Ancient “Hyperthermals” a Guide to Anticipated Climate Changes
Scripps researchers document the history of sudden global warming events, impacts on marine life
By Mario Aguilera, Scripps Institute News (h/t to Dr. Leif Svalgaard)
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| Sediment samples in the lab of Richard Norris obtained by the Ocean Drilling Program reveal the mark of “hyperthermals,” warming events lasting thousands of years that changed the composition of the sediment and its color. The packaged sediment sample on the left contains sediment formed in the wake of a 55-million-year-old warming event and the sample on the right is sediment from a later era after global temperatures stabilized. |
Bursts of intense global warming that have lasted tens of thousands of years have taken place more frequently throughout history than previously believe, according to evidence gathered by a team led by Scripps Institution of Oceanography, UC San Diego researchers.
Richard Norris, a professor of geology at Scripps who co-authored the report, said that releases of carbon dioxide sequestered in the deep oceans were the most likely trigger of these ancient “hyperthermal” events. Most of the events raised average global temperatures between 2° and 3° Celsius (3.6 and 5.4° F), an amount comparable to current conservative estimates of how much temperatures are expected to rise in coming decades as a consequence of anthropogenic global warming. Most hyperthermals lasted about 40,000 years before temperatures returned to normal.
The study appears in the March 17 issue of the journal Nature.
“These hyperthermals seem not to have been rare events,” Norris said, “hence there are lots of ancient examples of global warming on a scale broadly like the expected future warming. We can use these events to examine the impact of global change on marine ecosystems, climate and ocean circulation.”
The hyperthermals took place roughly every 400,000 years during a warm period of Earth history that prevailed some 50 million years ago. The strongest of them coincided with an event known as the Paleocene-Eocene Thermal Maximum, the transition between two geologic epochs in which global temperatures rose between 4° and 7° C (7.2° and 12.6° F) and needed 200,000 years to return to historical norms. The events stopped taking place around 40 million years ago, when the planet entered a cooling phase. No warming events of the magnitude of these hyperthermals have been detected in the geological record since then.
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| Richard Norris in his lab with ancient sediments obtained by the Ocean Drilling Program reveal the mark of “hyperthermals,” warming events lasting thousands of years that changed the composition of the sediment and its color. The dark color in the large sediment core sample at left depicts the onset and aftermath of a 55-million-year-old warming event when changes in ocean temperatures altered the composition of marine life. |
Phil Sexton, a former student of Norris’ now at the Open University in the United Kingdom, led the analysis of sediment cores collected off the South American coast. In the cores, evidence of the warm periods presented itself in bands of gray sediment layered within otherwise pale greenish mud. The gray sediment contained increased amounts of clay left after the calcareous shells of microscopic organisms were dissolved on the sea floor. These clay-rich intervals are consistent with ocean acidification episodes that would have been triggered by large-scale releases of carbon dioxide. Large influxes of carbon dioxide change the chemistry of seawater by producing greater amounts of carbonic acid in the oceans.
The authors concluded that a release of carbon dioxide from the deep oceans was a more likely cause of the hyperthermals than other triggering events that have been hypothesized. The regularity of the hyperthermals and relatively warm ocean temperatures of the period makes them less likely to have been caused by events such as large melt-offs of methane hydrates, terrestrial burning of peat or even proposed cometary impacts. The hyperthermals could have been set in motion by a build-up of carbon dioxide in the deep oceans caused by slowing or stopping of circulation in ocean basins that prevented carbon dioxide release.
Norris noted that the hyperthermals provide historical perspective on what Earth will experience as it continues to warm from widespread use of fossil fuels, which has increased carbon dioxide concentrations in the atmosphere nearly 50 percent since the beginning of the Industrial Revolution.
Hyperthermals can help scientists produce a range of estimates for how long it will take for temperatures to fully revert to historical norms depending on how much warming human activities cause.
“In 100 to 300 years, we could produce a signal on Earth that takes tens of thousands of years to equilibrate, judging from the geologic record,” he said.
