CORE RECORDS: Ancient ocean sediment rock cores reveal how microscopic sea life fared as waters acidified thanks to rising carbon dioxide levels in the atmosphere.
Image: Courtesy of Helmut Weissert
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Single-cell life-forms thrive throughout the world's oceans—and have for hundreds of millions of years. Tiny varieties known as calcareous nanoplankton build exuberant, microscopic shells—resembling wagon wheels, fishlike scales, even overlapping oval shields decorated with craggy explosions at their centers—known as "coccoliths". The ability to form these shells rests on the amount of calcium carbonate (CaCO3) dissolved in the seawater—and that amount depends on the concentrations of atmospheric carbon dioxide (CO2).
CO2 is the ubiquitous greenhouse gas emitted by human activity, particularly fossil-fuel and forest burning. As levels rise in the atmosphere (currently at 390 parts per million and counting), the ocean's surface waters absorb more of the molecule. This water–CO2 mixture forms carbonic acid, which slightly lowers the ocean's overall pH (the lower the pH, the more acidic). More acidic ocean water means less calcium carbonate—and less material for shell-building plants and animals of all sizes, including the nannoplankton that constitute the base of the food chain.
Of course the present era is hardly the first time the planet has seen higher levels of CO2. In fact, roughly 121 million years ago—during an age known as the early Aptian—global CO2 levels were likely higher than 800 ppm (and possibly as high as 2,000 ppm) thanks to cataclysmic volcanic eruptions. Now new research published in Science July 23 shows how ancestors of today's nannoplankton fared in those acidic oceans of long ago.
It was a time of "severe global warming," paleobiologist Elisabetta Erba of the University of Milan and her colleagues wrote, after studying the carbon isotopes embedded in deep seabed cores drilled in the Pacific Ocean and locations in the ancient Tethys Ocean, which existed during the Mesozoic era. The records reveal that acidification proved a big problem for nannoplankton. "During the Aptian episode, marine calcifiers experienced a major crisis due to increasing CO2-induced acidification," Erba says.
But that crisis was not a major extinction event. The nannoplankton responded by doing less shell-forming—the heaviest shell-formers, known as nannoconids, largely disappeared from the fossil record (although they did not go extinct, the same species reappear after acidification dwindles)—and by diversifying into new, smaller species. In some cases species even increased in abundance but shrank in size—by as much as 60 percent. "Malformation is also ascertained for some [widespread] species," Erba notes.
It took at least 25,000 years for the new acidity levels reached in the surface waters to transfer to deeper waters, according to the research—and the ocean took 75,000 years to reach its peak acidity for that episode, as well as at least 160,000 years to recover. The length of this episode derives "most probably because several CO2 pulses [volcanic eruptions] contributed to ocean acidification," Erba says. Further, she plans to examine other high CO2 events in the geologic record to see "if the same causes—excess CO2, global warming, ocean acidification—trigger similar effects on marine calcifiers at different times."
But the 25,000-year time lag between acidification of the surface waters and deeper waters is mysterious, points out geoscientist Timothy Bralower of The Pennsylvania State University, who was not involved in this study. "In the modern ocean, a similar input of carbon would involve a lag on the order of centuries," he notes. "So something is very different." And the nannoconids begin to disappear even before the fossil record indicates lighter volcanic carbon isotopes—in other words, presumably before the actual acidification. Nevertheless, he says, "it provides the state of the art in terms of our understanding of the effects of the introduction of massive amounts of CO2 on surface ocean ecosystems."
That's probably bad news for modern nannoplankton—and other shell-building microscopic life, such as foraminifera. Foraminifera responded similarly to the Aptian event, Erba says, although "data are still sparse." Modern day experiments agree with the fossil record: High CO2 levels in lab tests prompt "selective coccolith malformation, dwarfism and decrease in calcification," Erba notes, whereas these results have been conflicting at times, Bralower adds.
Regardless, the shells of at least one modern foraminifera in the Southern Ocean are already smaller than those of their ancestors from a mere century ago. And the modern buildup of atmospheric CO2 is happening far faster than these ancient episodes. "The current rate of ocean acidification is about a hundred times faster than the most rapid events" in the geologic past, notes marine geologist William Howard of the Antarctic Climate and Ecosystems Cooperative Research Center in Hobart, Tasmania. Plus, the direct impacts of global warming may complicate the picture—just as modern coral suffer from increased bleaching thanks to warmer ocean temperatures as well as the reduced carbonate exoskeleton–building capacity brought on by ocean acidification. Bralower adds: "The big question is whether modern species will be able to adapt to what I expect will be much more rapid pH reduction in coming centuries."
