Climate Change During The Medieval Warm Period
LINK :
http://cpluhna.nau.edu/People/paleoenvironmental_change.htm
Paleoenvironmental Change
Long-term climate change causes shifts in plant, animal and human populations, but the patterns are never simple. At the end of the Pleistocene individual plant species moved independently of each other, making plant communities transitory. Human communities, when confronted with difficulties, make social and technological adjustments, giving Southwestern archaeologists reason to question whether environmental change should be given primary credit for shifts in native populations and culture. Controversy over the so-called Anasazi collapse is the primary example from this region.
What is clear is that over a long period of occupation the Anasazi did experience profound climate shifts in an already difficult environment. In the relatively benign climate of the late Holocene (700-1130 A.D.) Anasazi culture and population advanced. Water levels in streams were at a maximum, precipitation was increasing, and crop yields became more predictable. Dry farming on the mesa tops expanded dramatically, giving regional farmers roughly twice the arable land than is available today in the Four Corners area. The Anasazi became dependent on good harvests.
Historical records from 900 to 1300 A.D. in Europe indicate that this was a time of changes in atmospheric circulation known as the Medieval Warm Period. In high-latitude regions this was largely beneficial: grapes were grown in England and the Norse founded colonies first in Iceland and then in southern Greenland. But in arid regions a warmer climate, especially when accompanied by drought, can cause significant difficulties for farmers. A fifty-year drought occurred between 1130 and 1180 A.D. It was during this period that soil and water conservation features such as grid borders, terraces and check dams began to be built in the Four Corners area.
The prolonged droughts of the subsequent period must have created great stress for the Anasazi. The so-called Great Drought, a sharp decline in precipitation from 1276 to 1299 A.D., had to have been particularly devastating. The elevational zone for upland dry farming began to shrink rapidly, and may have disappeared altogether by 1300 A.D. Settlement began to aggregate in large cliff dwellings in canyons with more reliable sources of water. Food storage became paramount as did ceremonial space. But even these adaptations were short-lived; by the end of the century, Mesa Verde and other magnificent aggregations of cliff dwellings had been abandoned.
Resources:
Tags
Who is online
432 visitors
One of our members [who shall remain nameless ] published a seed featuring a video as evidence that the current south western drought is proof that AGW is the "TRUTH" . This member used a disreputable red book rule that incorporated a negative as a way to silence all disagreement . I don't do that . Judge for yourself .
There is practically no evidence that the current south-western drought is caused by CO2 or AGW . The mere fact that such extensive droughts have happened there in the past puts any such assumptions in doubt .
Was there any AGW going on during the Medieval Warm Period ? Of course not . What evidence is there to conclude that the current drought is different than what happened in history ? Would anyone care to answer that ?
There is on more factor to mention . Dr. Michael Mann published the famous hockey stick graph to prove that gobal warming is getting drastic . But to make the graph convincing he needed to remove evidence of the Medieval Warm Period . So he cherry picked his data by using a faulty data set for that express purpose . This scoundrel should not be in charge of a university program . He should be brought up on charges ...
As I understand the Anasazi story, the "disappearance" is a Navajo story. The Navajo arrived in the area, found empty cliff-towns, and invented a "legend" to explain it all.
The Hopi, on the other hand, consider themselves to be the direct descendants of the Anasazi. The Anasazi never "disappeared" at all.
(And as far as I can tell, this has nothing to do with AGW.)
No Red Book rules? Great! Then I can put this up!
Hubert Lamb
Your personal comments aside, I do not really understand what is meant by " individual plant species moved independently of each other, making plant communities transitory." As climates change, some plants die, and others thrive-- that makes sense. But I've never known a plant that can pick itself up and move... I'm sure that's not what you meant. Can you explain this part further?
Secondly, here are some of the links from the University of Kentucky's web site-- the reason I'm linking them is below:
Climate Change-- A Brief Summary of Extension Agents
Confronting Global Warming
Forum -- Climate Change: Values, National Security, and Free Enterprise
Climate Change Warming Kentucky and Indiana
Most Farmers See Climate Change But Can't See Human Activities Causing It
Soils Limited in Storing CO2 and Mitigating Climate Change
The reason for linking these articles is this: a quick search, parameters University of Kentucky global warming, yielded these articles, discussions, and forums from UK. This wasn't a specialized search. However, among scientists, and I have met these fellows and spoken with several of them through my position on the Board, there is a universal consensus that global warming is real. At present, carbon sequestration is the big area for research . No one doubts that global warming is occurring.
