We’ve always suspected this for some time, as the MWP ended, they became isolated by the change in weather patterns as the climate turned colder. Nice to see it in a peer reviewed publication finally.
From Wiley-Blackwell
Did climate change cause Greenland’s ancient Viking community to collapse?
Our changing climate usually appears to be a very modern problem, yet new research from Greenland published in Boreas, suggests that the AD 1350 collapse of a centuries old colony established by Viking settlers may have been caused by declining temperatures and a rise in sea-ice. The authors suggest the collapse of the Greenland Norse presents a historical example of a society which failed to adapt to climate change.
The research, led by Dr Sofia Ribeiro from the University of Copenhagen, currently at the Geological Survey of Denmark and Greenland, focused on Disko Bay in Western Greenland and used a marine sediment record to reconstruct climate change over the last 1500 years.
Events which occurred during this time frame included the arrival of Norse settlers, led by Eric the Red in AD 985. After establishing a colony known as the Western Settlement the Norse traveled north to Disko Bay, a prime hunting ground for walruses and seals.
“Our study indicates that at the time the Norse arrived in West Greenland, climate conditions were relatively mild and were favorable to the settlers” said Ribeiro. “However, in AD 1350 the settlement collapsed, the cause of which has long been debated.”
The marine perspective of the research is especially relevant as the Norse inhabited inner fjord areas. The team’s research compared robust air temperature reconstructions based on ice-core data with their own marine record. The results underline the regional complexity of climate patterns in the study area, which may vary from ice core reconstructions, and are strongly controlled by the fluctuating influence of “warm” Atlantic waters entrained by the West Greenland Current.
“Our study shows a major shift towards cooler conditions and extensive sea-ice which coincides with the estimated time for the collapse of the Western Settlement in AD 1350,” said Dr Ribeiro. “The Norse were proud of being Europeans, farmers and Christians, and never adopted the hunting and survival techniques of the Inuit, so these temperature shifts would have caused significant problems for the colonists and their livestock.”
Agricultural difficulties are believed to have forced the Norse to rely on marine resources, yet the increase in sea-ice, the team suggests, would have had a major impact on species such as migratory seals, while blocking trade routes.
“We cannot attribute the end of the Norse civilisation to a single factor, but there is enough evidence to suggest that climate change played a major role in determining its collapse,” concluded Ribeiro. “Harsh climate conditions made farming and cattle production increasingly difficult and the extensive sea-ice prevented navigation and trading with Europe.”
“There is perhaps an important lesson to learn from the Norse collapse and that is a lesson of adaptation, of being able to adjust our values and life-style when times change. That is an important challenge we face today as a society.”
Climate variability in West Greenland during the past 1500 years: evidence from a high-resolution marine palynological record from Disko Bay
Ribeiro, S., Moros, M., Ellegaard, M. & Kuijpers, A. 2011: Climate variability in West Greenland during the past 1500 years: evidence from a high-resolution marine palynological record from Disko Bay. Boreas, 10.1111/j.1502-3885.2011.00216.x. ISSN 0300-9483.
Here we document late-Holocene climate variability in West Greenland as inferred from a marine sediment record from the outer Disko Bay. Organic-walled dinoflagellate cysts and other palynomorphs were used to reconstruct environmental changes in the area through the last c. 1500 years at 30–40 years resolution. Sea ice cover and primary productivity were identified as the two main factors driving dinoflagellate cyst community changes through time. Our data provide evidence for an opposite climate trend in West Greenland relative to the NE Atlantic region from c. AD 500 to 1050. For the same period, sea-surface temperatures in Disko Bay are out-of-phase with Greenland ice-core reconstructed temperatures and marine proxy data from South and East Greenland. This is probably governed by an NAO-type pattern, which results in warmer sea-surface conditions with less extensive sea ice in the area for the later part of the Dark Ages cold period (c. AD 500 to 750) and cooler conditions with extensive sea ice inferred for the first part of the Medieval Climate Anomaly (MCA) (c. AD 750 to 1050). After c. AD 1050, the marine climate in Disko Bay becomes in-phase with trends described for the NE Atlantic, reflected in the warmer interval for the remainder of the MCA (c. AD 1050–1250), followed by cooling towards the onset of the Little Ice Age at c. AD 1400. The inferred scenario of climate deterioration and extensive sea ice is concomitant with the collapse of the Norse Western Settlement in Greenland at c. AD 1350.
