SHELL GAME: Foraminifera, like Globigerina bulloides pictured here, are having a harder time building big shells in a more caustic Southern Ocean.
Image: COURTESY OF ANDREW MOY
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The shells of tiny ocean animals known as foraminifera—specifically Globigerina bulloides—are shrinking as a result of the slowly acidifying waters of the Southern Ocean near Antarctica. The reason behind the rising acidity: Higher carbon dioxide (CO2) levels in the atmosphere, making these shells more proof that climate change is making life tougher for the seas' shell-builders.
Marine scientist Andrew Moy at the Antarctic Climate & Ecosystems Cooperative Research Center (ACE) in Hobart, Tasmania, and his Australian colleagues report in Nature Geoscience this week that they made this finding after comparing G. bulloides shells in ocean cores collected along the South Tasman Rise in 1995 with samples from traps collected between 1997 and 2004. The cores provide records that stretch back 50,000 years.
"We knew there were changes in carbonate chemistry of the surface ocean associated with the large-scale glacial-interglacial cycles in CO2 [levels], and that these past changes were of similar magnitude to the anthropogenic changes we are seeing now," says study co-author William Howard, a marine geologist at ACE. "The Southern [Ocean] works well [to study this issue] as it is a region where anthropogenic CO2 uptake, and thus acidification, has progressed more than in other regions. Other variables, such as temperature, have changed, but not as much."
The researchers found that modern G. bulloides could not build shells as large as the ones their ancestors formed as recently as century ago. In fact, modern shells were 35 percent smaller than in the relatively recent past—an average of 17.4 micrograms compared with 26.8 micrograms before industrialization. (One microgram is one millionth of a gram; there are 28.3 grams in an ounce.)
"We don't yet know what impact this will have on the organisms' health or survival," Howard says, but one thing seems clear: the tiny animals won't be storing as much CO2 in their shells in the form of carbonate. "If the shell-making is reduced, the storage of carbon in the ocean might be, as well."
That's bad news for the climate, because the ocean is responsible for absorbing at least one quarter of the CO2 that humans load into the air through fossil fuel burning and other activities—and it is the action of foraminifera and other tiny shell-building animals, along with plants like algae that lock it away safely for millennia.
It will be harder to get such a clear sign in a shell from other ocean regions—as variables like temperature and the amount of minerals available can significantly change the chemistry of a given ocean region. As Howard noted, the Southern Ocean has absorbed lots of manmade CO2 while temperatures and nutrients have not changed as much, making it more ideal for studying ocean acidification than other areas. Scientists examining foraminifera in the Arabian Sea, however, have found similar results, and Howard speculates the situation may be similar in the North Atlantic region, because it also absorbs a significant chunk of manmade CO2.
Howard says that CO2 emissions must be cut or captured and stored permanently in some fashion to halt this gradual acidification of the world's oceans. In the meantime, he adds, it's likely that many of the other shell-building oceanic animals are suffering similar fates as G. bulloides.
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18 Comments
Add CommentReports call the alarm of ocean acidification, adding acid flames to the raging fires of fossil CO2. Whats missing is mention of the best, only, means to fight ocean acidification. The real problem is not tomorrows CO2, but yesterdays CO2. We must turn our attention to the 1000+ gigatonne carbon bomb, two centuries of CO2, still mostly in the air as it takes centuries for airborne CO2 to equilibrate with the rest of the planet.
Reply | Report Abuse | Link to thisOnly 500 gigatonnes of yesterdays CO2 has reached the oceans where Revelles Rule tells us 80% of CO2 ends up. The first carbon bomb will be exploding in the ocean for more than a century even if we stop the emission of new CO2 today. No amount alternative energies, recycling, bicycling, or clean coal will tend to the first carbon bomb. Sure lets reduce the size of the second bomb but first things first. Here's how.
ONLY ocean replenishment and restoration can enlist, as allies, the most powerful force of nature - the ocean plants, the bloomin plankton. But high and rising CO2 in the air is not only responsible for ocean acidification worse it has fed green plants on land making them greener, bushier, and living longer making them "good ground cover." Ground cover improvements have reduced the amount of dust blowing in the winds by 1/3 in just a few decades. For the oceans dust in the wind brings vital mineral micro-nutrients to the oceans, that terrestrial Yin is just as important as rain, the Yang, blowing from sea to land nurturing plant life. Since earth and ocean satellites went aloft 30 years ago we've measured decimation of ocean plants, 10% are gone from the Southern Ocean, 17% from the N. Atlantic, 26% from the N. Pacific, and 50% from the tropical seas. Just yesterday, a few decades past, ocean pastures grew more verdant consuming 4-5 billion tonnes more CO2 each year than today.
