“The more interesting and potentially controversial result is that our data indicate surface water temperatures during a part of the Medieval Warm Period that are similar to today’s…”
“Although there are significant uncertainties with our own reconstruction, our work raises the idea that perhaps even the Northern Hemisphere temperature reconstructions need to be looked at more closely.”
Woods Hole Oceanographic Institution: News Release : New Temperature Reconstruction from Indo-Pacific Warm Pool
The First Word in an Unfolding Story
Media Relations Office
93 Water Street MS #16
Woods Hole Oceanographic Institution
A new 2,000 year long reconstruction of sea surface temperatures (SST) from the Indo-Pacific warm pool (IPWP) suggests that temperatures in the region may have been as warm during the Medieval Warm Period as they are today.
The IPWP is the largest body of warm water in the world, and, as a result, it is the largest source of heat and moisture to the global atmosphere, and an important component of the planet’s climate. Climate models suggest that global mean temperatures are particularly sensitive to sea surface temperatures in the IPWP. Understanding the past history of the region is of great importance for placing current warming trends in a global context.
The study is published in the journal Nature.
In a joint project with the Indonesian Ministry of Science and Technology (BPPT), the study’s authors, Delia Oppo, a paleo–oceanographer with the Woods Hole Oceanographic Institution, and her colleagues Yair Rosenthal of Rutgers State University and Braddock K. Linsley of the University at Albany-State University of New York, collected sediment cores along the continental margin of the Indonesian Seas and used chemical analyses to estimate water past temperatures and date the sediment. The cruise included 13 US and 14 Indonesian scientists.
“This is the first record from the region that has really modern sediments and a record of the last two millennia, allowing us to place recent trends in a larger framework,” notes Oppo.
Global temperature records are predominantly reconstructed from tree rings and ice cores. Very little ocean data are used to generate temperature reconstructions, and very little data from the tropics. “As palaeoclimatologists, we work to generate information from multiple sources to improve confidence in the global temperature reconstructions, and our study contributes to scientists’ efforts towards that goal,” adds Oppo.
Temperature reconstructions suggest that the Northern Hemisphere may have been slightly cooler (by about 0.5 degrees Celsius) during the ‘Medieval Warm Period’ (~AD 800-1300) than during the late-20th century. However, these temperature reconstructions are based on, in large part, data compiled from high latitude or high altitude terrestrial proxy records, such as tree rings and ice cores, from the Northern Hemisphere (NH). Little pre-historical temperature data from tropical regions like the IPWP has been incorporated into these analyses, and the global extent of warm temperatures during this interval is unclear. As a result, conclusions regarding past global temperatures still have some uncertainties.
Oppo comments, “Although there are significant uncertainties with our own reconstruction, our work raises the idea that perhaps even the Northern Hemisphere temperature reconstructions need to be looked at more closely.”
Comparisons
The marine-based IPWP temperature reconstruction is in many ways similar to land temperature reconstructions from the Northern Hemisphere (NH). Major trends observed in NH temperature reconstructions, including the cooling during the Little Ice Age (~1500-1850 AD) and the marked warming during the late twentieth century, are also observed in the IPWP.
“The more interesting and potentially controversial result is that our data indicate surface water temperatures during a part of the Medieval Warm Period that are similar to today’s,” says Oppo. NH temperature reconstructions also suggest that temperatures warmed during this time period between A.D. 1000 and A.D. 1250, but they were not as warm as modern temperatures. Oppo emphasizes, “Our results for this time period are really in stark contrast to the Northern Hemisphere reconstructions.”
Reconstructing Historical Temperatures
Records of water temperature from instruments like thermometers are only available back to the 1850s. In order to reconstruct temperatures over the last 2,000 years, Oppo and her colleagues used a proxy for temperature collected from the skeletons of marine plankton in sediments in the Indo-Pacific Ocean. The ratio of magnesium to calcium in the hard outer shells of the planktonic foraminifera Globigerinoides ruber varies depending on the surface temperature of the water in which it grows. When the phytoplankton dies, it falls to the bottom of the ocean and accumulates in sediments, recording the sea surface temperature in which it lived.