===============================================================
Supporting info:
Table S1: Raw counts of charcoal, foraminiferal linings, dinoflagellate cyst taxa, and other palynomorphs from the Disco Bay sediment core.
Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article.
| Filename | Format | Size | Description |
|---|---|---|---|
| BOR_216_sm_supplinfo-s1.pdf |
Yo, noob, you’re moving the goal posts again. I said the trend is the same. Try to stay on point. And the slowly rising temperatures from the LIA are not evidence of CO2 emissions. Unless you have, like, evidence that CO2 is the cause. As if.
Does anyone else find it odd…that on a thread talking about the demise of an entire society…because of their failure to adapt to climate change….
Someone is arguing that life would just be perfect if CO2 levels were exactly like they were then………..
Smokey says @ur momisugly June 21, 2011 at 6:17 pm “I said the trend is the same.”
OK – so all you are claiming then is that you have a chart where the hand-added line trend line also points up, albeit from a much higher starting point and to a much higher temperature. That is the extent of your claim? That doesn’t seem like much evidence of anything other than change – certainly not enough to prove or refute anything.
It’s been warmer. It’s been cooler. How does that negate any of the science that shows that excessive CO2 from our activities is cause changes in the earth atmosphere?
Latitude says @ur momisugly June 21, 2011 at 6:34 pm “Does anyone else find it odd…that on a thread talking about the demise of an entire society…because of their failure to adapt to climate change….”
No, but I am sure some people here find it deeply ironic that you are suggesting climate change can have that big of an impact while many here argue the warming we are seeing is of no concern….
MR,
You are still floundering around trying to prove somehow that CO2 causes rising temperatures. But you have zero empirical, testable, measurable evidence to support that claim. You only reject Phil Jones’ chart because it disconfirms your belief system.
Unless you can provide observed, measurable, testable evidence, per the scientific method, to support your belief in the magical juju of a tiny trace gas, you belong on the RealClimatePropagandaCensoring blog, not here at the internet’s Best Science site – where we demand verifiable facts and evidence, not true belief. So far, you have provided no such evidence. But don’t feel bad, no one else has, either.
Smokey says @ur momisugly June 21, 2011 at 7:16 pm ” You only reject Phil Jones’ chart because it disconfirms your belief system. ”
I’m not “disconfirming” the chart – just the assertion you are making from it.
Smokey says @ur momisugly June 21, 2011 at 7:16 pm ” You are still floundering around trying to prove somehow that CO2 causes rising temperatures. But you have zero empirical, testable, measurable evidence to support that claim. ”
Back to arguing with physics eh? Are you quite sure you want to state for the record that CO2 cannot cause warming?
MR says:
“Are you quite sure you want to state for the record that CO2 cannot cause warming?”
Absolutely. CO2 only acts like a blanket; it delays loss of energy to space. It does not cause warming, as MR mistakenly believes. ModRep really needs to get up to speed on this topic.
If CO2 caused warming, a flask of CO2 would be a wonderful hot water bottle that would cause endless heat to be emitted – like a fantastic perpetual motion machine.
Moderate Republican says:
June 20, 2011 at 4:54 pm
OK…and what exactly? It’s been warmer. It’s been cooler. How does that negate any of the science that shows that excessive CO2 from our activities is cause changes in the earth atmosphere?
The problem is that the only real evidence for CO2 induced warming of the magnitude generally claimed is from interpreting the historical temperature record and attributing changes to natural and human factors.
Other evidence is weak to non-existent.
Crucially, direct measurement of outgoing longwave radiation does not show significant decrease in the CO2 absorption bands. The only decreases are seen in the methane and ozone absorption bands.
The increase in ozone OLR absorption is rather ironic, because billions have been spent trying to increase ozone levels.