The scientists hope to better understand how fast the conditions that set off hyperthermals developed. Norris said that 50 million year old sediments in the North Sea are finely layered enough for scientists to distinguish decade-to-decade or even year-to-year changes.
Co-authors of the paper include researchers from the National Oceanography Centre Southampton at the University of Southampton in England and the Center for Marine Environmental Sciences, University of Bremen, Germany.
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“2° and 3° Celsius (3.6 and 5.4° F), an amount comparable to current conservative estimates of how much temperatures are expected to rise in coming decades as a consequence of anthropogenic global warming”
(sigh) I don’t expect any such rise “as a consequence of anthropogenic global warming”, mainly because I have yet to see any evidence of “anthropogenic global warming” at all. Wish I knew where to get some of what these “expecters” are smoking.
But it looks like the alarmists now have a new scare word to play with. Anthony, you should offer a small prize for your first correspondent to spot the phrase “anthropogenic hyperthermal event” or similar. (Except this mention here, of course.)
Counting down. 3 … 2 … 1 …
onion2 says:
March 17, 2011 at 2:30 am
I think most of the commenters on this thread expose thier bias by their whipjerk reaction to having to find a reason to dismiss the study.
onion2 says:
March 17, 2011 at 2:34 am
Man’s contribution isn’t puny. CO2 levels have increased by 40% since pre-industry.
Richard Norris, a professor of geology at Scripps who co-authored the report, said that releases of carbon dioxide sequestered in the deep oceans were the most likely trigger of these ancient “hyperthermal” events.
Phil Sexton,………….. These clay-rich intervals are consistent with ocean acidification episodes that would have been triggered by large-scale releases of carbon dioxide.
=====================================================
Onion, you’re gonna have to help me with your reasoning process.
First you snark about everybody here and their inability to understand the validity of the work. Then, you go on about “man’s contribution”, quoting a %40 increase.
Oddly, both Morris and Sexton refer to oceanic release of sequestered CO2. Oh, wait, we know this process isn’t happening now……..
Mods, I’ve another one that’s in moderation hell!
Dr. Svalgard points out that the authors did appear to relate their results to the astronomical periodicities. I have not had time to dig up the article nor the supplementary material. Perhaps someone who has can answer if they discussed the eccentricity maxima and minima. Eccentricity minima and maxima occur every fourth cycle offset by half a 4th cycle, or 200kyrs. So, in 200kyrs we will be at another maxima, another 200kyrs beyond that (400kyrs from now), we will be at another minima, and so on.
Interestingly, the 4th cycle maxima correlate rather well with hominid evolution:
“An examination of the fossil record indicates that the key junctures in hominin evolution reported nowadays at 2.6, 1.8 and 1 Ma coincide with 400 kyr eccentricity maxima, which suggests that periods with enhanced speciation and extinction events coincided with periods of maximum climate variability on high moisture levels.”
state Trauth, et al (2009) in Quaternary Science Reviews. As it turns out, periods of wet maximum climate variability (in modern lingo, global warming/global cooling correctly re-branded as climate change), cook-up the larger braincases. We went from 500-550cc braincases 2.8 mya to the average of about 2,500cc today in the most rapid encephalization of any mammal in the fossil record.
So in consideration of periods in the 400ky range, one would at least be wise to also consider the eccentricity minima and maxima. Since I do not have the time at the moment to read their work, perhaps someone can opine if they did. Because failure to do so might not, well, you know, be human……..
onion2 says:
March 17, 2011 at 2:34 am
Paul R says:
March 16, 2011 at 8:44 pm
“There is that little scale issue again cropping up in Dick Norris’s mud study that must essentially turn mankind’s puny contribution into the Chuck Norris of molecules as usual.
Ka-ching $.”
Man’s contribution isn’t puny. CO2 levels have increased by 40% since pre-industry.
And before anyone wheels out the tired and debunked “humans only emit 3% of CO2″. That 40% increase is part of the 3% accumulating year after year after year. Adds up.