This transformation of the tiny shell-forming creatures that are the basis of the food chain or, like corals, provide the very habitats that allow other species to thrive will unsettle the oceans. And, as this study suggests, recovery from ocean acidification is likely to take millennia—relying as it does on the steady, slow weathering of continental rock to flush more carbonate into the oceans. "If this and other studies' conclusions are correct," Howard notes, "the ocean's recovery will take hundreds of thousands of years."
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17 Comments
Add CommentThe article does not tell us how much ice existed during this period of the Mesozoic era.
Reply | Report Abuse | Link to thisWhen you get localised heating, currents develop to even-out the temperature. When you have ice temperature differentials will remain small. Remember the latent heat of ice is approximately 80 calories per gram, which otherwise would heat water from 20C to 100C without vaporising any. The second law will rule supreme though gravity can interfere.
If there was no ice, then no need for currents to transfer heat to colder ice regions, similarly little up down movements of water between hot and cold layers of water, the hot layer wants to remain on the surface, the colder denser water assisted by gravity wants to stay at the bottom.
Today massive amounts of heat are being taken up by ice. This heat transfer drives ocean currents and atmospheric air movements; our little planet is not heating up that fast in-spite of greenhouse gasses because the energy retained is consumed melting ice. When ice is gone every calorie will heat 1 gram of water by 1C, now you have warming. Still warming will be blocked at 100C when it takes 539 calories to evaporate 1 gram of water at 100C to 1 gram of steam at 100C.
"Nannoplankton"? Is this a new spelling of "nano-plankton" or is it plankton from Nanno in Italy? Or is this a legitimate, but rarely used word?
Reply | Report Abuse | Link to this"vendicar9" Stop quoting the Republicans. You know what happens when you feed the trolls...just look at the commenter above you.
Reply | Report Abuse | Link to thisThe earth will be starting its new cycle in about a year and half. At the beginning of the cycle the earth is ending now - December 2012, there were some very intelligent humans living here, even more intelligent than what we are now...you can tell by the artifacts our scientists are finding, and these humans did something that caused the earth to downsize and dumb them down and it took the earth 26,000 years to correct the damage they did. It has taken the earth this new 26,000 years cycle to almost eliminate their presence...then we modern humans come along and continue the destruction our ancestors left off at and in about one hundred yeas we are now almost at the same point where the earth stopped our ancestors in their destruction. It looks like the earth is going to have to downsize us and dumb us down again. Since we have only been destroying the earth for a little over a hundred years, it will not take the earth another 26,000 years to correct the problems we are causing. The earth will either do to us the way it did our ancestors or it will give us the intelligence and ability to correct our errors. The Mayen and Hopi Indians say that the earth will give us the knowledge and ability, a thousand times more than what we have now, to correct our err in taking care of our environment. Lets keep our fingers crossed in hoping these two Indian tribes are correct.
"Carbon cycle, in biology, the exchange of carbon between living organisms and the nonliving environment. Inorganic carbon dioxide in the atmosphere is converted by plants into simple carbohydrates, which are then used to produce more complex substances. Animals eat the plants and are then eaten by other animals. When these life forms die, they decay, breaking down into, among many other things, carbon dioxide, which returns to the atmosphere. Plants and animals also release carbon dioxide during respiration. Animals and some microorganisms require the carbon-containing substances from plants in order to produce energy and as a source of materials for many of their own biochemical reactions; this cycle is vital to them."
Reply | Report Abuse | Link to thisWhich science is true? The one in which carbon is a crucial part of the life process on earth, or the alarmist garbage expressed in this article?
Carbon cycle, in biology, the exchange of carbon between living organisms and the nonliving environment. Inorganic carbon dioxide in the atmosphere is converted by plants into simple carbohydrates, which are then used to produce more complex substances. Animals eat the plants and are then eaten by other animals. When these life forms die, they decay, breaking down into, among many other things, carbon dioxide, which returns to the atmosphere. Plants and animals also release carbon dioxide during respiration. Animals and some microorganisms require the carbon-containing substances from plants in order to produce energy and as a source of materials for many of their own biochemical reactions; this cycle is vital to them.
