Please note the title says acidifying oceans not acid oceans as the oceans are still alkaline, not acid. They are acidifying in the same sense that boiling water cools but is still hot. Since pre-industrial times the oceans have acidified by about 30%, which is not a benign process for certain calcifiers that live in the ocean and with uncertain impact on the rest.
The problem is that one of those calcifiers is zooplankton, which are at the bottom of the food chain going all the way up to whales. The bad news the other day was that these little critters in the sub-Antarctic area of the Southern Ocean, just north of Antarctica, are losing the ability to make shells perhaps 100 years ahead of schedule.
The only good news out of this was that the problem is being studied, because our knowledge in this area was almost non-existent 10 years ago.
Since I picked it up in a bookshop last year and read it I have been meaning to post about Alanna Mitchell’s book Seasick: the hidden ecological crisis of the global ocean. Mitchell, a Canadian journalist, doesn’t have the density of information that you get at Wikipedia or at RealClimate on this or any related subject, but she tells you what you need to know in an engaging and accessible personal narrative.
She must have had a huge budget to research the book as she travelled the world, not only meeting the frontline scientists but joining them at their work stations and in field trips in countries around the world. So you get to know the scientists, how they go about their work and how they feel about the issues they are exploring, and about the evident destruction being wrought upon this still largely hidden world.
Mitchell relates how Joan Kleypas at a meeting in Boston in 1998 was sharing information with colleagues about the effect on CO2 on the chemical composition of oceans, doing some back of the envelope calculations on a subject that hadn’t rated a mention in university courses, when they “realised they were looking at a marine Armageddon”.
Kleypas ran into the bathroom outside the committee room and threw up.
She realised that some calcifiers would go extinct, and as a consequence some other life forms would vanish. Furthermore, as the calcifiers die they take carbon down to the sea floor with them. This service would cease. Finally, plankton produce about half the oxygen in the atmosphere.
Kleypas and others turned the back of the envelope calculations into a scientific paper published in 1999, cited at the end of the RealClimate post, but found other scientists reluctant to accept the true vulnerability of the oceans. Back in 1999 the article
received a lot of press coverage and drew a chorus of outrage from fellow scientists who questioned everything about the premise, from the chemistry to the calculations to the assumptions.
They called for more investigations and more analysis, including examination of other eras of earth’s history when ocean chemistry changed rapidly. All subsequent research has backed up Kleypas, Langdon and the others.
Caldeira and Wickert found in 2003, for example, that
unabated CO2 emissions over the coming centuries may produce changes in ocean pH that are greater than any experienced in the past 300 Myr, with the possible exception of those rare, catastrophic events in Earth’s history.
Ocean pH levels are normally buffered by ocean chemistry so that they stay in equilibrium, through a mechanism called CaCO3 compensation. This mechanism works on time scales of thousands of years. The rate of CO2 increase is currently too fast for this mechanism to cope, producing an acid spike more intense than has been seen for at least 800,000 years, probably much longer.
The current research suggests that the problem is not academic, worked over in models, it’s real.
For Mitchell the bottom line is that we just don’t know to what degree humans are symbionts with all the other creatures we are endangering. Life forms in the sea could get along just fine if all the life on land was wiped out. Whether we can live with dead or even significantly depleted seas is a question.
Ocean acidification is Chapter 3 of Mitchell’s book. Other chapters deal with topics such as dead zones, species loss and over-fishing, and coral reefs. Chapter 4 deals in more detail with what is going on with plankton. As I get time and as the spirit moves me I’ll post on these chapters. There is a a review at Treehugger.
Mitchell says:
The two media of life on the planet – air and water – exchange gases across the vast surface of the ocean exactly where the water molecules meet those of the air. It’s a continuous, two-way process that is key to the earth’s ability to support life as we know it.
Not the key, just key. But for Mitchell in unlocking that key and unravelling the mysteries of the oceans we will find out not where we’ve come from but where we are going.
Update: steve from brisbane @ 3 makes the good point that skeptics/denialists/delusionists have no valid response to the issue of ocean acidification. They can’t deny the existence of extra CO2 in the atmosphere and the rest follows from there.
We’ve known about the risk to the oceans on many fronts since at least the sixties, and have given that knowledge scant regard. That period of time, 40 years may seem like an eternity to some people, but in terms of nature it is just a blip. And the time that we have left to make any meaningful impact is half a blip.
The only solution from an Australian government perspective, is to create an environmental authority along the Reserve Bank lines, an authority that is independent of government and has the mandate to change key factors in reaction to the environmental need, as outlined in its constitution, without challenge. The obvious factor would be the price of carbon, but there would be other mechanisms that will be pivotal in minimising environmental damage.
This task is beyond the abilities of politicians.
bloody hell, Brian! Makes sea-level rise look like a drop in the ocean!
I have been arguing for a few years now that, regardless of uncertainties with the exact range of temperature increase from AGW, ocean acidification and its potential for disastrous ecological changes is actually a more certain reason to dramatically reduce CO2 production. (Major extinction events in the oceans and on the land may have had significant contribution from the oceans, and there is no doubt present ocean pH will continue to drop, as the chemistry is pretty simple.) Yet it is a field that only intermittently attracts much in the way of media attention.
I have also argued that the likes of Ian Plimer do not address this in detail; I have heard him recently say that it is well understood that ocean chemistry neutralises the increased acidity (without mentioning, of course, the thousands of years it takes to do so.) Essentially, I don’t think the skeptics have any detailed way of responding to it, apart from generic statements of faith along the lines of “everything will be all right, you ideological alarmists.” (And then they start a silly argument over whether “acidification” is the correct term to use.)
