Andrew Revkin writes:
Michael Mann can’t be happy about this work.
Here’s a chat with two authors of an important new Science paper examining 10,000 years of layered fossil plankton in the western Pacific Ocean. The paper finds that several significant past climate ups and downs — including the medieval warm period and little ice age — were global in scope, challenging some previous conclusions that these were fairly limited Northern Hemisphere phenomena.
(video follows, an interview with authors)
The study finds that the rise in ocean temperatures in recent decades is far faster than anything seen earlier in the Holocene, the period since the end of the last ice age. But the researchers say that this rise is from a relatively cool baseline. Between 10,000 and 8,000 years ago, at depths between 500 and 1,000 meters, the Pacific Ocean was 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than today. (text from the video description)
The paper is here:
http://www.sciencemag.org/content/342/6158/617
Pacific Ocean Heat Content During the Past 10,000 Years
Yair Rosenthal, Braddock K. Linsley, Delia W. Oppo
Abstract:
Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 ± 0.4°C and 1.5 ± 0.4°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large.
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John W. Garrett said:
October 31, 2013 at 12:02 pm
Chalk up yet another chink in the crumbling edifice of Michael “Piltdown” Mann.
Thank you for that one, this was my laugh-of-the-day!
Piltdown Mann.
+1
How widespread was the Medieval Warm Period? It looks like it was global according to lots of peer reviewed papers.
I have a paper from Michael Mann who said that there is evidence of olives and figs growing in Germany and Greenland warmth as well as graped grown in England well north of their current positions. Can an ‘expert’ here please explain to me what mechanism could cause it to be so warm in Germany, England and Greenland for such a long stretch without the rest of the world generally getting warmer?
This is a couple of years old, I think, but maps papers on the MWP to where in the globe the paper deals with .
It was clearly global.
http://pages.science-skeptical.de/MWP/MedievalWarmPeriod1024x768.html
http://wattsupwiththat.com/2013/10/31/new-paper-shows-medieval-warm-period-was-global-in-scope/#comment-1462668
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I don’t know who said it first but I prefer “Meltdown Mann”. 😎
Along with the polar caps and all that, he seems to have a meltdown anytime someone implies he was wrong.
Here is the Mann paper.
Good article here about that nasty disease, McKibbenitis.
http://notrickszone.com/2013/10/31/green-psychologists-confirm-climate-alarmists-are-making-themselves-mentally-sick-doomer-depression/
milodonharlani says:
October 31, 2013 at 1:48 pm
Steven Mosher says:
October 31, 2013 at 1:21 pm
You don’t get it. CACA advocates have tried to argue that the Medieval Warm Period was restricted to the North Atlantic region. Study after study from around the world has shown this to be a bald-faced lie. Now the western Pacific has been added to that long list.
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I fully agree with Milodonharlani that previous examples of the MWP were restricted to the northern hemisphere, whether real or imagined by many so called AGW fanatics or wishful thinking on their part, however with the MWP showing up in the vast Pacific Ocean this is a whole new adventure never previously verified. In essence – Mann and others are flat out wrong – again.
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If you studied pre-tree-ring-history you’d find the affliction dates back to at least the advent of Caronitis. (And, no, I don’t mean Johnny.)
albertalad says:
October 31, 2013 at 2:53 pm
In the 1960s, Medieval Warm Period evidence was largely restricted to part of the Northern Hemisphere, but already by the 1990s, if not before, the preponderance of observations showed it to be global. Strong evidence came not only from the oceans, but from land sites in Asia, Africa, Antarctica, South America, Australia & New Zealand, & from a range of different proxies.
Many have been cited on this blog before.
For example, here’s the famous New Zealand stalagmite study from 1979:
Wilson, A.T., Hendy, C.H. and Reynolds, C.P. 1979. Short-term climate change and New Zealand temperatures during the last millennium. Nature 279: 315-317.
Opposite side of the world from the North Atlantic region, ie North America & Europe, to which CACA shills would like to restrict the climatic event.