Reply | Report Abuse | Link to thisSo which science is real? The one in which carbon is a crucial element in the processes of life on the planet, or the alarmist garbage spewed by this article, as well as the scientific fraudsters at the IPCC?
It's a real, but little used outside the realm of marine biology variant:
Reply | Report Abuse | Link to thishttp://www.paleoportal.org/index.php?globalnav=fossil_gallery§ionnav=taxon&taxon_id=104
http://www.thefreedictionary.com/nannoplankton
http://www.nhm.ac.uk/hosted_sites/ina/
We decided to go with it in this case because that's how it appears in the original research:
http://www.sciencemag.org/cgi/content/abstract/sci;329/5990/428
People like Vendicar and Sen. Inhofe are confused.
Reply | Report Abuse | Link to thisApparently they believe that rhetoric is the same as evidence, and that cheap high school debate is the same as intelligent discussion.
Science will eventually take the day, it always does: the planet is warming due to anthropogenic factors. Deal with it.
Scientific American and Mr. Biello: thank you for another incredible article. Once again journalistic sensationalism and speculation masquerading as science takes real scientific research and tweaks it into another page in the totally unrealistic Stephen King-ish horror story book of global warming . Without a doubt we are indeed in a period of earth-wide warming; however, this is a natural segment of the end of last glacial period about 12,000 +/- years ago. This event is the one with which the collective we are somewhat familiar, and frequently misname the last ice age . It is also the most recent one in at least 11 PREVIOUS MAJOR GLACIAL EVENTS within what is known as the PLEISTOCENE ICE AGE which began give of take 5,000 years 2.588 million years BP (before present). What would eventually become our present day species arose during this period. We had nothing to do with precipitating either this or the previous +/- 5 previous MAJOR ICE AGES. While we may be presently contributing to THIS interglacial period of warming (and most certainly to pollution): we are not the CAUSE of this natural event. In fact, most credible earth SCIENTISTS willingly say that they dont understand all the complex interactions of our living planet which go into creating its weather now, or in the past. There are, however, both hypotheses and theories. (A HYPOTHESIS is a proposed explanation for an observable phenomenon.) (A SCIENTIFIC THEORY is a well-substantiated explanation of some aspect of the natural world, based on A BODY OF FACTS THAT HAVE BEEN REPEATEDLY CONFIRMED THROUGH OBSERVATION AND EXPERIMENt. Such fact-supported theories are not "guesses" but reliable accounts of the real world.)
Reply | Report Abuse | Link to thisIt is despicable for a JOURNALIST to take the life-long learning and efforts of REAL SCIENTISTS and trivialize their work toward actual understanding with what amounts to nothing more than this jumble between science and fiction.
Scientific American and Mr. Biello: thank you for another incredible article. Once again journalistic sensationalism and speculation masquerading as “science” takes real scientific research and tweaks it into another page in the totally unrealistic Stephen King-ish horror story “book of global warming”. Without a doubt we are indeed in a period of earth-wide warming; however, this is a natural segment of the end of last glacial period about 12,000 +/- years ago. This event is the one with which the collective we are somewhat familiar, and frequently misname “the last ice age”. It is also the most recent one in at least 11 PREVIOUS MAJOR GLACIAL EVENTS within what is known as the PLEISTOCENE ICE AGE which began give of take 5,000 years 2.588 million years BP (before present). What would eventually become our present day species arose during this period. We had nothing to do with precipitating either this or the previous +/- 5 previous MAJOR ICE AGES. While we may be presently contributing to THIS interglacial period of warming (and most certainly to pollution): we are not the CAUSE of this natural event. In fact, most credible earth SCIENTISTS willingly say that they don’t understand all the complex interactions of our living planet which go into creating its weather – now, or in the past. There are, however, both hypotheses and theories. (A HYPOTHESIS is a proposed explanation for an observable phenomenon.) (A SCIENTIFIC THEORY is a well-substantiated explanation of some aspect of the natural world, based on A BODY OF FACTS THAT HAVE BEEN REPEATEDLY CONFIRMED THROUGH OBSERVATION AND EXPERIMENt. Such fact-supported theories are not "guesses" but reliable accounts of the real world.)
