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.
“… 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.”
How could this statement get past reviewers!?? Maybe if he said “this supports” or “is consistent with” or “argues strongly in favor”. But when did “must be the cause” start to be used in publication conclusions, other than for bench-top experiments, and then with great trepidation?
Ian W says:
October 25, 2011 at 3:44 pm
It is quite simple Svante Björck is a climate change denier.
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Ok you’re probably being sarcastic, but the term “climate change denier” is an idiotic contrivance of fools.
John from CA says:
October 25, 2011 at 3:55 pm
Ian W says:
October 25, 2011 at 3:44 pm
It is quite simple Svante Björck is a climate change denier.
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Ok you’re probably being sarcastic, but the term “climate change denier” is an idiotic contrivance of fools.
REALLY??? I believe Ian quite succinctly summed up Bjorck’s premise: “there has not been any GLOBAL climate change in 20,000 years only local” climate change denier sounds about right
[WARNING!!!! This is probably my fault since I let the original post slip through. At WUWT we do not call anyone by that term, not us, not them (whoever us and them may be). Let it stop here. -REP]
Having failed to prove global warming through tree rings, polar bear extinction, sea level rise, ocean acidification, glacier extinction, increased extreme weather events, increased drought, crop failure, disease out breaks…. they now turn to…
synchronisity?
Do they mean like say, how the NH polar ice cap is shrinking and the SH polar ice cap is growing in synchronisity? Like that?
A case of aliasing. Right through the event.
Oh, so now the Medieval Warm Period did happen, and its not being global is no longer proof that it did not happen?
Dr Michael Cejnar says:
October 25, 2011 at 3:54 pm
“… 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.”
How could this statement get past reviewers!??
My question as well. This is as ametuerish a leap of faith as could be mustered, equvalent to saying that the flying spaghetti monster was having a bad hair day. Another assertion that was physically painful to read.
“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.”
Isn’t that just another warmed-over example of “the Argument from Ignorance”?
Harvey Harrison said: “The mystery is; why is all that heat not having more of an effect?”
Because it’s irrelevant in the whole scheme of things.
Steve from Rockford
Well, we geologists are the first found examples of ethanol based life….
Harvey Harrison says:
Two things to say about that:
1. It isn’t true. Any fair reader comparing this site with most of the CAGW sites couldn’t possibly conclude anything other than that this site is amongst the most open, tolerant, and polite sites on the entire internet.
2. Anyhow, when people’s behaviour is egregious enough, it is perfectly reasonably to attack their behaviour, and this will almost inevitably be taken as an attack on them personally. Someone boasts that they’ll redefine peer review to keep out those whose research disagrees with theirs? You don’t think that indicates a serious moral deficiency that can’t be challenged by any means except to say exactly that – that such behaviour is immoral? And how can one avoid saying that without the inference being drawn that a person deliberately and without remorse doing immoral things is an immoral person?
Salting the next IPCC report? Who’s keeping track? I bet this ends up there.
Appalling lack of references to back up the claims made, agree with Craig on the points he made above.
I tossed it in the recycle bin.
“… 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 plead guilty as charged, Your Honour…
“… 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 dunno, maybe if some climate scientists spent more time in bars we’d all be better off.
He’s paid to say this, what else can you expect. It’s preparation for the next IPCC report.
I’m with Jimmy! Enjoying a “Fat Tire” while I tap this in. I’ve been wondering how long it would take before there was a concerted effort to erase the Holocene thermal excursions and even the hypsithermal. Didn’t even leave out the Younger Dryas. One wonders about the 8.2k event…..
Next up will be MIS-5e and MIS-11. Hockey. A brutal sport occasionally
Rather ironic that sceptics (of AGW) get called “deniers”. When things like this come from supporters (of AGW).
@Harvey Harrison
“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.”
Suppose the 1.7*10^16 watts of heat went into the oceans. The volume of the oceans is about 1.38^18 cubic metres http://hypertextbook.com/facts/2001/SyedQadri.shtml so human heat production would raise the temperature of the oceans at a heating rate of 1 Watt per 80 cubic metres of water which is 0.094 degrees per year, less the additional radiation into space via evaporation that probably equals this. So it could have some effect, I guess, or not.
In fact the heat goes into the air and is rapidly vented into space (probably the following evening) by slightly elevating the height of storms a few feet (for example).
If we subtract the endothermic storing of energy in biomass (which is later released when we burn it) from the total (because biomass is energy-neutral within the system) the number 1.7*10^16 is reduced. Actually I am not sure if you included biomass combustion (fields of stover, forest slash etc) in your 17 TWatts. It is usually ignored because it is burned by poor people.
It used to be thought that black carbon (BC) fell from the sky within a few km of its sources (IPCC) so its effect was ‘local’. The extra heating caused by BC from biomass is substantial and may exceed that of CO2 but that would mean CO2 has a smaller effect than has been claimed for it because total forcing is known. Thus BC influence is in a perpetual state of ‘review’ with the admitted (published) value creeping upward each year. It also shades the ground lowering the surface temperature (think, Brown Cloud of India) while raising the temperature of the lower atmosphere. Interesting, neh?
I don’t see what the problem is that some people seem to have with the conclusions of this paper.
The LACK of credible evidence for a globaly synchronous change in temperatures during the MWP, Roman or Minoan warm periods, the Holocene optimum or the Younger Dryas events is well known. As is the see-saw relationship between North and South warming/cooling episodes.
If the past climate was better defined by the proxy record it might be possible to claim with any validity that the MWP was warmer, or that the cooling during the YD event was global. It is the abscence of conclusive evidence which might be present if such events were TRUELY global that prevents any valid claim that past variations were global. While in the same way current temperature trends show a global consistancy that justifies the paper’s conclusions.
Harvey Harrison says: October 25, 2011 at 3:20 pm
This used to be an open and informative website…
Click my name and get some education. It’s not perfect but that too is education. I think it should help you evaluate WUWT better.
BTW, some warmists here claim that I don’t refer to peer-reviewed stuff. This is actually untrue, but I start off talking about certain aspects of the scientific process and my own journey. There are plenty of peer-reviewed references – just put into what I believe is the correct place, which is subservient to “Nullius In Verba”, the practice of Scientific Method at all times, towards the material in question, towards questioners, towards oneself, and towards the nature of Scientific Method itself.
My piece also puts the subject of this thread into perspective. The paper in question is indeed an affront to science but maybe done in the preparation for Durban.
Research from both hemispheres clearly shows that the MWP was a global event.
Arguing that an event is global and synchronous is like arguing that all swans are white. It only needs a single counter example (the black swan) to disprove the argument.
So for all your examples of the Younger Dryas, I offer the Antarctic Cold Reversal which precedes the Younger Dryas by well over a thousand years. http://www.climate.unibe.ch/~stocker/papers/blunier97grl.pdf
The Younger Dryas was not a global event.
Soviet-era quip: “The future is certain; only the past is subject to change.”
Robert of Ottawa says:
October 25, 2011 at 9:08 pm
He’s paid to say this, what else can you expect. It’s preparation for the next IPCC report.
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On the other hand it’s possible that he would pay good money to say it, in order to get referred to
in AR5 and ensure his place on the gravy train forever. If I hadn’t been brought up to be a cynic, the Team would have driven me to it.
As a geologist, I resent Steve from Rockwood’s insinuation. Beer review?
Far too limited in scope, especially for those of us who have spent many happy months doing fieldwork in Scotland – allows for single malt whisky review, gin and tonic review and even on occasion wine review… hic…