“Marine sediments accumulate slowly in general — approximately 3 cm/yr — which makes it hard to overlap sediment record with instrumental record and compare that record to modern temperature records,” says Oppo. “That’s what is different about this study. The sediment accumulates fast enough in this region to give us enough material to sample and date to modern times.”
The team generated a composite 2000-year record by combining published data from a piston core in the area with the data they collected using a gravity corer and a multi-corer. Tubes on the bottom of the multi-corer collected the most recently deposited sediment, therefore enabling the comparison of sea surface temperature information recorded in the plankton shells to direct measurements from thermometers.
Oppo cautions that the reconstruction contains some uncertainties. Information from three different cores was compiled in order to reconstruct a 2,000-year-long record. In addition sediment data have an inherent uncertainty associated with accurately dating samples. The SST variations they have reconstructed are very small, near the limit of the Mg/Ca dating method. Even in light of these issues, the results from the reconstruction are of fundamental importance to the scientific community.
More Questions to Answer
The overall similarity in trend between the Northern Hemisphere and the IPWP reconstructions suggests that that Indonesian SST is well correlated to global SST and air temperature. On the other hand, the finding that IPWP SSTs seem to have been approximately the same as today in the past, at a time when average Northern Hemisphere temperature appear to have been cooler than today, suggests changes in the coupling between IPWP and Northern Hemisphere or global temperatures have occurred in the past, for reasons that are not yet understood. “This work points in the direction of questions that we have to ask,” Oppo says. “This is only the first word, not the last word.”
The US National Science Foundation and the WHOI Ocean and Climate Change Institute provided funding for this work.
The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans’ role in the changing global environment.
h/t to WUWT reader Glenn
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How about
Gore, Hansen, Mann & Monbiot
The Four Horsemen of the Thermocalypse
(I thought that we needed a bit more of an international flavor)
“So much for claim that MWP was localized in Europe only, as Wiki still boldly claims.”
You could possibly tell that to the Dorset people … if they were still alive. The Inuit and Thule drove them out of the Arctic into oblivion when the climate warmed during the MWP.
P Walker (10:19:20) :
CAPT CHARLES : Methinks the Woods Hole jar runneth over with AGW cookies already . Maybe they decided to blow some of them on real science , for a change .
Woods Hole Oceanographic Institution is a scientific institute on Cape Cod. http://www.whoi.edu/
Woods Hole Research Center is an activist organization, arguably created to trade off the name-recognition of WHOI and certainly to promote AGW hysteria.
Plenty of mainstream journalists give the impression of not knowing the difference between the two…
On the other hand, WHOI’s 2007 report included the following gem:
Particularly noteworthy is Hal Caswell’s contribution to the
International Polar Bear Study Team for the U.S. Department of
the Interior. Caswell and colleague Christine Hunter of the University
of Alaska (a former postdoctoral scientist at WHOI) took
data collected by the U.S. Geological Survey on polar bear mortality
rates, birth rates, life cycle characteristics, and habitats and
incorporated it into mathematical models. By linking their models
with projections of sea ice conditions in the Arctic, they were able
to demonstrate the critical importance of sea ice and climate
change to the population success of the polar bear. Recently the
Department of Interior listed the polar bear as threatened with
extinction because of the decline in sea ice, making it the first species
to be so designated as a result of global warming.
— Judith E. McDowell, Department Chair
Nonetheless, WHOI is the more scientific of the two institutions, and generally less likely to create AGW alarmist headlines for sport.
Tom G(ologist) (11:16:25) :
The damage to the credibiilty of science in general is what concerns me most. I am also involved in the (anti)evolution wars – anti-evolutionists are continually making heavy water about evolutionary theory being nothing more than an article of faith, a belief system, in the same way relgion is. Once it is seen by the general populace that so-called AGW science IS nothing more than a belief system with no real underpinnings of science, expect a new spate of anti-evolution activity in your schools.
I have been trying to make sense to some of the bloggers on evolution for years to not tie the two topics together – people like P.G. Myers are wont to make statements such as “People who don’t accept evolution also don’t accept global warming” It’s an idiotic and sanctimonious attitude for a sicentist, but they have tied the two together – once one is determined to be a belief system…..