Even more ironic is that Montreal protocol touted as a great success and a model for international cooperation in managing atmospheric ozone levels, looks to be a bigger contributor to global warming than all human CO2 emissions.
Finally, whether or not increasing CO2 affects the climate is a strawman argument. There will be some effect, the question is how large.
MR. your use of non-standard English is disconcerting and also obscures any point you are attempting to make. Many posters here on WUWT have English as a second or third language and they make their points clearly and without ambiguity.
Please try again.
Here you go Smokey:
Laboratory tests show carbon dioxide absorbs longwave radiation. Satellite measurements confirm less longwave radiation is escaping to space at carbon dioxide absorptive wavelengths. Surface measurements find more longwave radiation returning back to Earth at these same wavelengths. The result of this energy imbalance is the accumulation of heat over the last 40 years.
Here you go SteveE:
click1
click2
click3
The effect of CO2 is so insignificant that it is overwhelmed by other factors. I would be surprised if the sensitivity to 2xCO2 is even 0.5°C. Despite all the arm-waving, the effect of CO2 is so minuscule that it just doesn’t matter in the big picture. It is a non-problem.
And increased CO2 is not only completely harmless, it is a net benefit to the biosphere. Charts on request.☺
Reader,
From what I recall, the historians’ consensus …o, how that word has been irredeemably ruined… was that the Scandinavians and the Inu rarely had contact with one another and most likely fought sporadically. I do recall a DNA study of the Greenlanders, but it was about how the Vikings’ DNA showed Celtic input, probably from their earlier contacts with people in the northern British isles.
As for Nansen’s “race consciousness was not an issue,” I have trouble believing that, along with similar Noble Savage bubemeise. Humans are naturally naughty as well as delightful, on the rare occasion, and this “racial awareness” thing is an omnipresent universal stain and as natural as our other little foibles such as an appetite for astounding cruelty and wanton destruction. Our seemingly hard-wired preference for people who look, speak, live, think and behave like us is what is “normal”; it is our better qualities, such as tolerance and genuine acceptance of differences which have to be developed and nurtured. Furthermore, it is only modern Western society that has made genuine, deep, structural and systematic attempts to resist our deeply entrenched and natural chauvinism, and while there are still serious problems, we have come further than any civilization in history. In this and in other cases, we may take justified pride in resisting “Mother Nature.”
The research on the story of the Greenlanders is still ongoing, but I’ll wager that little or no evidence of Inu genes will appear in Scandinavian remains buried at the settlement cemeteries. Among both the descendants of the Vikings and the Inu “racial consciousness,” as this late 19th century term is to be understood (i.e., limited to superficial physiological differences) , may have played a minor role, but language and cultural differences undoubtedly presented an unfathomable gulf.
But all this stuff aside, the idea that apart from a few individuals, the Greenlander communities could have survived intact by learning from the Arctic peoples, even if they could cross the cultural divide is sheer fantasy; the Inu technology and methods were geared for a nomadic, hunter-gatherer existence, something the community of settled agrarian Scandinavians would not have been able to adapt to in time, even if so inclined.
“Many posters here on WUWT have English as a second or third language and they make their points clearly and without ambiguity.” (Alexander K to Moderate Republican)
Me, I strained my brain, such as it is, through three other languages, but I speak English the bestest.
Smokey, Those graphs show nothing to back up your claim that CO2 doesn’t cause global warming, the second one in particular shows nothing at all other than cherry picking from ~1998 to 2011 shows a negative gradient for some place on this planet…
You’re really going to have to try harder than that to refute the satellite measurements that show infrared spectra over the past 40 years observe less energy escaping to space at the wavelengths associated with CO2 and surface measurements find more downward infrared radiation warming the planet’s surface. This provides a direct, empirical causal link between CO2 and global warming.
SteveE,
There is nothing incorrect about my statement above: “The effect of CO2 is so insignificant that it is overwhelmed by other factors.” Empirical observations bear this out. As CO2 steadily increases, global temperatures are flat to declining, and the steric sea level rise due to thermal expansion is falling rapidly.