CO2 is currently at millions of year highs so claims on the internet that human CO2 emissions are somehow too small to mean anything is dishonest.
Onion – go and read Henry’s Law. One of the classical gas laws.
CO2 will not build up as you believe it will. As its vapor pressure rises so will the rate of dissolving into the oceans. Clouds and rain rapidly wash CO2 out of the atmosphere and most studies show a life in the atmosphere of ~5 years. Remember the rate it dissolves increases with its vapor pressure.
I haven’t read all the comments, but I scanned most of them and I didn’t see anyone mention the obvious complaint I have with this study (and most other core studies as well):
He used one set of core samples, from one location, and then jumped to global conclusions. The changes he is seeing could be due to a nearly infinite number of various regional conditions. Changes in ocean currents, river outlets, wind/dust deposition variations, rainfall patterns, nearby seafloor shape changes like coral reefs and volcanic mountainbuilding, etc, etc, etc. Unless you can get enough samples from other locations so that you can eliminate other explanations, then you can’t make any conclusions at all. You can only make the observation that something changed at this location, which led to a change in sediment.
Oh by the way. Why doesn’t he admit that changes in the relationship between the sun and earth could also explain climate changes? Answer: because that doesn’t fit the preconceived notions he was trying to support before he started this study.
One of the more interesting things about the PETM can be found here in Texas. Right around the time of the PETM, the Wilcox formation was depositing sand and mud into what we call the Gulf of Mexico. In apparently a very short period of (geologic) time, a channel cut was made in the shelf sediments that ended up being around 65 miles long, up to 12 miles wide and in some places 3,000 feet deep. It’s often called the “Grand Canyon of Texas”. It’s called the “Yoakum Channel”. Even more amazing, faster than it was cut, the channel was then filled in, mostly with mud.
Unfortunately, you can’t visit the Yoakum Channel, as it’s buried under 6-8 thousand feet of additional sediment.
Was this canyon caused by a massive lowering and then a quick rise in sea level, or was it just a submarine canyon formed by processes unrelated to sea level change? Perhaps a combination? Was the Yoakum Channel formed at the same time Wilcox aged reservoir oil sands were deposited 150 miles further away in the Gulf from the traditional Wilcox delta systems? Oil finders working both the onshore and the very deep offshore Gulf of Mexico will tell you the Wilcox formation still holds a lot of questions that are not easily answered.
Alexander K says:
March 17, 2011 at 2:06 am
“…Or have I missed something simple and obvious?…” You raise a good point. Mostly, the oceanic crust is a few hundred thousands to millions of years old (subduction/obduction causing their removal from the sea floor). Not tens of millions of years, which is implied in the article above. Has anyone actually read the paper? Where did they find these (presumably) ancient sea floor sediments?
R. Gates,
“Now, how will the AGW skeptics find some way to poke holes in this study?”
It’s just speculation R. Full of ‘coulds’ and ‘consistent withs’. What’s to poke?
More crap “science”. In short: Speculation.
@R. Gates,
They didn’t show that CO2 had any involvement at all. All they showed was that there were periods in the Earth’s past a lot hotter than now. Everything else is pure speculation and hand waving on their part.
Common chemistry already shows that as a liquid heats up, its ability to dissolve gasses per unit volume decreases, and those gasses are released. Volcanoes are also a great source of all sorts of gasses, some far, far more potent than CO2 could dream to be. We know the Earth used to be far more volcanic than it is now, so the most likely speculation to make is that volcanism was the primary driver of these hyperthermals. There are many other possibilities too, but this seems most correlated with all the evidence about the past that we know.
to R Gates:
“They didn’t show that CO2 had any involvement at all. All they showed was that there were periods in the Earth’s past a lot hotter than now. Everything else is pure speculation and hand waving on their part”
They can’t possibly make even that claim. I don’t think a sample from one place says anything about global conditions.
To Philip Fink:
“It would be interesting to see the original submitted paper and then the reviewer comments”
I can’t find any evidence that this paper was published in a journal or peer reviewed. This is as credible as a love letter to my fiance.