My purpose of the Red Box Rules, were this: I'm not going to debate whether or not global warming is occurring when the scientific community believes it is. The article was based on the premise that global warming is occurring-- for whatever reason. That was the sole assumption.
If you don't want to believe it, for whatever reason-- don't. Frankly, my dear, I don't give a damn.
The precise historical details are unimportant . What is well known is that there was a very lengthy & severe drought in that region .
The fact that there have been severe droughts in that same region in the distant past [before any possible AGW influence] implies further evidence is needed . Explaining how the current drought requires AGW as support when such events have happened naturally in the past without AGW is a big hurdle to overcome for the big dogs of climatology like Michael Mann .
That was part of the article but I would guess the author was talking about the difficulties faced by an agricultural society in the face of a severe drought .
That is a gross exaggeration . Claiming that there are NO scientists who disagree with the AGW hypothesis is just propagandizing . If I posted a link to a meta research article that lists dozens of them would you even read it ... or would you just accept the blanket statement pushed by the alarmist media on this topic ? I suspect the latter .
Translation : You refuse to even look at evidence that disagrees with your already set beliefs . Are you going to accept my challenge and examine a link if I post it ? If not I will have permanently lost respect for your tactics and mind set .
As to your red box rules , it's fine to establish some but to not follow your own rules is a travesty . You said not to present evidence supporting AGW denial . But I merely attacked the premise of the video you posted . To seed something & then disallow dispute on the evidence you present could only be called censorship , censorship of the worst kind , designed to create an echo chamber of agreement .
Anyone who squashes debate on a topic is not interested in debate , only squashing . You stepped all over the complex point I was attempting to make on a forum full of the uninformed . You need to hold yourself responsible for perpetuating their ignorance .
You believe in the AGW theory but refuse to even hear disagreement shows a closed minded attitude.I would be ashamed to demonstrate such an attitude on a public forum . You will now have to live with the consequences of your attitude because it's out there for all the readers to see . As to your pictorial meme , it shows a lack of maturity & seriousness . If you can't even come up with an argument but instead a childish tantrum you are acting like an infant , not a grown woman ... or is that the model you have in your mind for a grown woman ? If it is a shared vision the country is doomed .
Petey, you're coming very close to having a CoC violation-- especially IF you posted this article only rake me over the coals for having an article with Red Box Rules. You don't like them? Then don't comment on them.
Your opinion is yours, and I feel sure there are many that agree and/or disagree with you. The purpose of Red Box Rules, is to set parameters for discussion. One of my parameters was that GW is established science, and not in dispute. You certainly did not have to participate. And you have published an article that disputes that. Good for you! Yeeehaaa!
I have been reading about GW since the late 70s-- and I certainly remember that when we had the blizzard of '77 and then one in '78, scientists were all over the news talking about a new ice age. I wish I could find the articles in the TPG, (The Professional Geologist), that discussed GW as a part of a natural cycle, and those following articles debunking the theory. They were published in the early 1980s. Unfortunately, they are not archived on line.
I believe that you are looking at this from a political standpoint, not necessarily from a scientific viewpoint. Which is fine! Go for it! However, I am not wasting another moment of my time discussing this with you.
That may be but that is beside the point . The issue is whether or not AGW is happening . Is warming being caused by human intervention or not ? Is it due to the undisputed rise in CO2 levels or due to another factor , for example soot ? We are talking at cross purposes until you stop misinterpreting my position .
OK . Then it should be easy to dispute what I said with science . What you believe I am doing is not necessarily accurate . From my POV your position as a worshipper at the throne of AGW is unsupported by real evidence .
If this is what you call discussion you are unclear on the concept .
Well ! We agree more or less on that point .
Oops ... too late . You already had your tantrum and your drama . It's right there in your previous comment for all to see . And that meme ? It describes exactly what you are doing , queenie .
Petey, I believe much like Feronia does.
It seems that this is, from your introduction to the article, nothing but a hit piece on another member.
Put on your big boy pants, and quit whining. If your don't like Dowser's article, don't read it. To drag her into it is really child like.
Are you sure you're talking about the article & not one of my comments ? The article stands on it's own . Feel free to comment ON THE ARTICLE . As far as Dowser goes , that is between her & myself . It is not your concern . So get on topic ... the article . It is strong evidence against AGW . Feel free to counter it if you can .
