Guest post by Dr. Don J. Easterbrook
Dept. of Geology, Western Washington University, Bellingham, WA
In a paper entitled “Current global warming appears anomalous in relation to the climate of the last 20 000 years,” Svante Björck claims that, over the past 20,000 years, there have been no world-wide, synchronous, climate changes until recently and that shows CO2 must be the cause of recent global warming. He claims that:
It is, however, virtually impossible to find evidence for globally synchronous climate events with the same climate signature, for example warmings or coolings.” “When the last ca. 20 000 yr of climate development is reviewed, including the climatically dramatic period when the Last Ice Age ended, the Last Termination, it appears that the last centuries of globally rising temperatures should be regarded as an anomaly.”
“…..no globally consistent climate event prior to today’s global warming has been clearly documented” so ….“we ought to regard the ongoing changes as anomalies, triggered by anthropogenically forced alterations of the carbon cycle.”
This apparent return to the ‘hockey stick’ argument includes denials of the global Roman warm period, the Dark ages cold period, the Medieval Warm Period, and the Little Ice Age.
“The often-cited climate pattern of the last 2000 to 3000 yr with the Roman Warm Period, the Dark Cold ages, the Medieval Warm Period and the Little Ice Age (LIA) seems to be restricted to the NH or parts of it, and does not show up as a global pattern of warmings and coolings. it is important to note that while the LIA was not a period of global cooling.”
Claims such as these can only be considered geofantasy, unsupported by scientific data and contrary to a vast amount of data to the contrary. For example, Björck claims that the large swings in temperature at the end of the last Ice Age, especially during the Younger Dryas (YD), were not global despite many peer-reviewed papers (when peer review meant something) documenting the global extent of the YD. The magnitude and intensity of late Pleistocene climate changes were much, much greater than recent warming and cooling (Fig.1).
Figure 1. Greenland ice core data showing abrupt warming and cooling events during the past 25,000 years. As shown by corresponding expansion and contraction of glaciers worldwide, these were globally synchronous events.
The Greenland isotope ice core data is well correlated with glacier advance and retreat in the European Alps, Scotland, Sweden, Norway, Finland, Russia, the Rocky Mts., the Cascade Mts., Sierra Nevada, Argentina, Chile, New Zealand, and various other places. The global record of non-glaciated areas is also clear in Asia, Australia, New Zealand,, North and South America, Europe, Russia, and elsewhere. There is a vast literature documenting all of these globally synchronous climate changes that Björck obviously needs to read.
The Younger Dryas abrupt and intense climate changes are not only globally synchronous, but are in fact practically simultaneous in both the Northern and Southern Hemisphere (see for example, Easterbrook 2011, Evidence for synchronous global climatic events: cosmogenic exposure ages of Pleistocene alpine glaciations, Elsevier). Figure 2, shows that not only is the Younger Dryas globally synchronous, but that advances within the YD can also be correlated globally, including examples from continental ice sheets in Scandinavia and North America, and alpine glaciers in the Cascade and Rocky Mts. of North America, the European Alps, and the New Zealand Alps, among many others.
Figure 2. Global correlation of phases within the Younger Dryas.
Globally synchronous Little Ice Age glacial advances and retreats are also well documented in the geologic literature, as well as the Medieval Warm Period. Well-defined glacial moraines lie downvalley from almost every glacier in the world!
How Björck can ignore this immense amount of data showing globally synchronous climate changes is very difficult to understand. His claim of no globally synchronous climate changes in 20,000 cannot be considered credible.
“when peer review meant something”
Had to laugh at that one. I predict our planet will ultimately be saved by geologists, who are perhaps the only group of scientists who can understand time on the same scale as the earth understands it. Assuming we can pull them out of the bars. Beer review. That’s all they understand.
I posted these on Steve’s the other day……
http://www.clim-past-discuss.net/7/3131/2011/cpd-7-3131-2011.pdf
That’s a discussion on glaciers in Chile….. and then there’s this…..
http://pages.science-skeptical.de/MWP/MedievalWarmPeriod.html
Sigh……
I believe that both Bjorck and Easterbrook are overlooking some evidence. Interesting enough it was the same Bjorck, who discovered that the Younger Dryas summers were anomalous warm in Greenland. http://geology.gsapubs.org/content/30/5/427.abstract
The same is noted for instance by Lucke and Brauer 2004* from the pollen in the meerfelder maar. Furthermore I’d be very interested to see unambigous evidence of advancing glaciers, correctly (!) dated within the Younger Dryas. As far as I know this is only shown for the Loch Lomond glacier advances in Scotland.