Today, as stewards of our blue planet, we must replenish ocean micro-nutrients to restore the ocean pastures. If we bring the ocean plankton blooms back to levels seen only 30 years ago those plants will annually convert billions of tonnes of CO2 into ocean life instead of acid ocean death. In the bargain the restored oceans will feed everything from tiny krill to the great whales and everything and everybody in between - fish, seabirds, penguins, seals and us.
Replenish and restore the oceans without delay. Read more at www.planktos-science.com
As sea plants require extra nutrients to feed on if they are to grow bigger, so do land plants. Admittedly extra CO2 is there, but trees will only grow bigger if they have extra nitrogen, potassium and phosphorous available too. This is not the case, so exit yet another potential carbon sink...
Reply | Report Abuse | Link to thisThese people definitely need to review their freshman chemistry. It is inconceivable that tiny fluctuations in trace amounts of CO2 can realistically influence the pH of the oceans and affect the shells of ancient foraminifera. CO2 has comprised about 0.0003 parts of the atmosphere since ancient times (that's 300ppm) and has not fluctuated more then 0.00006 parts (60ppm). Human induced global warming by CO2 emissions is absurd. A. Lipkin, Ph.D., Professor of Chemistry Emeritus.
Reply | Report Abuse | Link to thisif you think the ocean is acid, what are you doing ? if you were a scientist, you would do an experiment; not scoff at those who do...one experiment is to collect and grow native food chain plankton, not from a test tube. then release them as i have done, in ocean dead zones, and see how quickly the zone is not dead.... http://www.google.com/search?hl=en&q=++++++++++hi%2C+tuesday+sept+5%2C2006%2C+i+released+lincoln+city+winter+marine+phytoplankton+&btnG=Google+Search
Reply | Report Abuse | Link to thisNeoguru,
Reply | Report Abuse | Link to thisGrats on the PhD, but apparently you aren't too up on the recent literature. There is an overwhelming body of literature on this very subject. I advise you to take a look. This is not a process that "will" happen, but instead "is" and "already" happening.
Do the experiment for yourself, as I have done this many times already running biological experiments testing this very concept. Take an enclosed aquarium with saltwater. Diffuse CO2 into the water, test the pH. You can then enclose the aquarium (air tight) and let the resultant CO2 and air above the aquarium equilibrate with each other. Measure the air CO2 concentration. I think you'll find this isn't as "inconceivable" as you though.
Oh, and being a chemistry professor doesn't lend any weight to your opinions on climate science. Because apparently you don't know the fundamental physics behind climate science.
Start reading some recent peer reviewed literature again on the subject.
No, YOU do the research Shoreliner! Use concentrations of CO2 that are in the atmosphere, not thousands of times normal. The air has only 0.03% CO2 and has only increased 0.006% over the last 200 years. See what happens when you use realistic concentrations and not thousands of times normal. At realistic levels I assure you that you'll notice no substantial changes in the pH of your fish tanks. Alan Lipkin
Reply | Report Abuse | Link to thisLOL, I have actually. I find it hard to believe that you alone have found the loophole in this process. You refute the hundreds of scientists who have published on ocean acidification, and further refute some of the principal findings of the IPCC (which have chemical oceanographers on the list). Point me to some of your peer reviewed articles where you show that the pH doesn't rise when you double the atmospheric CO2 concentration. And we didn't use 1000x normals levels of CO2. It works out to realistic levels on our current emissions path (ie 750ppm-1000ppm)
Reply | Report Abuse | Link to thisRegarding increases in CO2 concentration, I don't have to tell you, having a PhD in chemistry, that green house gases don't have to be in high concentrations to make a huge difference. Methane is one of the strongest greenhouse gases, yet its concentration is 1.745 ppm or (0.0001745% of the earth's atmosphere). Try doubling that GHG and see how the world reacts. You can either cling to your ideals, or point to legitimate science supporting your ideas. The vast majority of the literature points to ocean acidification already occurring and will increase along with the atmospheric CO2 concentrations.