You’re going to really have to try harder to provide empirical, testable measurements showing that CO2 causes global harm. So far, there is no such evidence. There are only models and conjecture, which planet earth is falsifying.
Any effect from anthropogenic CO2 is down in the noise, and is too small to be measured. That is why there is this endless argument. Because if the effect from CO2 was large enough to measure, the argument would be settled.
@Smokey
> Absolutely. CO2 only acts like a blanket; it delays loss of energy to space.
> It does not cause warming, …
Not quite right my friend. Since it does act like a blanket, it can cause warming by slowing down the escape of heat into space from surface objects re-radiating absorbed solar radiation and such. Just like the insulation on your house keeps it warmer inside by slowing down the escape of heat through the walls. The insulation in your house does not generate heat, but the higher “R-factor” causes your house to be warmer than it would be without the insulation.
But having said that, I happen to believe, like you, that the case for CO2 warming has been greatly overstated.
There are holes in the longwave spectrum that let heat escape freely. And even at wavelengths with high CO2 absorption, the heating effect is countermanded by the rising of heated gases through convection, which cools things back down a bit. Also, CO2 is present only in trace amounts, so the total heat capacity is low and easily saturated (within the few hundred feet above the surface).
So, we do have some so-called “green-house” heating effects on one side, and various cooling effects on the other. What’s the bottom line? Who wins this heating vs. cooling tug of war?
The answer lies up on Mars.
[broken_record]
Mars is a perfect laboratory to test the so-called “CO2 warming” hypothesis (because there is no pesky nitrogen, oxygen or water vapor to complicate the issue). Mars’ atmosphere is 95% CO2. Though much thinner, it contains almost 30 times as much CO2 per surface area unit, than Earth. Yet, it has virtually no greenhouse warming effect: the mean surface temperature is very close to the theoretical black body temperature of 210 Kelvins.
Mars Facts http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html
Visual geometric albedo 0.170 (Earth 0.367)
Solar irradiance (W/m2) 589.2 (Earth 1367.6)
Black-body temperature 210.1 K (Earth 254.3 K)
Average temperature: ~210 K (Earth 287 K)
The warmists always say that all we need is a “trace” of CO2 to create catastrophic warming. So, why doesn’t 950,000 ppm on Mars have any significant warming effect on that planet?
[/broken_record]
“Any effect from anthropogenic CO2 is down in the noise, and is too small to be measured. That is why there is this endless argument. Because if the effect from CO2 was large enough to measure, the argument would be settled.” (Smokey)
Ah, dear sir, but you’re ignoring the powerful juju effects of sudden and devastating tipping points, foolproof computer models understood only by anointed scientists, the sublime theology of forcings, the looming spectre of runaway greenhouse effects, the mysterious codes and truths emanating from the upside-down graphs, the powerful medicine of hidden declines, magical hockey sticks and such. This over-rated, restrictive and dull, dull, dull “measuring” thingamajing you harp about is so yesterday in this free range, post-normal science universe of ours. Namaste!
Ray B says:
When did the Medieval Climate Optimum or Medieval Warming Period become the Medieval Climate Anomaly? Maybe I am reading something into it that shouldn’t be there, but it sounds like an attempt to marginalize the MWP as anomalous since they have to acknowledge it now.
What amazes me about the rejection of history from the warmist camp is the shortsightedness of that position. They must really, deeply believe their projections (and their own infallibility).
Moderate Republican says:
June 21, 2011 at 7:11 pm
No, but I am sure some people here find it deeply ironic that you are suggesting climate change can have that big of an impact while many here argue the warming we are seeing is of no concern….
===================================================================================
“Someone is arguing that life would just be perfect if CO2 levels were exactly like they were then………..”
Yeah boy, if we could just get CO2 levels back to where they were in the Medieval Climate Anomaly, LIttle Ice Age, Dust Bowl, the Great Chinese Famine, the Russian Famine………………..
How about we go way back to the Devonian extinction when CO2 levels fell?