It is true to say, however, that there has been some uncertainty (and contradictory experimental results) regarding the response of certain creatures to lower pH. It really does need more urgent research, but it still seems clear enough from present work that there are enough creatures who clearly don’t do well (pteropods, certain corals, etc.) to take it very seriously indeed.
If people haven’t read it, the 2005 Royal Society paper sets out the science in detail, and you could much worse than search my blog (forgive the self promotion, but I’ve been trying to get people to think about this for a long time) for “ocean acidification” to read lots of posts on the topic pointing to various research over the last few years.
It’s bloody disturbing Brian, and equally disturbing that govts et al seem to be paying even less attention to this. Shit, anyone with a fish tank will know what happens when you increase the carbon input into a tank – fabulous plant growth and precipitous ph and algal drop.
BilB, it’s a problem of the global commons and unfortunately the problems of the sea are not limited to pH levels. The chapter on overfishing was horrifying, and I might do that one next.
As a problem of the global commons, I’m not sure how to tackle it institutionally, so your suggestions are welcome. Whatever we do governments will have to see the need and set it up.
The Path Lab, like sea level rise, the time scales are long, so turning things around won’t be easy. Since I read Mitchell’s book I’ve been worrying about the implications for ocean acidification of leaving significant concentrations of CO2 in the atmosphere, at 450ppm for example, for any length of time. Also the notion of taking it right back to 280ppm has seemed more compelling.
It seems that we simply don’t know anywhere near enough. As steve confirms, there needs to be more research and more media attention. Thanks for that summary, steve, and pointers to additional information. The chemistry may be simple to you, but it stretches my school level knowledge past breaking point. I was worried my summary might contain a huge clanger demonstrating my ignorance. There is a need for information accessible to lay persons, which Mitchell’s book certainly is.
Can Anthropogenic Ocean Acidification (AOA) be plausibly denied? Seems unlikely, but the delusionists are, well, delusional. Surely they can only argue that the effects aren’t that serious, not that AOA isn’t happening.
I wouldn’t think so.
Anyone that’s taken high-school science remembers acids.
Ken Caldeira at RealClimate wonders whether we would be further along in public perception if the terminology for CO2 in Arrhenius’s original 1896 paper on CO2-induced greenhouse warming had been maintained – “On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground.”
Brian @ 5 – you could also add this to your list of problems with the oceanic commons
Um, I’m sorry to say that I have double checked and found the “Search Blog” function on my blog is far from adequate; if anything, it seems to be getting worse, even though I have now added a label to my ocean acidification posts. You have to use Google Blog search and specify the URL. Maybe that’s why people move to Wordpress?
The disclaimer about the semantics of the term acidification just highlights the sort of thought processes of bloggers on sites like WUWT. The idea that the while the pH content of the oceans are moving towards the acidic spectum, but that it will never actually cross over the threashold means that you cannot use the term acidification just stinks of political correctness or an attempt to try and rebrand the process in a similar way to how the Republicans attempted to push the term climate change instead of global warming earlier this decade.
Carbonsink – AOA is a real tricky point for denialists. Isotope ratio measurements show a fairly strong link to fossil fuel created CO2 and no-one ahs come up with an alternative explanation. Various people have tried to explain it “away” by describing oil-field outgassing and then been promptly shot down by (ironically) the exploration well data. Not to mention the solid cap most of these fields have. SOme “breathing” occurs here and there but it is very localised (NOT global).
it’s my customers and instrumentation experience I’m using here.
My geology is pretty weak so maybe someone else has the raw data, but at this stage the acidity is definitely surface-based with strong atmospheric-capture charactoristics. Not just shell weakness but also just about every other uptake path in animals have shown direct/indirect effects from decreasing pH.
Just another physicist talking outside his field
We just need to mine out all the limestone we can and dump it in the oceans… fixed! Hey, maybe that would also be a good way to sequester more CO2.
Ocean acidification is a killer of several good geo-engineering proposals. We can’t just pump out CO2 and make amends, we have to stop pumping out the damned stuff in the first place.
An interesting commercial side effect if the ocean actually becomes acidic is that it will corrode steel hulled vessels and infrastructure such as bridges and piers, rather more rapidly than at present. (Aluminium vessels are less at risk.)
The effect may be insignificant compared with damage to sea life from acidic water, but the risk may attract attention from businesses that otherwise are not too concerned about climate change.
Good point. Big mirrors in space won’t fix ocean acidification. Robert?
Carbonsink, I agree totally that sunshades can’t fix ocean acidification, which is as almost as serious as climate change.
Sunshades of whatever form can only be a very temporary fix while CO2 levels are brought back down, whether by natural processes or by deliberate actions.
MikeM, my chemistry is crap, but the oceans are still well and truly on the alkaline side of the balance. Would the corrosion thing really be a factor?
You stupid old man. You cannot tell me that you’ve fallen for this outrageous crap as well?
I’ve added an update to the post to emphasise the point made by steve from brisbane @ 3 that skeptics/denialists/delusionists have no valid response to the issue of ocean acidification.
I think the comment @ 19 must have been placed in moderation by one of my co-bloggers. I’ve approved it just to illustrate that they are still out there in all their glory!
I suspect there are quite a lot of things you cannot tell Totalscienceman.
Do you think he’s related to DuffMan?