Here's the CO2 data from the last 50 or so years.
http://www.esrl.noaa.gov/gmd/ccgg/trends/co2_data_mlo.html
In the 60's we were slightly below 320ppm, and are now at about 385ppm. You do the math on the increase in concentration over that period of time. I'll give you a hint, its over .006%
Math U say? Here ya go: 320ppm to 386ppm = difference of 66ppm - that's an 0.0066% increase in the concentration of CO2, no? Your 1000ppm is an increase of over 300%. That's 50,000 times the increase experienced over the last 50 years! Very realistic, huh? Here's a little unrealistic calculation that I did: If you were to heat ALL the atmospheric CO2 to 1000deg, the resulting rise in the world temperature would be 0.35deg. Of course this isn't possible, but it demonstrates the tiny effect that even radical changes in trace gases can have on world climate. The concentration is just too low for any realistic effect. Wanna check MY math? NeoGuru@aol.com
Reply | Report Abuse | Link to thisFirst off, on your math,
Reply | Report Abuse | Link to thisHere's a quote from the IPCC,
"Carbon dioxide (CO2) is the most important anthropogenic GHG.
Its annual emissions have grown between 1970 and 2004 by about
80%, from 21 to 38 gigatonnes (Gt), and represented 77% of total
anthropogenic GHG emissions in 2004 (Figure 2.1). The rate of
growth of CO2-eq emissions was much higher during the recent
10-year period of 1995-2004 (0.92 GtCO2-eq per year) than during
the previous period of 1970-1994 (0.43 GtCO2-eq per year). {WGIII
1.3, TS.1, SPM}"
Yes, they're referring to CO2 output in weight, but I've included this to point out this isn't some trivially small amount of gas here.
All you've done is convert the difference in ppm to a decimal percentage of atmospheric volume. This does not tell us the percentage "increase" in CO2. Now if you calculate what the percentage increase 386-320= 66...66/320= .206 = 20.6% increase in CO2 since the 1960's. You can get the same value if you convert all the ppm to decimals before and divide which you forgot.
Because you don't want to read the relative science yourself, I've quoted the IPCC here for you. And forgive me for believing the scientists who publish their work on the subject.
"3.3.4 Ocean acidification
The uptake of anthropogenic carbon since 1750 has led to the
ocean becoming more acidic with an average decrease in pH of 0.1
units. Increasing atmospheric CO2 concentrations lead to further
acidification. Projections based on SRES scenarios give a reduction
in average global surface ocean pH of between 0.14 and 0.35
units over the 21st century. While the effects of observed ocean acidification on the marine biosphere are as yet undocumented, the progressive acidification of oceans is expected to have negative impacts
on marine shell-forming organisms (e.g. corals) and their dependent
species. {WGI SPM; WGII SPM}"
You wrote "The concentration is just too low for any realistic effect." By this notion, no greenhouse gas would have any effect here on earth. These molecules ARE low in concentration, though that doesn't negate their radiative warming effects.
It's not that you don't believe in Anthropogenic caused global warming. You don't believe in the GHG concept altogether. Otherwise you would have realized all GHG's are in small concentrations, though they are still responsible for this planets mild temperatures. As I said, methane is in very small concentrations even relative to CO2, though its still one of our strongest greenhouse gases.
I never argued that humans have increased CO2 levels and it's common knowledge that we've been in a warming trend for the last 12,000 years. I'm saying the two are unrelated. CO2 is 25% more efficient at absorbing heat then air. Methane is over twice as efficient. (Go 'head and look 'em up.) But the trace amounts in the atmosphere, even if more efficient heaters, simply aren't enough to warm it to the degree we're led to believe. It's sensationalized and scientifically inaccurate. It's impossible. And yes, it IS a trivial amount of CO2 we're dealing with. The number is only impressive when omitting the totals involved. Again - these are TRACE greenhouse gases. Your "20% increase" only amounts to a total change in atmospheric CO2 of 0.006% over the last 50 years and you're fooling with 50,000 times those concentrations. Sooo.... no more math questions?? Now, about your chemistry. Do the calculations and determine how much CO2 would be required to lower the pH of the oceans 0.14 to 0.35. YOUR turn for the big surprise - there ain't that much CO2 in the atmosphere. Good luck with your research.
Reply | Report Abuse | Link to thisbtw Shoreliner - Your's was the only intellegent arguement I've gotten back and it's very much appreciated. I've always felt that if you cannot defend a position then it is indefensible. Thank you for your interest. A. Lipkin
Reply | Report Abuse | Link to thisI definitely don't mind a spirited debate,
Reply | Report Abuse | Link to thisReferring to the concentrations we're using, we are using CO2 concentrations that are predicted for the end of this century given business as usual. The current increase we were calculating lacks several positive environmental feedbacks that increase warming (ie lack of arctic sea ice and permafrost/methane).