A big thank you to Keith DeHavelle for posting a partial transcript from the video. It has a critical couple of sentences that should be added to the top of the post, because it eviscerates any claim of an unprecedented rate of ocean warming in the last 50 years. It is the same shambolic Marcott incident all over again.
“You could say that we probably have century-scale resolution at best… It’s possible that the sediments just didn’t record similar warmings in the past.” YAIR: The deep ocean tends to average and smooth the record … I think it’s fair to say that it’s unlikely that very rapid changes on the order of, let’s say, years or even decades … would show up in the record.”
Grist has an entirely different take on the journal article. They ignore the worldwide MWP aspect, ignore that the ocean temperature was warmer during MWP, and headline their article “The Pacific Ocean is now warming 15 times faster than it used to”
http://grist.org/climate-energy/the-pacific-ocean-is-now-warming-15-times-faster/
I posted the abstract at HuffPo. That should rile them up.
Steven Mosher says:
from one ocean basin they jump to global conclusions.
No.
From one ocean basin that covers the vast majority of the southern hemisphere, they (meaning Revkin and Watts) correctly conclude that the MWP is indicated to not be “just a Northern Hemisphere event” as is typically claimed by the pudgy goatee crowd.
For one who’s always driving by, you have an awful lot of trouble keeping up.
As someone linked th co2science site has hordes of papers showing the mwp and others. Ive read through scores of them years ago, I certainly saw nothing unprecedented about current changes, actually many records show several periods that changed much faster, and heck early 1900s changed as fast when we had more reliable data. Im shocked this claim stands as well as it does. It certainly doesnt speak well for our scientific institutions.
Plenty of government grants in Australia for climate research. Anyone looking for the MWP there? That might put the cat amongst the pigeons in Mann’s work.
“Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades.”
OYG!!!!
They need to report that in Joules! It has to be something like a bajillion Hiroshima bombs worth of OHC. How did those poor bastards in their loin cloths and balsa wood Kon-tiki boats manage to survive? Surely they burst into flame immediately upon setting sail.
Mosher: “what would folks say if the sediments showed the opposite”
The opposite of what they said. No, wait… are the ‘folks’ climatologists?
Huffpo doesn’t like what I posted it seems.
“Due to the potentially sensitive nature of this article, your comment may take longer to appear publicly.”
In other words, the proposition is not necessarily true (can’t be proven), but is is fair to say such things in a scientific paper anyway. Uh-oh.
Why on earth would anyone think it could warm warmer than today and it would stubbornly stay only in Europe or even the NH. Trenberth is busy chasing a pinball hot spot that appears in Russia, disappears, and then pops up over Australia and then dives down into the ocean deeps!! For Steven Mosher and all of you who would restrict the major warming and cooling periods to only the NH (some even to Europe), we live on a ball with interlinked ocean and atmosphere. The Sun is the heater. Look, you guys have essentially all the anthropo CO2 produced in the NH but it manages to distribute itself around the globe apparently and remember humans contribute only a few percent of the CO2 flux. Given CO2 as the control knob, how do you explain a hot NH and cold SH? Or are you guys slowly letting go of the knob.
milodonharlani says: October 31, 2013 at 11:50 am
The evidence that the Medieval Warm Period was global, & that it, the Roman & Minoan WPs & the Holocene Climatic Optimum, or whatever the latest fashion in its nomenclature might be, plus the deglaciation phase prior to it, were also warmer than now has been abundant & growing since Lamb, at least, ie 50 years. The LIA & previous cold periods were also global.
Which is why Mann needed fraudulent “tricks” & apparently intentionally inept statistical techniques or lack thereof to try to show recent warming to be special & scary.
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Agreed Milodon.
We knew that Piltdown was wrong at the time his papers were published (MBH98, etc.).
I published the following article in E&E in early 2005, in defence of several legitimate climate scientists.
Full article at http://wattsupwiththat.com/2011/11/28/the-team-trying-to-get-direct-action-on-soon-and-baliunas-at-harvard/#comment-811913
Natural climate variability trumps global warming extremism.