Wrong. It is not between you and Dowser. It is about the tone of the front page. You could have posted your own article if you felt that you didn't like the format of Dowser's article but you should be making less than vague comments about why you are posting your article. It then becomes not just an article but also a slap in the face. I would have removed the comment, if I saw it earlier, then it would have been a case of no harm no foul, but since the cat is out of the bag, this better not happen again.
Are you willing to accept objections to faulty use of red book rules ? Are you available to appeal about improper comment deletions done under RBRs ? If you want to discuss this issue let's do it in private , not on my seed .
This is a serious seed on the topic of AGW . It is not a hit piece as was claimed above . The FP is unaffected by the presence of my article . NO MEMBER WAS MENTIONED BY NAME in that comment . I stand by this seed as a valid argument against the AGW hypothesis . Do you disagree ?
Since I didn't read Dowser's RBR article, I can't tell you if there is a faulty use of the RBR's But the bottom line to the use of the RBR's is that the author makes the call and then the comment is removed. If you feel that an article or an author has RBR's that are not to your liking, then please don't participate. Your article is fine in content, but your first comment was the issue and it resides on this article and hence why I commented here.We can talk about this more in private and this will be the last meta comment here from me, unless you decide to continue it here.
From what you said I gather there is no appeals process for RBRs . If that is the case I will be more careful in participating on such articles in the future .
Thanks for your clarifying comment .
I expect that is about Arctic sea ice melt ... right ? That would not be a year round factor since the sea ice regrows every winter .
Very good comment Feronia.
Now back to round two! LOL
I thought it was the Arctic. See there, I don't know what I'm talking about.
Seriously, I really wonder about the deforestation and think it is terrible as much I have read. You know you can read something, but that doesn't make it true, but here is something interesting.....
How Much Oxygen Does One Tree Produce?
Question: How Much Oxygen Does One Tree Produce?
Even a single tree can produce enough oxygen to support several people. Martin Ruegner, Getty Images
You've probably heard that trees produce oxygen, but have you ever wondered just how much oxygen one tree makes? The amount of oxygen produced by a tree depends on several factors, but here are some typical calculations.
Answer: The atmosphere of the Earth has a different composition from that of other planets in part due to the biochemical reactions of Earth's organisms. Trees and plankton play a big role in this. You've probably heard that trees produce oxygen, but have you ever wondered how much oxygen that is? You'll hear a range of numbers and ways of presenting them because the amount of oxygen produced by a tree depends on the species of tree, its age, its health, and also on the tree's surroundings. According to the Arbor Day Foundation, "a mature leafy tree produces as much oxygen in a season as 10 people inhale in a year." Here are some other quoted figures regarding the amount of oxygen produced by a tree:
"A single mature tree can absorb carbon dioxide at a rate of 48 lbs./year and release enough oxygen back into the atmosphere to support 2 human beings."
- McAliney, Mike. Arguments for Land Conservation: Documentation and Information Sources for Land Resources Protection, Trust for Public Land, Sacramento, CA, December, 1993
"One acre of trees annually consumes the amount of carbon dioxide equivalent to that produced by driving an average car for 26,000 miles. That same acre of trees also produces enough oxygen for 18 people to breathe for a year."
- New York Times
" A 100-ft tree, 18" diameter at its base, produces 6,000 pounds of oxygen."
- Northwest Territories Forest Management
"On average, one tree produces nearly 260 pounds of oxygen each year. Two mature trees can provide enough oxygen for a family of four."
- Environment Canada, Canada's national environmental agency
"Mean net annual oxygen production (after accounting for decomposition) per hectare of trees (100% tree canopy) offsets oxygen consumption of 19 people per year (eight people per acre of tree cover), but ranges from nine people per hectare of canopy cover (four people/ac cover) in Minneapolis, Minnesota, to 28 people/ha cover (12 people/ac cover) in Calgary, Alberta."
- U.S. Forest Service and International Society of Arboriculture joint publication
~Link~
Something to think about.
Every 1520 years, Mother Earth changes her clothes and rearranges the furniture.
BTW Petey, travel 'bout 1,200 miles to the South and you read of the 600 year drought that eliminated millions of people in 'bout 300 AD.
Thanks 1st . Was that in South America ?
Trees help a lot . The one thing that is most unappreciated is the the influence of plankton on CO2 absorption and O2 creation ...