Ian W says:
Yes, some of it will dissolve in the oceans, but not all of what is added. That is why about half of the CO2 from fossil fuel emissions is remaining in the atmosphere.
As for the half-life in the atmosphere, as Willis Eschenbach among others has pointed out here, that is not the correct value to use to characterize how long it takes for a spike in CO2 levels to decay. The short half-life is because there are fast exchanges with the biosphere and the ocean mixed layer. However, transfer of CO2 to the deep oceans (or into land rock formations) takes much longer. Hence, what you have is this: When you add a slug of CO2 to the atmosphere (from a place where it has been sequestered…like fossil fuels are), then it rapidly gets partitioned between the atmosphere, biosphere, and ocean mixed layer. However, the elevated levels of CO2 in this subsystem persists for a much longer time…It is a slow and non-exponential decay.
Gary Swift says:
Apparently, you missed this line in the press release: “The study appears in the March 17 issue of the journal Nature.” Nature and Science are generally considered to be the two top peer-reviewed general science journals on the planet. It doesn’t mean everything in them turns out to be correct, but it does mean that it should be taken quite seriously.
Cart before the horse?
Vostok shows co2 increase comes after a rise in temps (~900 years after). Am I missing something here?
This paper:
http://www.cosis.net/abstracts/EGU2007/09087/EGU2007-J-09087.pdf?PHPSESSID=04ed1917c18da3a5df0aa78653712094
states:
The North Atlantic Igneous Province (NAIP) represents the 3rd
largest magmatic event on Earth for the last 150 Ma. The NAIP formed during two
major magmatic phases: a pre-break-up phase (62-58 Ma) and a synbreakup phase
(56-54 Ma) contemporaneous with the onset of North Atlantic sea floor spreading.
The synbreakup phase (56-54 Ma) of the ‘3rd largest magmatic event on Earth for the last 150Ma’ seems to straddle the ’55-million-year-old warming event’ referred to in the caption accompanying the photo above.
Could there be a connection?
Joel Shore says:
“Yes, some of it will dissolve in the oceans, but not all of what is added. That is why about half of the CO2 from fossil fuel emissions is remaining in the atmosphere.”
Provide testable, reproducible, empirical evidence showing that CO2, specifically, is causing global damage. And with the money at stake, it had better be convincing.
Otherwise, admit that CO2 is a harmless trace gas, and that all the wild-eyed alarmist predictions of runaway global warming are bunkum, and the scientific method is nowhere to be found among the incestuous grant sucking climate clique.
“Richard Norris, a professor of geology at Scripps who co-authored the report, said that releases of carbon dioxide sequestered in the deep oceans were the most likely trigger of these ancient “hyperthermal” events. Most of the events raised average global temperatures between 2° and 3° Celsius (3.6 and 5.4° F), an amount comparable to current conservative estimates of how much temperatures are expected to rise in coming decades as a consequence of anthropogenic global warming. Most hyperthermals lasted about 40,000 years before temperatures returned to normal.”
Excuse the stupid question, but should not the periodic hyperthermal data be included within the range of natural climate variability?
Dave in Delaware says:
March 16, 2011 at 9:50 pm
For example: The mid Atlantic rift is dead center in the undersea ‘return’ leg of the thermohaline conveyor. CO2 added there would cycle back up to the surface in the Pacific and Indian oceans centuries later.
Thanks Dave. I’m working on making a more comprehensive argument from my “Earth burps” comment and appreciate the feedback. Food for thought.
=================================================
JimF says:
March 16, 2011 at 11:20 pm
Thanks Jim, you’re right I wasn’t properly differentiating between continental and oceanic crust. I need to better incorporate what you’ve rightly pointed out.
“The Late Cretaceous and Early Paleocene exhibited some of the greatest oceanic spreading rates that (to my knowledge) have been measured or estimated. The Atlantic Ocean opened in a flash, so to speak.”
Thanks again, I’ll do more research on those events.
====================================================
Alexander K raises points I’ve been interested in too.
