Guest post by by Michael A. Lewis, Ph.D.
In my work as an archaeologist in Alaska, I spent a good swat of my time hiking through forests along the Yukon River, scrambling over piles of driftwood along the northwest coast and pulling roof beams and house posts out of 2,000 year-old dwelling sites on St. Lawrence Island.
The object of my quest? Tree rings.
From hundreds of core samples and cross-section “cookies,” I developed a regional tree ring climate chronology that I compared with archaeological records of human population movements across the Bering Strait over the past 2,500 years. One thing stood out clearly in both independent data sets:
About a thousand years ago, a remarkable change occurred among all Arctic peoples from Siberia to Greenland in a period of less than 200 years. People moved long distances. New technologies supplanted old. Ground slate harpoon blades replaced chipped stone. The sea mammal hunting Thule people of Northern Canada completely replaced the land based Dorset culture that had been in place for thousands of years. The Inuit language spread from Northwestern Alaska to Greenland, the greatest areal extent of any language on earth. Whale hunters migrated across northern Canada, following whales across the ice-free Arctic Ocean.
The tree ring record reflected these cultural changes. Across the Bering Strait and into Interior Alaska, increasing temperatures and changing precipitation patterns were recorded in tree rings from Siberia to Fort Yukon around 1,000 BP.
Something was afoot and my further research revealed the Alaskan signature of the Medieval Warming Period (MWP) that had been experienced across North America, Iceland, Greenland and Europe.
So you can imagine my surprise to see the infamous Hockey Stick graph appear in the 2001 IPCC Report, completely missing the MWP that I knew from multiple independent data sets, as well as the subsequent Little Ice Age that brought to an end the European occupation of Greenland. Later IPCC reports and subsequent media hype increased my discomfort with the concepts of Anthropogenic Global Warming and the insistence that presently observed climate change is driven primarily by human greenhouse gas emissions.
Archaeologists are “hard” scientists, driven by data, uniformitarianism, and a deep time perspective on human and natural history. My research demonstrated that humans had reacted to complex climate variation from Lake Baikal to Greenland over the past 100,000 years, climate variations that occurred in the complete absence of human greenhouse gas emissions. I see no reason to accept the automatic assumption that observed rising CO2 levels are solely the result of human emissions, or that the observed increase is significant with respect to the geological record of CO2 and temperature fluctuations.
It makes much more sense to me to view the present dynamic climatic situation in light of historical and geological records, particularly those of the past 2,000 years, for which we have independent data sets to confirm our findings. Dr. Syun-Ichi Akasofu has presented this perspective with remarkable clarity in his paper, On the recovery from the Little Ice Age, Natural Science, Vol.2, No.11, 1211-1224 (2010) http://www.scirp.org/journal/NS/
From this perspective, observed climate fluctuation is viewed as a continuation of natural geological and physical processes, in this case, recovery from the Little Ice Age.
This is not to say that human emissions do not contribute to climate fluctuation. However, we cannot understand the extent of human contributions until we fully understand the ongoing natural forces that have shaped the Earth’s climate for millennia before humans appeared on the scene.
Oh, and about smoking… in those days of yore in the wilds of Alaska, I used to smoke a pipe to wile away the lonely hours in tents and log cabins across the Arctic landscape. As my work shifted from field to laboratory, I gradually eschewed the fragrant clouds of tobacco smoke, until the day I realized I no longer enjoyed smoking.
I’m still working on the Global Warming part.
Tree ring temp graph, again! Sorry, very bad proxy for that. All tree rings show is ideal conditions for the species of tree. Temp is only a piece of that puzzle. Much better proxy for precip with temps being anywhere from above to below normal, yet still within the trees ideal range.
What’s normal? Nature surfing the sine waves of climate. One minute the ride is sweet, the next, its a body slam to the ocean floor.
But what is abnormal is the human variable that has been introduced. With 6+ billion people on the planet and the artificial changes that have been made to the landscape, and air, has this variable truly got teeth in the unfinished equation of climate we are trying to figure out? Some say yes, some no, but who will really have the last word?
Re John A says:
I guess there are other lessons to be learned wrt sustainability, centralisation and distribution. Greenland’s position always seemed precarious given cost/benefit of trading with them. One paper I read suggested the Portuguese traded there during the MWP but then stopped. With limited trade goods being produced and higher risks from changing climate, I guess that accelerated their collapse.