Anti-evolution is a backlash against those who claim that evolution negates any Creator. This is incorrect, as science is agnostic, not atheistic.
Anti-evolution shows how the world’s education system has failed. People don’t understand the difference between faith and science. Are the two compatible? Many of the greatest scientific minds in history were people of faith. Evolution and faith or only incompatible to those who take their religious texts literally or to those who don’t understand the difference.
Anti-evolutionists know several criticisms of evolution and do not consider the response to those criticisms. They are blind to explaination, debunking and facts that contradict their closely held beliefs. It’s very hard to *prove* macro evolution, which only adds fuel to the fire.
Fanatical AGW apologists incorrectly disparage skeptics as anti-evolutionists, not realizing that they are the ones with closed minds and dogmatic beliefs.
“”” Craig Moore (09:00:26) :
Don’t worry Dr. Running says politics are where the action is at in the new climate change minor program at the University of Montana. See: http://www.montanakaimin.com/index.php/news/news_article/um_offers_unprecedented “””
I had some e-exchanges with Prof Steve Running; about some fooishness that said that trees in the arctic caused global warming by replacing snow that would increase albedo; whereas the trees would absorb the solar energy, and so heat the previously snowy regions.
I pointed out that the trees actually convert the absorbed solar energy (along with some CO2 into wood, instead of “heat”. The thesis was proposed by some otherwise unemployed people at Stanford, and also Lawrence Livermore National labs; maybe even under Nobellist Steve Chu’s tutelage.
Our new energy Czar (Tsar) believes that microbes and yeasts are the energy source of the future, converting wood and hay (cellulose) into gasoline.
Talk about employing the most underpaid workers; but does anybody else besides me see this scheme (scam) as another form of solar energy; free, green, renewable, clean; and consuming oodles of land area.
The September issue of OPN (Optics & Photonics News) carries an article by a Blair L. Unger on Concentrated PhotoVoltaics; which is a polite way of saying that you use cheap optics to replace expensive PhotoVoltaic cells, and concentrate the sunlight into a smaller space (and less solar cell area).
I know a thing or two about Optics, and I don’t know of any way of sucking in solar energy from an extended area that is larger than the aperture of the “cheap”optics. The article has a photo of Solar Power Panels near Albuquerque New Mexico. The panels are tilted up so that each one is face on to the sun. Gee wouldn’t you know it; when you do that, each panel casts a shadow, that blocks a much larger area of the ground, where you can’t put another panel since it would collect no energy. The result is that the dedicated land area is very much larger than the actual collector area, whether it is concentrator Optics or not.
I’m all in favor of the concentrator cell approach, if the optics is cheaper than the solar cells.
When you tip up the cell arrays to face the sun, the obscured area is the same, whether you tilt up a one square km panel, or a one square metre panel. It seems to me, that the larger you make the panels, the more expansive it is to tilt them up, and protect them from 150 year storm winds.
Some people don’t get it; the earth/sun orbital geometry determines the Watts/m^2 of solar power arriving on earth; and using microbes to do the work of making gasoline out of that, doesn’t alter the fundamental areqal inefficiency of the scheme;a nd I somehow doubt the conversion efficiency from bugs to gas is very high; besides somebody has to feed those bugs with somethign else besides wood chips or hay.
Dr Running seemed like a reasonable chap to me; don’t really know why he went in the tank for the greenies. The folks who would wipe out trees for snow, eventually were forced to tone down their silliness.
George
brazil84 (12:22:24) :
The warmists get around it by claiming that the medieval warm period was conveniently limited to areas in which historical records were kept.
That is strangely familiar. The world was once confined to Western Eurasia and N. Africa, flat, and beyond it lay monsters and the sides of the pit to hell.
Such reasoning is devolving back into mythology.
It also is reminiscent of the thinking that Earth lay at the center of the universe, and the Western World alone was civilized.
“”” Steve Schaper (11:15:41) :
I would expect that the proposed(unproven but recorded) destruction of Krakatoa in AD 535, separating the islands of Sumatra and Java into two separate islands, might have changed water flow. Before that, might not the ocean between SumatraJava and Borneo gotten even warmer? “””
You say that Java and Borneo were once one island; My maps say Java is at least 200 miles from Borneo,a dn I somehow doubt that Krakatoa is in between them.