…everything would be perfect LOL
Who in this world was stupid enough to draw that “0” line at the very top of this chart?
http://www.ianschumacher.com/img/icecores.gif
Smokey says @ur momisugly June 22, 2011 at 6:53 am “And increased CO2 is not only completely harmless, it is a net benefit to the biosphere. Charts on request.☺”
So you have charts that prove that ,more CO2 is of net benefit to the earth’s entire ecosystem based on a definitive and quantitative review of the impact on each and every living thing and natural system? That much be one heck of a chart….
Odd as it may be, there appears to be some science that suggests that your blanket statement above is, um, wrong.
CO2 and Wheat: How We Get Less Protein, More Sugar
Without question, wheat is a staple crop. With the help of corn and rice, wheat provides about 60 percent of the world’s food. Therefore, how wheat responds to enhanced CO2 is a big deal, and FACE study results (for example here and here) are not encouraging: while wheat yields increase, its protein content drops.
Take a recent German study published in Plant Biology for example. Petra Hogy of the University of Hohenheim and colleagues compared wheat grown under today’s conditions (with CO2 levels at about 387 parts per million) with those projected for the year 2050, with CO2 levels around 550 ppm. Hogy’s team found about a seven percent drop in protein content, noting several other changes in nutritional value:
* amino acid concentrations decreased, with greater reductions in non-essential rather than essential amino acids;
* minerals such as potassium, molybdenum, and lead increased;
* minerals such as manganese, iron, cadmium, and silicon decreased; and
* sugars including fructose and fructan increased.
It’s too early to tell how these changes will affect our health and whether the changing chemical properties of wheat will prompt new ways of processing it (e.g., will a changed gluten profile impact bread-making?). However, we can easily speculate that less protein and higher lead levels in wheat will require some adjustments. Perhaps people will have to consume more sugars to get the same amount of wheat protein. Alternatively, maybe new cultivars of wheat will need to be engineered that are better adapted to high CO2 concentrations.
More CO2 Means More Toxicity in Some Plants
A number of other (mostly chamber) studies suggest that the toxicity of some crops will increase with rising CO2 levels. Of particular concern is cyanide.
About 60 percent of today’s crop plants are cyanogenic, meaning that when their leaves are chewed or crushed, cyanide is released as a defense mechanism. A series of papers by Roslyn Gleadow of Monash University and her colleagues find that many cyanogenic plants will have greater cyanide toxicity when CO2 concentrations are higher.
CO2, Clover, and Cyanide
While we humans don’t usually eat clover, foraging animals like cows and sheep do, so how clover responds to elevated CO2 is of interest.
A recent study led by Gleadow, published in the Journal of Chemical Ecology, found that while cyanide levels in clover grown under ambient (360 ppm) and elevated (700 ppm) CO2 levels did not rise, protein content dropped some 25 percent — in other words, the cyanide-to-protein ratio increased.
This is important because the ability of livestock to tolerate cyanogenic compounds depends on their protein intake. The more protein they take in, the more cyanide the animals can handle and vice versa. In controlled greenhouse experiments, Gleadow’s group found that the relative ratio of protein to cyanide dropped by 30 percent or more, suggesting that livestock will be exposed to greater amounts of cyanide in a CO2-enhanced world. This could also mean that livestock may need to forage more to get the same amount of protein to combat the cyanide, which could lead to other downsides like more waste and methane production.
CO2, Cassava, and Cyanide
Cassava, also called manioc, is a cyanogenic staple that supports hundreds of millions of people. The starchy tuber’s leaves and roots are critical to tropical populations in Latin America, Africa, and Asia, despite its harmful amounts of cyanide. (We Westerners tend to eat it as tapioca.) A Gleadow study published in Plant Biology found that while growing cassava at CO2 levels of 710 ppm had no effect on the cyanide in its root, it doubled the plant’s cyanide levels in its leaves and shrank the tuber’s size.