There are many more fishy things about the Younger Dryas, in general it looks to me that the Younger Dryas was not that cold but bone dry in many parts of the world, but not all.
I think indeed that the last glacial transition was more or less synchronous, however the isotope patterns in the Antarctic and Greenland ice cores (incorrectly assumed to represent paleo temperature do not support that.
Plenty more where this is coming from.
Andre
*Lücke, A. Brauer A., 2004. Biogeochemical and micro-facial fingerprints of ecosystem response to
rapid Late Glacial climatic changes in varved sediments of Meerfelder Maar (Germany).
Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 211, Issues 1- 2, 19 August.
I can locate several papers right this minute that show LIA impact in the Southern Hemisphere. Anyone having access to an academic library would, too. In fact, simply peruse the index of the last few years of Quaternary Research (four issues per volume, not too may issues to peruse).
Lazy research, in my opinion.
Somewhere recently, a geologist remarked that at the time of his commenting, there had been 1900 papers published on The Little Ice Age and Medieval Warm period and other recent fluctuations.
Just tell Bjorck he is dreaming. Maybe it is a last surge at the IPCC trough.
It is breathtaking to witness lifelong scientists prostitute themselves for an agenda.
Well one thing that happens synchronously as you go back is that climate error bars get larger and larger.
In this study, they compare a single southern hemisphere site to the Bond et al. 2001 Ice Rafted Debris history. That raises a red flag right there–1 site vs 1 site. There is NO reason to believe that a single site will track global changes. A shift in prevailing currents or winds could make a locality not track the global trends over this time span. Both data sets have dating difficulties as all sediment studies do. The original data is in a 2007 paper and is almost not described at all in this paper. The description of the implications of the figure are totally casual. The ability to detect and compare oscillations depends critically on the sampling density (not described) and the number of dating control points (not described). Measurement error and confounding factors could also reduce the appearance of synchrony between the two data sets. For example, lab error can be greater than the signal one wishes to detect. One almost never can just plot up 2 such graphs and make any sense of it per se. This is appalling. Most of the paper is a qualitative comparison of N and S hemisphere histories, again much too casually done, with no mention of dating error/issues or sampling/lab errors or data source reliability.
It’s science as advertising–based on the principle that if something, however ill-founded, is said often enough, people start to believe it. And the general public are busy, or lazy, and don’t have time/skills to burrow into the data to evaluate the statements–and the specialists who do are not communicating effectively with the public. Except for blogs like yours of course and thank heaven for that. Really enjoy reading it. Keep it up!
“It is, however, virtually impossible to find evidence for globally synchronous climate events with the same climate signature, for example warmings or coolings.”
Are we having synchronous global warming now? I thought 33% of the temperature stations were reporting declines?
The scale in Figure 1 seems wrong:– all temperatures are well below freezing?
Also, the base line (at -32 degrees Centigrade) could be anywhere.
+32 degrees Fahrenheit is freezing — perhaps the scale should be in F and translated?
Svante Björck’s paper is peer reviewed and open access. I’d encourage everyone to read it and post their critical comments here.
Just looking at the abstract, his logic is that since the past climate changes were so globally heterogeneous, the present globally uniform change should be considered anthropogenic. This is specious science in any case, because he’s arguing causality by induction.
It’s also true that the resolution of past climate change is very poor compared to present instrumental records, and so we can’t know whether there were climate swings in the past equivalent to the small changes we see today..
Björck makes hay out of this poor resolution of past climate by saying that since we don’t know that the past had similar changes, we should conclude that the changes today are anthropogenic.
And, of course, part of the reason climate change today seems so globally uniform is because all the local heterogeneity is removed by averaging.
crosspatch says:
October 25, 2011 at 2:39 pm
I can locate several papers right this minute that show LIA impact in the Southern Hemisphere. Anyone having access to an academic library would, too. In fact, simply peruse the index of the last few years of Quaternary Research (four issues per volume, not too may issues to peruse).
Lazy research, in my opinion.
============================================
I think you’re being a bit too charitable. He presented what he presented because that is the perspective he supports.