I have thoughts on a modified Expanding Earth theory here: http://cultofthecarboncow.com/?p=1670 Comments are closed but if you share an interest, I’d open another thread for emails and comments.
The authors might be right, or they might be wrong!
Joel Shore said: “…When you add a slug of CO2 to the atmosphere (from a place where it has been sequestered…like fossil fuels are), then it rapidly gets partitioned between the atmosphere, biosphere, and ocean mixed layer. However, the elevated levels of CO2 in this subsystem persists for a much longer time…It is a slow and non-exponential decay.”
Yes, it persists until it is fixed into calcium carbonate by marine micro-organisms whose skeletons sink to the bottom of the ocean where a portion are preserved for a very long time in the ultimate CO2 sink: Limestone!
My guess is the amount of CO2 that is ‘sequestered’ into the world’s known limestone formations is orders of magnitude greater than any of the other ‘subsystems’ you are considering.
Scott Ramsdell, you are correct, this is natural variability, part of the natural climate “noise”. Only in just the past 20 years have we realized that the natural climate is abrupt, dramatic and apparently unavoidable. I often joke with folks heavily bent on the AGW hypothesis that wouldn’t it be wonderful, we somehow find a way to squelch CO2 emissions, scrub the atmosphere of it to whatever level they think appropriate, and completely quash the 2007 AR4 worst case 0.59 meter sea level rise. While we are slapping ourselves on the back, drinking non-carbonated champagne (of course) sea level suddenly shoots up 20 meters anyway, like it did right at the end of the last interglacial, or maybe 20 meters, like occurred during the Holsteinian (MIS-11) four interglacials back.
As one might expect, this tends to fall on deaf ears. One of the first order problems of AGW adherents is not so much a lack of perspective, but the lack of an ability to perceive perspective. Because once a thing has gelled in the minds of homo sapiens (think religion for example) it typically takes something on the order of a crisis of faith to net a different conclusion. A thing which doesn’t seem to happen all that often. As a practicing scientist that must frequently deal with the movers and shakers of major corporations caught in the vortex of complex environmental nightmares, finding a way to “plug-in” quickly to their thought channels, and at their perceived level of understanding, often needing to raise it just as quickly, is almost always the most difficult challenge. As with communicating things climate.
I have not found the golden key here yet, but often a properly delivered shock will create a crack, just wide enough to allow a single contrary thought to enter the active level of consciousness. I am often to be heard at the outset of a climate encounter immediately espousing my sincere hope that they are right about CO2. In fact they had better be right. Continuity of civilization probably depends on their being right! What other solution can they propose that will extend the eventual end of the now very long-in-the-tooth Holocene? “What, do tell, is the Holocene?” is not an atypical response. Why, its the interglacial, you know the bookends of the ice ages, in which all of human civilization has occurred! Only cave paintings have been found post 10,000 years ago, and the Holocene is now about 11,500 years old, exactly half of the present precessional cycle. 5 of the last 6 interglacials have each lasted about half a precessional cycle! If you can think of another way to keep the miles thick ice sheets that have extended as far south as Kansas from forming in the eventual near future, I would be most interested in hearing it.
Works on intelligent people. Sometimes.
But on to another commenter’s question as to why we do not see this in the ice core data. Well, the useful recovered ice from Antarctica goes many times further back than Greenland, and it only gets us back to right about MIS-19, something like 800kya. So about 1/70th of the way back in times towards the PETM. And yes, so far the consensus seems to be that the temperature excursions known as ice age terminations preceded the GHG rises by something on the order of 800-1000 years in the available ice cores. In the B and C class Dansgaard-Oeschger oscillations, same order, but the GHGs rise faster, with the difference more on the order of decades to a few centuries. D-O events average 1500 years long and 8-10 degrees C and have ramped as high as 19C!
And we are not talking 200,000 years to slope down 7C, this happened 24 times in the last 100,000 years! So I take your 7C and raise you 12C and call! Evidence for D-O events has been credibly reported in varved sedimentary rocks 680 million years old. Dome. So at 1500 years, that would be a half million or so D-O events. You lose.