To remove the cyanide and make it safe for eating, cassava is generally rasped, fermented and dried, but residual amounts remain. In a typical year, for instance, flour in Mozambique markets has been found to have cyanide levels ranging from 20 to 40 ppm but in a drought year (cassava is a very drought-resistant crop), cyanide levels have been found to be as high as 100–200 ppm. The World Health Organization recommends a limit of 10 ppm cyanide in food.
Cyanide poisoning, which can be fatal, can disrupt normal endocrine function and impair neurological function. Konzo, a form of cyanide poisoning that causes leg paralysis, already affects nine percent of Nigerians. Not a good situation, and one that could grow unless alternate cassava varieties are developed with lower concentrations of cyanogenic compounds. (And strangely at present, according to the Encyclopedia of Food and Culture, ”many farmers prefer to cultivate the high-cyanide varieties for reasons that are not entirely clear.”)
All these studies at the intersection of crop nutrition and enriched CO2 levels illustrate the complex ways that the natural system can respond to changes and perturbations which in turn can have serious ramifications for humans. It’s another geo-engineering quandary: stop CO2 increases and avoid the crop changes, or allow CO2 to increase and find a workaround like developing new cultivars that compensate for the nutritional changes.
http://www.nicholas.duke.edu/thegreengrok/fertilizationeffect
Moderate Republican,
A fine cut ‘n’ paste job from an alarmist blog that gives very little in the way of real world data, eg: what is the ratio of proteins to sugars? Your blog ‘authority’ doesn’t say. And the scare tactic of trying to link more CO2 with cyanide deaths is par for the alarmist course. Where are all the bodies poisoned by cyanide from rising CO2? Show us even one.
Like most everything else you assert, your claim that wheat doesn’t respond well to higher CO2 levels is simply wrong: click
For plenty more info on pllants benefitting from higher CO2, see here.
There is plenty of real world evidence contradicting your nonsense:
click1
click2
click3
click4
click5
click6
click7
The findings in the last link state:
That debunks the baseless blog alarmism that you cut ‘n’ pasted. Folks in Illinois know something about farming. You should listen to them instead of the credibility-challenged goofball you linked to.
Like everything else you give your opinion on, this has been covered in detail in the archives. Do a keyword search and try to get up to speed.
Smokey says @ur momisugly June 21, 2011 at 7:16 pm “where we demand verifiable facts and evidence, not true belief. ”
So totally fair to hold you to this standard then, right? Seems fair – and there is a goofy amount of pseudoscience in your post above.
To pick just two;
From the one of the paper you cite ‘The notion here is that if the trees are producing more high-quality seeds at high CO2 compared to grasses and herbs, then the trees may be at an advantage,” Advantage – as in grasses and herbs not doing as well. You need to prove that is a net-benefit.
A YouTube video of an artificial and optimized and controlled and indoor crop environment where;
* a singe plant species
* with no competing plants
* in a temperature controlled for optional growth
* in a moisture controlled for optimal growth
* in an unlimited and optimized nutrient controlled for optimal growth
environment
is not evidence of anything approximating how Earth’s ecosystems behaves. Those
You said “CO2 is not only completely harmless, it is a net benefit to the biosphere.” and “where we demand verifiable facts and evidence, not true belief. ”
You are far, far, far away from that standard. And here is a hint – science doesn’t use words like “completely” for a reason.
For MR and others:
http://www.climate4you.com/ClimateReflections.htm#20080927:%20Reflections%20on%20the%20correlation%20between%20global%20temperature%20and%20atmospheric%20CO2
CAGW or AGW has been falsified. CO2, at most, has a minor role in climate change.
Moderate Republican says:
June 22, 2011 at 11:35 am
“CO2 and Wheat: How We Get Less Protein, More Sugar”
Oh come on, if that’s a problem for you you can always switch to legumes.
“Will Elevated Carbon Dioxide Concentration Amplify the
Benefits of Nitrogen Fixation in Legumes?”
http://www.plantphysiol.org/content/151/3/1009.full.pdf
Nobody said we need to plant the same amount of the same stuff each year.
I notice MR did NOT claim human emissions cause warming, but instead that human emission are changing the atmosphere. Is that misdirection, or is he mistating the issue?