Regards, Allan
Drive-by shootings in Kyotoville
The global warming debate heats up
Allan M.R. MacRae
[Excerpt]
But such bullying is not unique, as other researchers who challenged the scientific basis of Kyoto have learned.
Of particular sensitivity to the pro-Kyoto gang is the “hockey stick” temperature curve of 1000 to 2000 AD, as proposed by Michael Mann of University of Virginia and co-authors in Nature. Mann’s hockey stick indicates that temperatures fell only slightly from 1000 to 1900 AD, after which temperatures increased sharply as a result of humanmade increases in atmospheric CO2. Mann concluded: “Our results suggest that the latter 20th century is anomalous in the context of at least the past millennium. The 1990s was the warmest decade, and 1998 the warmest year, at moderately high levels of confidence.”
Mann’s conclusion is the cornerstone of the scientific case supporting Kyoto. However, Mann is incorrect.
Mann eliminated from the climate record both the Medieval Warm Period, a period from about 900 to 1500 AD when global temperatures were generally warmer than today, and also the Little Ice Age from about 1500 to 1800 AD, when temperatures were colder. Mann’s conclusion contradicted hundreds of previous studies on this subject, but was adopted without question by Kyoto advocates.
In the April 2003 issue of Energy and Environment, Willie Soon and Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysics and co-authors wrote a review of over 250 research papers that concluded that the Medieval Warm Period and Little Ice Age were true climatic anomalies with world-wide imprints – contradicting Mann’s hockey stick and undermining the basis of Kyoto. Soon et al were then attacked in EOS, the journal of the American Geophysical Union.
In the July 2003 issue of GSA Today, University of Ottawa geology professor Jan Veizer and Israeli astrophysicist Nir Shaviv concluded that temperatures over the past 500 million years correlate with changes in cosmic ray intensity as Earth moves in and out of the spiral arms of the Milky Way. The geologic record showed no correlation between atmospheric CO2 concentrations and temperatures, even though prehistoric CO2 levels were often many times today’s levels. Veizer and Shaviv also received “special attention” from EOS.
In both cases, the attacks were unprofessional – first, these critiques should have been launched in the journals that published the original papers, not in EOS. Also, the victims of these attacks were not given advanced notice, nor were they were given the opportunity to respond in the same issue. In both cases the victims had to wait months for their rebuttals to be published, while the specious attacks were circulated by the pro-Kyoto camp.
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thingadonta says:
October 31, 2013 at 3:43 pm
From Michael Asten in the Australian, 2010:
One of the giants of global warming science, Wally Broecker of Columbia University in New York, wrote a discussion in 2001 of evidence for the MWP being a global phenomenon, concluding tentative support for its global nature. Three years later, Phil Jones, now director of the Climate Research Unit, East Anglia, co-authored a review that concluded the MWP was a regional phenomenon. The IPCC4 report of 2007 concluded similarly; curiously, Broecker’s paper did not get a mention.
http://www.theaustralian.com.au/opinion/csiro-should-establish-if-there-was-medieval-warming-down-under/story-e6frg6zo-1225865724876#sthash.40u3Ucy4.dpuf
Article goes on to urge looking for the MWP & LIA in Australia, which would be great, but suggestive evidence of both has already been found there, however not in abundance. But the continent is bracketed by very good & plentiful studies from the Pacific & Southern Oceans (don’t know about the Indian), New Zealand, Antarctica & southern Asia.
Yeah, and one more thing. Note that the instrument watchers have all stopped tracking the arctic ice expansion just when it was rising faster than anytime in the last 60 years! Watch for an adjustment in the works after long pauses in plotting information. When they say faster warming in the last 60 years, the only warming in the last 60 years was between 1980 and 1998 – a stretch of 18 yrs, boxed in by cooling periods. Have we got annual granularity in their last 10,000 yrs? Well yes we have. The rise from early 1900s up to the forties was just as fast, and don’t forget, Hansen, Hadcrut, etc. have added on several tenths to the recent record!