Now Java and Sumatra might easily have been joined at one time, and are now separated by the Sunda Straits. That fictional movie Krakatoa, East of Java, had it all wrong too, since Krakatoa is certainly not East of Java; at least it wasn’t when last I looked.
Time for some geography revisionist history.
George
I am yet to be convinced that taking proxy temperatures, whether by measuring tree rings or compositions of calcium in sediment, is significantly better than reading tea leaves. Indeed it may be a lot worse, since it carries a veneer of scientific credibility that tea leafs do not.
I note that these proxies tell us that the NH MWP was 0.5C cooler than today. That’s a whopping great lot and is contrary to all historical evidence of a period that was warmer than today. If you take the graph at the SST graph seriously, you are forced to conclude that there is something unnatural about the late twentieth century warming by the way it spikes up.
Also, it relates to SST. What about land temperatures? That isn’t mentioned at all.
Harold Ambler : (13:35:23)
Thanks – my bad . Actually , I was confused as I had been under the impression that WHOI was affliated with a university and not privately funded . Certainly WHOI is the “legit” one .
Of course there was a MWP. How can you have Ice Ages, Little Ice Ages and interglacials but not Warm Periods? The ice has to melt sometimes, and that means it gets warmer. Duh. It took the better part of 20,000 years to get rid of the Laurentide Ice Sheet, without which a lot of Ice Blue popsickle mummies would be getting dug up…like the guy they found in the Alps.
And it freezes fast, too. Otherwise we wouldn’t be finding Wolly Mammoths with a bellyful of fresh green grass preserved in Ice.
“Now Java and Sumatra might easily have been joined at one time, and are now separated by the Sunda Straits. ”
Yes, it was Java and Sumatra that became separated by the caldera forming eruption in 535. The impact of the eruption was global. You can read more here about the results of this eruption.
The Moche people in South America saw the end of their civilization at about this time. Life would have been very difficult everywhere but today it would be horrendous. Imagine no grain crops from Canada, the Northern plains of the US or the Eurasian Steppes. Summer frosts across most of North America and Northern Europe. Extremely dry conditions due to greatly reduced solar driven evaporation from the oceans. And billions more mouths to feed. It would be an absolute calamity.
Still on the banging the head off the wall theme … we are now being told by the great Moon (as opposed to the great moon-bat) that the Arctic is melting “even faster than previously thought” (a phrase which in my view should render its user subject to some very immediate and permanent disfigurement).
I seem to have noticed that there are two links on the sidebar of this very site that prove this not to be the case. How are we supposed to win an argument, or even engage seriously, with people who are either fools or knaves when it comes to climatology?
Photosynthesis is an endothermic reaction. It causes a reduction in temperature (as opposed to an exothermic reaction such as the oxidation of sugars in our bodies).
Well, yes and no. All things being equal, the proxies from the MWP would seem to indicate a lower temperature. But what they are really showing is less optimal growing conditions. If, as has been shown from studies of European river sediments, the MWP was warm but dry, the reduction in tree growth could be from lack of water, and not lack of warmth. Based on pollen samples from the period and high alpine altitudes, temperatures were warmer then because certain plants were growing at altitudes where they can not grow today. But if there was prolonged drought, we would see reduced tree ring width even with the warmer temperatures.
What we are seeing today is apparently a very nice period of warm weather AND considerable rainfall across the entire NH. The lakes in the Sierra Nevada, for example, are well (tens of meters) above levels seen fairly recently in this interglacial.
“Global Warming BY Dummies”, by Elizabeth May
http://www.cnsnews.com/news/article/53387
Apparently it’s more of a political book than the science behind Climate Change.
Sam the Skeptic (15:17:29) :
Actually, Sam, it’s freezing up in the Arctic faster than they predicted it would be melting away. I call to everyone’s attention what happened last year when the Arctic Sun set. Our first N. Pacific storm is expected to clip us in NW Calif. on Saturday.
We shall soon have a taste of what another full year of very low Solar Activity has prepared for us.
