this was a gradual process so marine organisms had the chance to adapt. However, since the upstart of the industrial revolution, pH has been decreasing more rapidly leaving little time for animals to adjust. As a result, we’re already observing deleterious effects on the survival and behavior of some species. Additionally, increased acidity leads to reduced calcification and enhanced dissolution, meaning that corals, coccolithophores, algae, pteropods and more may be in trouble.

While science cannot predict the full ecological consequences of acidification, be assured that the oceans–already under a great deal of pressure–are more vulnerable than ever.Ā  And it’s especially important to remember that the plants and animals immediately impacted are not isolated in a closed system. When one part of the biosphere shifts, trophic cascades lead to the disruption all sorts of interactions and this imbalance eventually trickles up to us.

The take home message: What we don’t know, don’t understand, and often ignore can hurt us, so we’d better start paying attention to ocean acidification. Please help spread the word.

Ocean acidification illustrated by David Fierstein (c) 2007 MBARIImage: Ocean acidification illustrated by David Fierstein (c) 2007 MBARI

Comments (22)

  1. Perfect timing! I just used the same image to illustrate a slide on ocean acidification for my class in 15 minutes. šŸ™‚

  2. I spent a bit of time studying acidification and I noticed the immense calcium carbonate deposits in sea beds around the world. Have you seen studies where these were incorporated into models?

    How does water of different temperatures and PH react with mineral deposits. Admittedly the only control set we have is “how things were”, but still by comparing we might learn.

    While Natural climate change is a given, I’m still on the fence regarding large scale man-made climate change (gaseous water is a MUCH better greenhouse gas than CO2). However, the evidence of man-made acidification is pretty solid.

    I end up asking though. Even with HUGE systems like our oceans, slow change doesn’t really account for millions of years worth of staying within a certain range, what are the natural negative feedbacks into what many are assuming is an entirely positive feedback loop of change?

  3. When the audience is asked to raise hands, “Sometimes a few do. More often I get blank stares.” This is the exact response when I ask people about biodiversity. Many have heard of it, but few know what it means. Maybe we need a new paradigm in the way we use terminology so that it’s more readily understood by non-scientists.

  4. Scott,
    I understand why you’re on the fence, but you do understand that H2O(g) has a restriction on its effects that CO2 does not, right? H2O’s concentration rapidly drops with rising altitude, and beyond the troposphere is pretty negligible. CO2 doesn’t have such a restriction, since it doesn’t condense or freeze out. It is because of feedbacks between CO2 raising the temp a small amount, and then the additional H2O(g) raising the temp a larger amount that CO2 causes most of its rise.

  5. vel

    “I noticed the immense calcium carbonate deposits in sea beds around the world. Have you seen studies where these were incorporated into models?” I’m guessing,if they haven’t been incorporated, it would be because they aren’t available for neutralization being in the sea bed as a deposit.

  6. Nullius in Verba

    “H2Oā€™s concentration rapidly drops with rising altitude, and beyond the troposphere is pretty negligible. CO2 doesnā€™t have such a restriction, since it doesnā€™t condense or freeze out.”

    True, but the pressure drops, which also confines CO2’s contribution to the troposphere. 90% of the CO2 is below 11 km, because 90% of the air is. CO2 and H2O operate over roughly the same altitude range. Your description of the water vapour feedback is correct, but is only one of many feedbacks, and the net effect is poorly understood.

    Another question to ask the room – what was the atmospheric CO2 level at the time molluscs and corals first evolved? See how many hands go up, now…

  7. Gaythia

    As chemist/geochemist, I’d rather see a more complete explanation presented than the phrasing: “all of that dissolved carbon dioxide interacts with carbonic acid, bicarbonate, and carbonate” as a description of the pertinent chemical equilibrium. But rather than compose something myself, I’d like to refer anyone interested to this reference, which has clear graphics as well as good introductory commentary on the chemical and biological interactions involved:
    BBC News: Acid Oceans

    Additionally, NOAA also has a lot of worthwhile publicly accessible links on it’s website:

    For those with more specific interests, the following website may be worth investigating:
    Ocean Carbon and Biogeochemistry:

    The following paper might be of interest to Scott Reimers @2 above, and others, regarding the complexities of the modeling involved. I do not believe that it is correct to characterize the issue as “what many are assuming an entirely positive feedback loop of change”:

    Both of the two links above give references to studies regarding the question raised by Nullius in Verba @6 regarding such factors as CO2 levels, pH as they relate to life forms and geologic history.