Reply | Report Abuse | Link to thisIt is despicable for a JOURNALIST to take the life-long learning and efforts of REAL SCIENTISTS and trivialize their work toward actual understanding with what amounts to nothing more than this jumble between science and fiction.
I believe we are missing a big piece of the picture. Every school child knows we breath in oxygen, and exhale.......CO2!! 7 billion souls all exhaling CO2, plus all the other 'animals', that is a horrendous amount of CO2. This little planet was NOT designed to support that population. Your family car produces CO2 only for a short period daily. We are exhaling every 2 seconds, 24 hours a day, for approximately 70 years. Has anyone ever included that in their calculations?? ....just a thought.?
Reply | Report Abuse | Link to thisPicky, picky, picky..................???
Reply | Report Abuse | Link to thisDrivel Mr. Ellis. A fool should be quiet.
Reply | Report Abuse | Link to thisTry a bit of education Mr. Toradze. Truly an uneducated fool should be silent.
Reply | Report Abuse | Link to thisWhatsup, now there's a familiar sounding name for a troll. Look, this climate change stuff is obviously well beyond your grasp. The number of grammatical, logical and factual errors in your post push it way beyond critique. Do yourself and everyone else a favor, make room for someone else who can cope with the intellectual challenge.
Reply | Report Abuse | Link to thisWhatsup: Are you referring to Voltaire’s French satire Candide, ou l'Optimisme? If so, I’m afraid that the relationship to this particular discussion escapes me.
Reply | Report Abuse | Link to thisNow before “going off” again, please read through to the end.
It is very curious to have obviously interested persons throwing around word such as: fool, troll, stupidity, etc. when trying to convince another of their point without having sufficient information themselves. It is also intriguing that such interested persons have done so little real research into the topic which they are trying to discuss. To argue logically, one must have sufficient information on the subject to do so with facts, not conjectures or guesses. Even the author of this debated article is apparently far from well acquainted with the truly enormous scope of climate and climate change, and the lack of one all-encompassing theory that will explain it; which is actually the whole point: NO ONE knows how it all works. Not having the answer(s) and trying to find them is what science in its many shapes and forms is all about.
Again: A HYPOTHESIS is a proposed explanation for an observable phenomenon. A SCIENTIFIC THEORY is a well-substantiated explanation of some aspect of the natural world, based on A BODY OF FACTS THAT HAVE BEEN REPEATEDLY CONFIRMED THROUGH OBSERVATION AND EXPERIMENT. Such fact-supported theories are not "guesses" but reliable accounts of the real world.
If you truly care about this subject, study and learn from scientist rather than journalists; then argue your case from a point of strength rather than weakness: YOU REALLY CAN THEN BEGIN TO MAKE A DIFFERENCE.
Some geo-engineers want to spray sulphur dioxide in the high atmosphere to fight off climate change.
Reply | Report Abuse | Link to thisIronic when you see the worldwide efforts used in the past few decades to combat acid rains.
Mr./Mrs./Ms Whatsup:
Reply | Report Abuse | Link to thisExcuse me: for a moment there due to your mention of Candide, I actually thought that you might be intelligent and literate – pardon my error.
Is it remotely possible that you, in fact, remember 25 years ago as an adult? If so, then you undoubtedly remember that there was just as much, if not more wailing and gnashing of teeth over “climate predictions” back then. “The sky is falling” is as old as man – or Chicken Little.
As always, throughout history, it is not about right or left, up or down, or even center: IT IS ABOUT POWER AND MONEY AND ARROGANCE. Freedom? I am sorely afraid that what we so fondly think of as freedom may have already been bought. It may already be too late to “put your money where your mouth is” and ‘put your life on the line”; if so, that is the way it is going to be until we destroy ourselves: not the Earth, US. The Earth has managed to survive quite nicely for over four and a half billion years, and survived many catastrophes. Man in all his arrogance is hardly likely to do more than destroy himself. The roaches and rats are waiting in the wings for their turn to “rule the Earth”.
Are you afraid? You should be. I am. Extinction was not on the top 10 things that I wanted to do with my life; but …
Oh, yes. So far, we still have freedom of speech – go for it! As with authoring Candide, Voltaire is also attributed with the quote: “I may not agree with what you say but I will defend to the death your right to say it.”