Something in the post caught my attention. Are the AGW folks basing their position on physical data only in the Northern Hemisphere?
“However, these temperature reconstructions are based on, in large part, data compiled from high latitude or high altitude terrestrial proxy records, such as tree rings and ice cores, from the Northern Hemisphere (NH).”
What about the rest of the world. Are they examining tree rings in Africa, and South America?
You all fail to understand the way Mann’s mind works. He will simply issue a statement claiming that “this research confirms his earlier work as well as the work of his colleagues more recently which has given even more confirmation to his original research”.
He will make no mention of the fact that he confirmed in an interview in 2005 for Scientific American that I wrote about on Climate Audit at the time, that the Medieval Warm Period and the Little Ice Age never happened as global climatic events.
And any attempt to point this out on RealClimate will be summarily deleted with prejudice. Guaranteed.
so even though we have been in a 10+ year solar cool ctcle ocean temps are as warm as they were back then Gee I wonder what is causing it to get so warm ??
I have been swimming and snorkelling in the waters off Bougainville Island (near New Guinea) an area that often shows up on temperature maps as the warmest ocean water in the world. It was a little strange, the sensation was like a warm bath. Even though the sun and humidity there are fierce, going for a swm is only marginally refreshing. Interesting also that the coral reefs there are thriving and beautiful (at temperatures above 33 degrees Celsius). This is worth remembering whenever you hear claims that global warming will destroy the world’s coral reefs. There is no ocean water in the world that is too warm for coral reefs, but there are vast areas that are too cool.
Clearly the NH and IPWP have diverged because of AGW. After all, it happened suddenly when evil humans started AGW.
Actually, maybe yes. Mannmade warming (the Menn are in Asheville, Columbia (the University, not the Cocaine Republic), and East Anglia.) results in a sudden disconnect between the real data and the adjusted data.
How convenient.
“”” George E. Smith (14:16:12) :
“”” Steve Schaper (11:15:41) :
I would expect that the proposed(unproven but recorded) destruction of Krakatoa in AD 535, separating the islands of Sumatra and Java into two separate islands, might have changed water flow. Before that, might not the ocean between SumatraJava and Borneo gotten even warmer? “””
You say that Java and Borneo were once one island; My maps say Java is at least 200 miles from Borneo,a dn I somehow doubt that Krakatoa is in between them.
Now Java and Sumatra might easily have been joined at one time, and are now separated by the Sunda Straits. That fictional movie Krakatoa, East of Java, had it all wrong too, since Krakatoa is certainly not East of Java; at least it wasn’t when last I looked.
Time for some geography revisionist history.
George “””
Am I going nuts or something; or is it the Alzheimers setting in. I would have bet my Wife’s credit card debts, that when I pasted this, the word Sumatra appeared nowhere in it; let alone in the form of Sumatra-Java; it simply said Java and Borneo; i even got up and went to the world map on the wall, just to refresh my memory that Java and Borneo are not even close to each other.
So how did Java suddenly become sumatra/Java, and turn me into a blithering idiot; not only in my cut and paste, but also in the original. Do we have post publication revision here or something ?
George; going daft or something.
Jeff Id-Don’t the reviewers (as Nature is a very very high profile and high impact journal) examine the way proxies have been evaluated? Surely they would, wouldn’t they?
John A-any attempt to get it mentioned on tamino’s open mind will also meet the same “deletion with prejudice”
Ian (17:13:05) : Nature is a high profile and impact journal but it’s reputation is far from deserved these days. And peer review is so passe. The internet is kicking it’s ass. Take for example:
http://www.climateaudit.org/?p=473
Yup, you read correctly. A scientific journal published an essentially fraudulent stem cell paper. Peer review didn’t expose it. Blogs did!
Nature=FAIL.
There are 2 other proxy records that go against Manns work, They are solar activity proxies that some say might be linked to climate. But what people dont seem to be paying attention to is that now both proxy records confirm each other. The detail records of both Carbon 14 and Beryllium 10 (14C & 10Be) can now be compared and the result is beyond doubt.
Full story here:
http://www.landscheidt.info/?q=node/51