  8. David

    I think that they are making a mistake by jumping in immediately with the doom and gloom CAGW as the means to increase their standing.

    Citing their Guide to best practices. (http://www.epoca-project.eu/index.php/guide-to-best-practices-for-ocean-acidification-research-and-data-reporting.html)

    “Ocean acidiļ¬cation is an undisputed fact.”
    What a great opening line. Why research it at all if it is all decided already?

    “As this new and pressing ļ¬eld of marine research gains momentum,….”
    Don’t they realize that the geochemists have been studying the ocean chemistry for quite a few years? Reading through their contributers, I find the lack of these geochemists rather startling.

    “While our understanding of the possible consequences of ocean acidiļ¬cation is still rudimentary, both the scientific community and the society at large are increasingly concerned about the possible risks associated with ocean acidiļ¬cation for marine organisms and ecosystems.”

    But, we must jump on the bandwagon and make sweeping changes based on preliminary findings.

    Then we have the conflicting nonsense that they put out that detracts from the real importance of what they are studying. This is from the FAQs (http://www.epoca-project.eu/index.php/restricted-area/documents/cat_view/59-faq.html) .

    One one hand, we must act immediately:
    “It is within our technical and economic means to modify our energy and transportation systems and land-use practices to largely eliminate carbon dioxide emissions from our economies by mid-century.”

    But of course we have already passed the tipping point to disaster:
    “neutralizing all of the CO2 from human activity that is entering the oceans with this process alone would take hundreds of thousands of years. ”

    The really awful thing is that I think that there is a lot of good science going on in this area. Unfortunately, they are trying to leverage the CAGW furor to increase their visibility.

  9. Thanks for posting this. I was well aware of the decline in fish stocks in the ocean due to overfishing, but I wasn’t familiar with the fact that pH is changing and that this is part of the influence.

    What really frustrates me is when people focus on AGW as being the sole environmental problem that this world is facing. No, it is so much more than that. Deforestation, overfishing, air pollution, overfarming, waste disposal etc are just as important issues and have the potential to cause just as much damage as climate change. I have witnessed a number of people claiming that AGW is false and then go off assuming that therefore we’ve got nothing to worry about regarding any environmental problems. Nothing could be further from the truth.

  10. You see, in oceans, all of that dissolved carbon dioxide interacts with carbonic acid, bicarbonate, and carbonate

    Hi Sheril, the CO2 does not interact with carbonic acid, it reacts with water to form carbonic acid, carbonates and bicarbonates. The resulting low pH medium then dissolves calcium carbonate.

  11. @Hudders,
    You are correct that the world faces many environmental problems, not just the climate crisis. That said, I’d point out that many of the examples you give are either drivers of that crisis, or are exacerbated by it. The real fundamental makes-my-blood boil issue is the lack of understanding of the interconnectedness of the Earth’s ecosystem, and especially humans place in that ecosystem. We do not stand apart from what happens around us.

  12. GM

    9. David Says:
    September 8th, 2010 at 11:38 pm
    ā€œOcean acidiļ¬cation is an undisputed fact.ā€
    What a great opening line. Why research it at all if it is all decided already?

    After spending years trying to discredit global temperature records (and pulling off some amazing feats of shameless lying with a straight face in the process), what’s next for the denialists – we’re going to try to show that pH meters are completely useless or what?

  13. Gaythia

    @Wavefunction, quibbling between chemists: Of course, I agree with you that the correct word is “react”. But I’d be interested in your ideas on conveying the concepts of chemical reaction equilibria to non chemists, and especially non scientists. I think that the problem with the word react, is that to those not initiated into chemical vocabulary, reactions sound as if they ought to be complete. This gives rise to the questions of readers and those in comments above who may be wondering why carbonate rocks at the ocean bottom wouldn’t just neutralize all of the excess acid.