There isn't that much CO2 in the atmosphere, YET, but there will be with the continued burning of fossil fuels. I would absolutely love this to be some sort of sensationalized hoax. That way the organisms I have seen decline under low pH conditions, would better survive. Unfortunately the science doesn't point that way.
One real world example I like to bring up is coral bleaching. Being a marine biologist I feel this is something I know and can explain better. Coral bleaching is the process by which corals' algal symbionts, zooxanthellae, leave the host coral and in turn the coral has no means to effectively survive long term without the reuptake of zooxanthellae. There has been some debate over whether this is an adaptive process or not, but the current literature does not point to this.
Corals were not observed to bleach since they were described (many of the first in the 1800's) until the mid 1980's. Now we've had several ocean basin wide bleaching events in the Caribbean as well as areas in the indo-pacific. Bleaching is caused by several factors, but the most severe is warm ocean waters (above 30 C) for sustained periods of time. The largest bleaching event was in 1998 with the severe El Nino event. Although, since this time there have been several smaller bleaching events even during the cooler La nina years.
This story is purely anecdotal although there is a breadth of literature linking climate change to coral bleaching. I point it out because its a real world example of an awfully big coincidence if you don't believe the science on climate change. The only issue I have is that "IF" on some crazy turn of events, the leading (and vast majority) climate scientists in the world are right, the dire outcomes should be enough for those who don't believe the scientists (and for many don't understand it--not you, just public in general) to reconsider their previous thoughts on climate change.
Just for fun read this quick articles I found
http://thethirdwave.wordpress.com/climate-change-for-dummies/
and this ones good as well. Not for its negative connotation towards 'deniers' but because it has a lot of commonly misconceived concepts easy to find.
As you've seen, I too love a good scientific debate. Please note that I fully understand that global warming is occuring. We're in the midst of a roughly 15000 year Milankovitch Warming Cycle and world climate should continue to warm for another few thousand years, barring any big impacts or volcanic eruptions. And the CO2 levels are indeed rising. But just because they're both occurring does not mean there's a causitive relationship. It'd be wonderful to see an oceanic biologist conclude what I've found to be obvious - that tiny amounts of even potent greenhouse gases cannot realistically affect overall climate conditions to the extent we're led to believe. I'd love to stay in personal contact via emai. Perhaps you'd like the free services of a hot, critical organic chemist.
Reply | Report Abuse | Link to thisAlan Lipkin, NeoGuru@aol.com.
Just wondering if you've read anything by Caldeira and Wickett. They have some good papers to read on Ocean acidification projections. Here's one,
Reply | Report Abuse | Link to thishttp://www.ipsl.jussieu.fr/~jomce/acidification/paper/Caldeira_Wickett_2005_JGR.pdf
I'm curious as to your thoughts as they predict .3-.5 pH unit reductions by 2100.
Just wanted to point out that recently for work, I've had to delve into the literature related to this very subject. Specifically with coccolithophorids which are another calcifying plankton. If anyone wants I can link some of the relevant current literature on the subject.
Reply | Report Abuse | Link to thisAnd lastly, I think my explanation earlier regarding how we bring the pH down in aquaria is performed. I failed to say that the CO2 we diffuse (bubble) into the aquaria is actually at the specified ppm. So if we use 1000ppm for instance (estimated by the end of the century), it'll work out to around 7.9 ish (+or- somewhere around .005 units). I'm not sure what loopholes you can find in this method. If so, I'd be very interested in hearing them. The majority of all studies that touch on the effects of ocean acidification use similar methods.
So CO2 concentrations are not enough to affect temperature? How, then, do you explain the fact that calculating from the Earth's radiation balance, that we are not a planet with frozen oceans?
Reply | Report Abuse | Link to thisCan anyone direct me to any actual observable ocean rise on any American shoreline? A vast number of old photographs of Manhattan could be compared to present photos. This is the only kind of science I will trust. Actual real life observation.
Reply | Report Abuse | Link to thisCan anyone direct me to any old photos of American shorelines, such as in Manhattan, that show any change in sea levels? All the seas join together, so sea rise anywhere would be equal. Land mass changes should be taken into consideration though.
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