Other natural events have shown challenges caused by natural events, so Iceland’s volcano grounding air travel and freight and more recently the snow. Airports ran out of de-icer and couldn’t get replacements because of roads becoming blocked. Supermarkets running out of some foods because of the same problem. Lots of business lost because people typically commute further now, and couldn’t get to work so a modern society facing some of the same pressures. Don’t we ever learn from history?
Unfortunately its not enough to be a good scientist anymore. Good scientists need to protect and defend the integrity of science against the fascists like Al Gore; who seek to destroy science and truth. Remember Hitler tried to distort genetics to justify his genocide of the Jews and other races. Dont for one minute think this time is different; the only thing that will be different will be the larger scale of the crime.
“(I’m voting for swath in the first line)”
Actually, no. It’s “swat.” It’s an expression I picked up from across the pond.
Atomic Hairdryer says:
December 27, 2010 at 11:52 am
You are right!…then, it is also obvious, that only those countries running on real and trustful sources of energy will manage to survive in a cold climate scenario.
@Jeremy; Good points and what you said about this cult affirms what I think about all of this, though, thankfully, I don’t have personal experience with living within one. It’s good to read you emerged from what ever it was, but your larger point about Y2K and Climate Warming/Change/* clear.
I see it as obviously a continuation of the human to make connections and draw meaning from life and about meaning. This is as old as time itself. The climate change cult is human-based and human-centric.
And you’re right about the beer.
“Archaeologists are “hard” scientists”
“Hardly”
The hard sciences are mathematics, then physics, then chemistry; all others are applied sciences with varying degrees of “softness”.
Just a li’l nit to pick…
Enneagram says: “More scary: How sea waves could freeze in less than the blink of an eye. The following images are from Antarctica
http://www.scribd.com/doc/32858301/Frozen-Wave”
Not true. Those ice structures are formed by glaciation and then weather to create the wave-like shape. See Snopes:
http://www.snopes.com/photos/natural/antarcticwave.asp
Tony says: ” ..all those Greenland/Iceland comments reveal the sad truth that most posters do not read the posts of others.”
Yeah, rude, isn’t it? Not to mention obnoxious–having to plow past 17 comments that all say the same thing. It’s easy to do a webpage search for, say, Iceland, and see if the error has been caught below. But noooooooooooooo.
The smoking and bug repellent comment by Håkan B reminded me of the same effect I noticed while working in the Canadian Taiga in the 1970’s and 80’s.
Worst bugs of any place I’ve ever been was central Labrador. When there I wished for another ice age as they always start in central Labrador. The only days when bugs weren’t a problem were after the first frosts in September. Mid July was hellish.
http://www.snopes.com/photos/natural/antarcticwave.asp
I enjoyed and admired this post. In particular the initial graphic appealed to me, but I have one very heartfelt request for Dr Lewis. This is “Are the data that lie behind the graphic available for download? If so, would it be possible to provide an access to the unsmoothed data? ” I would be most grateful if this were so. If they are unpublished or you are going to write more papers based on them of course I would not expect you to release it! I live in hope!
Peter Miller says:
We represent Sue Grabbit & Runne, special litigation attorneys to Michael Mann and the Team.
You really represent Dewy, Cheatem and Howe, don’t you?
jorgekafkazar says:
December 27, 2010 at 1:54 pm…
jorgekafkazar, obviously, you did not read all the posts either 😉
If you had taken your own advice, you would have known that due to comments being stuck in moderation que, only Tallbloke’s first post was visible on screen while the 30-40 or so first posts were submitted.
Rude? I think not.
Best lawyer’s name of all-time? Suetching Elizabeth Yu. She “goes by” Sue. She’s an attorney in California.
the 4C age of the methane in the Siberian permafrost is 7-5 thousand years ago and about 1 thousand years ago. I can see the 5-3000 BC heat, but not much around about 1000AD.
The modern portion of the Yamal tree ring series has been discussed at length at Climate Audit.
Your tree ring graph gives me great hope.
If you run your eye along looking at the top red excursions, they dwindle toward bare little pips, until the present. Then we recover to about the same as the optimum in 5000 bc. Run your eye along the blue bottoms and you can see our slow decent into an ice age as the blues become more frequent with more “visual mass”… up until we climb out of the Little Ice Age into the present. And recover to the Modern Optimum.