This used to be an open and informative website but recently has devolved into personal attacks on the people at the centre of the ‘Climategate’ controversy. Granted there is a lot not to like about the IPCC but they are no different than any other ‘Old Boys Club’.
Read your own banner Anthony ‘Commentary on the puzzling things in life…’, and that includes other things than the climate.
The human race is heading for a crisis, or perhaps many, that will result in one or more ‘Gigadeath’ events that might well kill off what we call ‘civilization’. The future will be one of walled continents, then walled countries and finally a devolution to walled cities as the population implodes and all that we call ‘human’ dies; unless we change the future.
Focus on ways to avoid the first Gigadeath event or it will grease the slippery slope to barbarism. My personal attitude is that ‘Anything sufficiently procrastinated can be avoided entirely’ so how do we gain enough time to avoid Gigadeath?
Rather than argue about the indirect effects humans might have on the planet via CO2 take direct action on direct effects. Prime amongst these is gross heat output. We humans produce somewhere in the neighbourhood of 17 terawatts of heat continuously (85% from fossil fuels) and all that heat must be having some effect.
With difficulty the gaseous and particulate by-products of burning fossil fuels can be cleaned up and clean nuclear developed but that does nothing about the gross heat.
The mystery is; why is all that heat not having more of an effect?
It seems to me that the BESt study just showed that the warming of the last 200 year hasn’t been global either. Didn’t the y show that roughly 30% of the stations had actually cooled slightly.
What I love is claims that a mountain of data is not ‘global’ because it does not cover ever square inch, but a hand full of ‘magic trees’ from one area can be used to prove a ‘global’ situation . Guess that’s why there magic along with the way they can be misused to support the ‘Stick ‘
If something, anything really, “appears to be” like the alarmist-mongers are right then it “seems to be” only fair that “we ought to” do whatever crazy acts of economical perversion they demand. Because, (just think of the potential future children), what if they really are right. And all they really want is just free access to all our money (all you’re money are belong to us), which would mean nobody, except them, would afford our current way of life and how bad could that be (think of the potential future children again.)
A mentally healthy scientists answers, (on the question if he has all his faculties together,) I think so.
A CAGW (pseudo)scientists answers: Well, of course you little heretic, to believe anything else could in my definition possibly be complete lunacy. This here [INSERT “SCIENTIST’S” OWN NAME] thinks it might just be crazy to think otherwise!
:p
I’ll bet ten Quatloos that the real purpose behind Svante Björck’s paper was to get the above statement into the peer reviewed literature before the cut off date for AR5. If past is present, they will include his paper and ignore the rest thus resurrecting the ‘Hockey Stick’ temperature graph as gospel.
This is the very definition of insanity. A delusion so intense that reality becomes irrelevant.
If anyone doubted climate scientists were for sale …
Isn’t the procession of the equinoxes about 25,000 years so Norther summer/winter and the Perihelion/Aphelion swap about every 13,000 years?
Given the difference in ocean/land ratios in the Northern/Southern hemispheres; no effect would mean physics is wrong.
Knowing Björck’s Mannian agenda, should he:
a) Admit that he didn’t use sufficient proxies, or
b) Sell his soul
Dr. Easterbrook are you pulling an Anthony puzzle game on us?
Globally synchronous is a contradiction in terms. Science at all levels freely admits they don’t fully understand the climate system so the idea of a synchronous system based on lack of understanding simply becomes generalizations and sooth saying.
None of the data supports anything globally synchronous, its actually physically impossible if one looks at the global at any single point in time.
Even during Ice age events, nothing, even poorly understood, appears to be globally synchronous.
It is quite simple Svante Björck is a climate change denier.
Björck seems to have deliberately ignored all the evidence of large swings in global temperatures:
http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Ice-core-isotope.png/800px-Ice-core-isotope.png
Synchronous temperature variations in both hemispheres:
http://wattsupwiththat.files.wordpress.com/2011/02/3cores.png
Ample evidence falsifies Björck’s claim:
http://www.gisp2.sr.unh.edu/IMAGESGISP2/Bender-NSF.GIF
Not only did global temperatures change drastically, but CO2 rises always followed temperature rises:
http://www.brighton73.freeserve.co.uk/gw/paleo/400000yearslarge.gif
More evidence of large temperature changes over the past 20,000 years:
http://i90.photobucket.com/albums/k247/dhm1353/Climate%20Change/GISP2_50kya.png