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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far faster? what temporal resolution did they manage to get, in the Holocene?
“” 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. “”
That means these water masses have only warmed ~0.25° C since the LIA? Does this conflict with the conclusions of Levitus et al 2012?
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.
To: Prof. Michael Mann
REF: Irony
Dear Sir,
Thank you for providing us all the ironic and incredibly pleasing spectacle of watching your nasty arrogant attitude at play as the work of your life is brought down around you.
Sincerely,
Etc.
Chalk up yet another chink in the crumbling edifice of Michael “Piltdown” Mann.
see also the editor’s comment on sciencemag.org:
Deep Heating
Global warming is popularly viewed only as an atmospheric process, when, as shown by marine temperature records covering the last several decades, most heat uptake occurs in the ocean. How did subsurface ocean temperatures vary during past warm and cold intervals? Rosenthal et al. (p. 617) present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future.
omnologos: “far faster? what temporal resolution did they manage to get, in the Holocene?”
This^. Be good to hear from someone that can go beyond the paywall and comeback with a notion of how moving the moving average is. My bet: Like all other claims, they didn’t look, don’t care, or didn’t average the modern moving average over the same range for a same comparison. Which is why we keep getting:
“The twitchy average is twitchier than the untwitchy one! We are doomed! Doomed, I say!”
lurker, passing through laughing says:
October 31, 2013 at 11:59 am
Precisely. If he keeps it up, he’s aneurism-from-cognitive-dissonance bound.
“New paper shows Medieval Warm Period was global in scope”
We need to start using words like “postulates”, or “hypothesizes” rather than “shows”. Most of these papers are “theorizing”, at best. “Suggests” is also a good word used in a previous post. It’s kind of like saying that anomalies in the rotational velocities and movements of some galaxies “show” that there is dark matter involved when they really only show that we cannot explain the velocities and movements and dark matter is “theorized” as a solution to the problem.
And latest experiments to find some have failed. Need more grant money.
Acccording to what I’ve read elsewhere, “far faster” applies to the last 60 years. That’s back to about 1950. But surface temperatures increased as fast, or almost as fast, during the first half of the 20th century.
This smells wrong.
This is not the first research paper to confirm that the Medieval Warming Period was global. Prior to Mann’s hockey stick nonsense, it was generally accepted that the MWP was global in nature by the climate science community. Even the IPCC very early on published charts to show that the MWP was global. After Mann’s hockey stick nonsense, some in the climate science community reinvestigaged the MWP and confirmed that it was global in nature. There is nothing new here… move on.
John W. Garrett said:
October 31, 2013 at 12:02 pm
Chalk up yet another chink in the crumbling edifice of Michael “Piltdown” Mann.
————————————-
“Piltdown” Mann
Good one Sir! Thanks for the LOLZ 🙂
That would mean current ocean heat content is low and the increase since the Little Ice Age is tiny.
“Michael Mann can’t be happy about this work”
Mann has been infuriated about suggestions that the MWP was global since at least 2001 when a paper was published in Science enetitled “Was the Medieval Warm Period Global?”, which basically said that it was. This is documented in at least 2 climategate emails:
http://hockeyschtick.blogspot.com/2010/01/blog-post_26.html
I just want to scream ‘what do you mean by heat?’ Ask a layman and heat means HOT. Here they are flagging 0.5-08°c, which is not HEAT. Revkin should stop pretending to be journalist.
They don’t understand that the climate is the sum of all average temperatures. Strange? Naaaa not if you know how it works. All over the world the temperature is watch t so all those temperatures to getter make one number and that s the climate where in.
So is the average temperature 16 degrees Celsius then we have the climate optimum. Whit 12 degrees its smack in the middle and whit 8 degrees its freezing cold. Now whit all the data manipulation going on where not sure were we at in this time, oke AGWers call it 14 degrees but I think where more like 11 degrees or there about. So closer to freezing than to nice warm.
The only thing is that both half’s of the world have different seasons but that wont make the sum different. Only in the sick head off someone like Mann the world works like that. In the real world it docent matter. And yes it works now it will work over 10 years and it work d 2200 years ago.