I’m fairly certain that there is a strong negative feedback at about our present temperatures (as clouds carry heat to the top of the troposphere for radiation off to space). The Ice Age Glacials show there is no such limit to the downside.
Your graph gives me hope that we well might have managed to prevent our demise as the LIA headed into the Next Ice Age Glacial… and instead have managed to hold it all off, at least for a while.
To the extent there is any real AGW it looks to me like it has been a real life saver. I could learn to like that… 😉
The graph originates from Yamal larch tree ring studies.
These trees were collected on floodplains in the valleys of five local rivers cut in the tundra. The trees grow there because they find shelter against polar winters – no trees grow in the tundra . Often the rivers undermine tree roots and the trees that fell down, are covered by river alluvium and remain conserved for thousands of years.
The trees are able to grow only in June and July, peaking about 26-30th July (as calibrated using modern trees and the local meteo-station at Salekhard), and even then are some tree rings marked by hard frosts. The only growth-limiting factor differing between the years is therefore summer temperature, as water is available from the rivers.
The Shiyatov laboratory now collected tree rings 7000 years back and made chronologies of several other tree species, but their data bank is not accessible. They also don’t publish much in the international journals. Here’s the translated webpage of the laboratory:
http://tinyurl.com/34a3qub
Michael says
————–
So you can imagine my surprise to see the infamous Hockey Stick graph appear in the 2001 IPCC Report, completely missing the MWP that I knew from multiple independent data sets, as well as the subsequent Little Ice Age that brought to an end the European occupation of Greenland.
————-
Michael it’s interesting that you quote the Akasofu paper as the basis for your beliefs.
I read the paper. That paper presents many, many lines of evidence that global warming is happening.
Take home points are:
A. Mann’s hockey stick is not that different from a lot of other people’s hockey sticks, despite the missing dip in his curve which would delineate a MWP. Looks like proof the fraud allegations are all lies.
B. The tree ring data in the paper which do show the MWP also show that current temperatures match the temperatures of the MWP.
C. The Akasofu paper also extrapolates the linear trend they attribute to LIA recovery, with superimposed MDO, from which it might be inferred that temperatures are going to keep on rising well above the MWP values.
So this paper belongs to the “it is warming but it’s not our fault” species.
The irony of course is that this paper is at odds with the currently popular “it’s snowing in my backyard so that proves there is global cooling”.
“bubbagyro says:
The hard sciences are mathematics, then physics, then chemistry; all others are applied sciences with varying degrees of “softness”.”
IMO close, but not quite right. I agree with the Hard Science label and examples, but Applied Science takes the Laws of hard science, combines them with properties of matter and creates a practical application. (This is also known as Engineering). Soft Sciences are those that gather historical trend data and evidence and make postulations about their relationships, such as Archeology, Anthroplogy, etc. What makes these Soft is that the postulations, no matter how obvious, cannot be proved as absolute.
My recollection of the recent article out of Edmonton AB on expansion of the Inuit was a theory that the Arctic ocean was open enough that they could easily find food along their travel route eastward, following the coastline. (Regrets, I can’t find the article again in Canwest papers.)
The theory was put forth by researcher Robert McGhee from the Ottawa ON area, in the essay collection “The Northern World: AD 900 to 1400”.
McGhee says they had dogsleds and skin boats as travel aids.
McGhee suggested that the Inuit had heard of iron from a meteorite that people in the eastern Arctic had access to and were trading with Norsemen. McGhee suggests the Inuit were motivated to travel by economic opportunities as were the European explorers, contrary to a common view of aboriginal peoples as stay-at-home unless pushed by food supply problems or attacks.
Keith Sketchley says “Hey, they were humans – creative and interactive as usual, making use of what was available, varying with the specific society, just not nearly as far advanced in capability as the European/Mediterranean type of society fostered.”
(Trade routes existed around the world, long and arduous in olden days. For example, down eastern Africa, long distances by boat out of Mediterranean societies, overland from Manchuria, and through mountainous terrain from central B.C. to the coast near Bella Bella B.C.)
(I presume the boats were like the individual “kyak” and the much larger open “umiak”.
The lightweight boat itself would have been a major advancement, requiring figuring out structural continuity to keep the shape stable to maintain displacement volume thus flotation capacity, but with light weight to carry.)