    Biologists get into similar problems with the use of the word “theory” as in Theory of Evolution. When are we better off using words that fit with preconceptions of the public, and when do we need to teach them more of the details of what we really mean?

    See my #7 above.

  14. jld

    Yeah, yeah, yeah, ocean acidification, climate change, resources depletion, population explosion, the Sixth Extinction, etc, etc…
    How many things needs to become prominent on the national radar and a priority in policy discussions?
    What do you expect?
    Though you might notice a common factor to all these: speed of change (unmanageable…)

  15. Eric the Leaf

    I think I get your continental drift. As Catton has stated: the future will be “as unavoidable as it will be unwelcome.”

    –William R. Catton Jr., “Overshoot: The Ecological Basis of Revolutionary Change,” 1980, page vii.

  16. David


    No, I am not disputing pH, I am just amazed at the attitude of using that for the opening line of a document addressed *to researchers* in their guide for research and data reporting. If you take the time to read their documentation, the whole “don’t you dare say anything but the party line” attitude is pretty high handed.

  17. I’d heard of ocean acidification and became even more interested in it when articles and blogs came out about its effects on crustaceans like this one over at 80beats:


    As an artist, I decided to do a conceptual painting on subject here(Blue Crab):


    It certainly garners interesting conversations when I talk with people about the subject that inspired the piece.

  18. Recycle

    There are some great suggestions in this post! I also enjoy watching the tips on GreenopolisTV’s YouTube channel at http://www.youtube.com/greenopolistv because they always give me great ideas of things to do to help the environment too.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

About Sheril Kirshenbaum

Sheril Kirshenbaum is a research scientist with the Webber Energy Group at the University of Texas at Austin's Center for International Energy and Environmental Policy where she works on projects to enhance public understanding of energy issues as they relate to food, oceans, and culture. She is involved in conservation initiatives across levels of government, working to improve communication between scientists, policymakers, and the public. Sheril is the author of The Science of Kissing, which explores one of humanity's fondest pastimes. She also co-authored Unscientific America: How Scientific Illiteracy Threatens Our Future with Chris Mooney, chosen by Library Journal as one of the Best Sci-Tech Books of 2009 and named by President Obama's science advisor John Holdren as his top recommended read. Sheril contributes to popular publications including Newsweek, The Washington Post, Discover Magazine, and The Nation, frequently covering topics that bridge science and society from climate change to genetically modified foods. Her writing is featured in the anthology The Best American Science Writing 2010. In 2006 Sheril served as a legislative Knauss science fellow on Capitol Hill with Senator Bill Nelson (D-FL) where she was involved in energy, climate, and ocean policy. She also has experience working on pop radio and her work has been published in Science, Fisheries Bulletin, Oecologia, and Issues in Science and Technology. In 2007, she helped to found Science Debate; an initiative encouraging candidates to debate science research and innovation issues on the campaign trail. Previously, Sheril was a research associate at Duke University's Nicholas School of the Environment and has served as a Fellow with the Center for Biodiversity and Conservation at the American Museum of Natural History and as a Howard Hughes Research Fellow. She has contributed reports to The Nature Conservancy and provided assistance on international protected area projects. Sheril serves as a science advisor to NPR's Science Friday and its nonprofit partner, Science Friday Initiative. She also serves on the program committee for the annual meeting of the American Association for the Advancement of Science (AAAS). She speaks regularly around the country to audiences at universities, federal agencies, and museums and has been a guest on such programs as The Today Show and The Daily Rundown on MSNBC. Sheril is a graduate of Tufts University and holds two masters of science degrees in marine biology and marine policy from the University of Maine. She co-hosts The Intersection on Discover blogs with Chris Mooney and has contributed to DeSmogBlog, Talking Science, Wired Science and Seed. She was born in Suffern, New York and is also a musician. Sheril lives in Austin, Texas with her husband David Lowry.Interested in booking Sheril Kirshenbaum to speak at your next event? Contact Hachette Speakers Bureau 866.376.6591 info@hachettespeakersbureau.comFor more information, visit her website or email Sheril at srkirshenbaum@yahoo.com.


See More

Collapse bottom bar