Its the same as CO2 being Capable to warm one spot and 1000 miles a way not. Stupid CO2 is as dump as the next AGWer it do sent know boundary’s. If Mann and all agwers for that mater really thinks the medieval warming was a local thing they are ready to have brain surgery. If only to look for some kind of brain or at least some thing looking like brain. A peace of hamburger from MC Donalds would do the trick.
the gooses will not believe the sun controls the heating and cooling, ps” you cannot tax the sun ” if you have time read this paper.http://www.cdejager.com/wp-content/uploads/2013/10/2013-CdeJ-HN-Sun-climate-NS-5-1112.pdf
“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.”
When looking at the _current_ global warming pattern, it looks fairly limited to Northen Hemisphere to me.
Jim G, i couldn’t agree more. The Scientismic Elites in nearly every field speak with such absolute authority, such certainty about very complex things that happened 10,000 (or 100,000 millions) years ago. The hubris is absolutely breathtaking. How long until the next study ‘shows’ something different?
The real crime is these are the people who direct and police academia, who then teach all the ‘skulls full of mush’ in the same manner. No intelligence allowed.
Maybe the climate freak-outs should start describing temperature in Kelvin rather than °C. Then 273 “degrees” would sound even more scary than it actually is. Although, I wouldn’t want to go swimming in water about the same temperature as many people did when the Titanic sank.
The oceans temps are more stable than the atmosphere, aren’t they. They find the opposite, when they compare the proxies. I think this is more evidence that the atmospheric temp proxies are missing a lot of activity.
Jquip says:
October 31, 2013 at 12:09 pm
omnologos: “far faster? what temporal resolution did they manage to get, in the Holocene?”
Heard this “far faster” term used last night while listen to Sirius/XM. They made the far faster than anytime in X million years claim along with “every day is earth day”.
As most everyone knows, I am skeptical of “paleo” studies. However, let me set aside that skepticism for a minute to explain what this paper means to Mann and his followers.
If the medieval warm period was global and reached temperatures comparable to today then natural variability can explain all warming to this time. Natural variability is the full range of our data. With regard to surface temperature data, it is the full range of data from lowest to highest value through the period of time that we can reasonably investigate.
There is no need to invoke CO2 forcing to explain a rise in temperatures from 1979 to 1998. If Mother Earth has done it before then we cannot be surprised when she does it again. There is no need to invoke any forcing as there is nothing to explain.
Of course, the fact that natural variation can account for the temperature rise does not prove that CO2 has no impact but it does put the ball in the warmest ballpark. They can no longer claim that CO2 is necessary to account for the rise. Now they must show the mechanism and the evidence for it; that is, they must solve the forcings and feedbacks equation and show that the net is positive. They have made no headway in that regard.
CO2science has a very extensive database of publications showing the global scope of the MWP:
http://www.co2science.org/data/mwp/mwpp.php
A recent one is for me key: what was a large forest doing in Patagonia 400 years ago in what is now a very large glacier: http://www.clim-past.net/8/403/2012/cp-8-403-2012.pdf (see figure 4).
jquip–
I did go beyond the paywall as you requested. Haven’t got much time to look at the results but here is Figure 3 and the Supplementary materials. A little something for every one, as they show temps higher than now throughout most of the Holocene, but also show the rate of increase much higher at present day. That was in Figure 4 of the main paper but I wasn’t able to extract that separately.
Figure 3 compares Mann to Moberg and to Oppel (2009) SST. Shows clearly how the Mann curve pushes down the Medieval period and raises up the modern, but the MOberg and Oppel agree in finding both the Medieval and the Roman periods higher than present.
Marcott 2013 also makes an appearance in the main text. Unclear whether the authors are accepting the results, but they do show them.
https://dl.dropboxusercontent.com/u/75831381/Rosenthal%20ocean%20temps%20%20Figure%203.docx
https://dl.dropboxusercontent.com/u/75831381/Rosenthal%20ocean%20temps%20Supplementary%20Materials.pdf
https://dl.dropboxusercontent.com/u/75831381/Rosenthal%20ocean%20temps%20Holocene%20Science%20Nov%201%202013.pdf