Smokey says:
March 17, 2011 at 11:21 am
Joel Shore says:
“Yes, some of it will dissolve in the oceans, but not all of what is added. That is why about half of the CO2 from fossil fuel emissions is remaining in the atmosphere.”
Provide testable, reproducible, empirical evidence showing that CO2, specifically, is causing global damage. And with the money at stake, it had better be convincing.
Otherwise, admit that CO2 is a harmless trace gas, and that all the wild-eyed alarmist predictions of runaway global warming are bunkum, and the scientific method is nowhere to be found among the incestuous grant sucking climate clique.
Smokey,
Joel Shore’s statement is a scientifically correct description of what has happened to the CO2 emitted by human industrial sources. If you believe this to be incorrect, provide some backup.
Despite the protestations of the right wing Global Warming skeptics, there is 150 years of scientific literature supporting the idea that the emissions of CO2 due to human industrial sources will strongly affecting the earth’s climate and that natural emissions of CO2 have done that in the past.
The fact that people are educated , paid to do climate science, and learn from one another, and challenge one another, is the way science has always been done. This pattern has resulted in a lot of scientific progress.
It seems that some people are ideologically driven to deny the results of climate science because the conclusions conflict with their prejudices. This is also true of biology. In the US, 40% of people believe that the human race was created by God less than 10,000 years ago, despite the evidence that the homo sapiens fossils 190,000 years old , and human precursor fossils 3 million years old have been found; and evolution is the basis of biological science.
James Sexton says,
However, like most good sarcasm, it was rooted and truth. James Overland of NOAA did indeed forward a contrivance called Warm Arctic Cold Continents as an explanation for this winter’s cold. Which is odd, because at Goddard’s site, we too, independently defined the process as warmcold. My use Dr. Syme as an obscure reference to the Orwellian nature of both explanations. In fact, warmcold was contrived with Orwell’s 1984 in mind. Syme would be the co-worker of Winston Smith. “He is too intelligent. He sees too clearly and speaks too plainly.”
Both contrivances are as credible as any other explanation which was posited as an explanation for a process described in the paper.
James
Actually Overland’s explanation seems quite credible, and he predicted the recent winter cold snap in North America before it happened. Look at this press release from the summer of 2010.
http://www.sciencedaily.com/releases/2010/06/100611093710.htm
He isn’t the only climate scientist to describe this phenomenon. It was simulated and described in even more detail by Judah Cohen, who also predicted it in advance.
http://www.nytimes.com/2010/12/26/opinion/26cohen.html
Weather is interesting and complex, and we should respect those who provide clear explanations of the forces at work. Satire works only if the object is ignorant or mistaken. People who satirize what they don’t understand can look foolish.
Ian W says:
” Onion – go and read Henry’s Law. One of the classical gas laws.
CO2 will not build up as you believe it will. As its vapor pressure rises so will the rate of dissolving into the oceans. Clouds and rain rapidly wash CO2 out of the atmosphere and most studies show a life in the atmosphere of ~5 years. Remember the rate it dissolves increases with its vapor pressure.”
You are leaving out the fact that as temperature increases, the solubility of gases in water decreases.
http://en.wikipedia.org/wiki/File:SolubilityVsTemperature.png
When the ocean surface layer becomes warmer, the solubility of CO2 goes down, , and the rate of removal of CO2 by the oceans goes down. It seems as if this is already happening in the southern ocean. In this case cold water from the ocean depths which holds a large amount of CO2 comes to the surface, and gets warmer, and can’t absorb CO2 from the atmosphere.
http://www.newscientist.com/article/dn17385-ozone-hole-has-unforeseen-effect-on-ocean-carbon-sink.html
In addition, as the temperature of the ocean rises, the maximum concentration of CO2 decreases so much that the oceans will then emit CO2. This causes an increase in the greenhouse effect, and heats the ocean further until a new equilibrium is reached at a higher concentration of CO2 in the atmosphere.
http://www.skepticalscience.com/co2-lags-temperature.htm