Talk:Little Ice Age/Archive 2

Archive 1

Archive 2

questionable graph ( but my debian pdf reader scrolled to page 16 !)

Wow, I just loaded original source for graph, apparently this,

"...he figures used to generate this plot were obtained from the IPCC Working Group I Fourth Assessment Report Summary for Policymakers, page 16. [1]" and nothing bad happened. Anyway, from what I can tell, this has nothing to do with litte ice age, but relates to the atmosphere circa 2005, "FIGURE SPM-2. Global-average radiative forcing (RF) estimates and ranges in 2005 for anthropogenic" . While this is ancient history for PC's and teen fashions,it is hardly a geological time scale likely to be relevant to this topic. Nerdseeksblonde (talk) 11:13, 30 November 2009 (UTC)

So, I guess my concern was just that it didn't look right in context- the anthro terms for this topic may have significance but most literature makes out to be only one component. But, this graph seems to apply to a different time period and only appears to consider anthro terms. So, it may be misleading because it doesn't apply or I misread something and the text should make clearer why it is relevant and in context. Nerdseeksblonde (talk) 11:16, 30 November 2009 (UTC)

to wit, radiative forcing functions seems misleading,

http://en.wikipedia.org/wiki/File:Radiative-forcings.svg Nerdseeksblonde (talk) 13:33, 30 November 2009 (UTC)

Sorry, I guess that title isn't quite right but it is the "Radiative forcing" chart and I meant to include in prior posts just was always the last thing and I was taken by the working pdf viewer :) Anyway, there is only one chart AFAIK that lists contributions and it is labelled "Radiative" and it applies to atmosphere circa 2005 AFAIK but please correct if wrong here. Nerdseeksblonde (talk) 13:39, 30 November 2009 (UTC)

It is also the only graph to mention a halocarbon contrib. Remember all those cans of RAID they sprayed to try to eliminate fleas carrying the plague? Neither do I. LOL. Nerdseeksblonde (talk) 13:58, 30 November 2009 (UTC)

I don't think the answers have changed much since, so I don't care too much about it being updated. Is there anything better than tha AR4 numbers anyway? William M. Connolley (talk) 18:01, 18 December 2009 (UTC)

Shutdown of thermohaline circulation

William M. Connolley removed the Shutdown of thermohaline circulation (originally "Ocean Conveyor Shutdown") (Shutdown_of_thermohaline_circulation)from the causes of the Little Ice Age section. I have restored this portion of the article including references from NASA and an article from the Times. I hope this satiates Mr. Connolley's desire for references. Regards, Rowlan (talk) 15:44, 18 December 2009 (UTC)

• User:William M. Connolley/For me/The naming of cats William M. Connolley (talk) 16:45, 18 December 2009 (UTC)

Excuse my ignorace, DOCTOR. I'll make sure to properly tip my hat to you also. Rowlan (talk) 17:37, 18 December 2009 (UTC)

• I doubt it. It certainly does not satisfy (nor satiate) mine. None of the two sources mentions the little ice age - as far as I can tell, not even remotely. I've removed the section. If you can find a reliable source that suggests that the LIA is connected to a slowdown (or shutdown) of the thermohaline circulation, feel free to add it back. But sources that talk about changes in the thermohaline circulation 13000 years ago, or possibly in the future, don't support the case for a connection with the LIA. --Stephan Schulz (talk) 16:48, 18 December 2009 (UTC)

I've found more refrences, and you can now end your campaign of vengence against this theory.Rowlan (talk) 16:54, 18 December 2009 (UTC)

Are you talking to Dr. Connolley or to me? --Stephan Schulz (talk) 17:22, 18 December 2009 (UTC)

I'm talking to the pair of you. I see how my comment could be unclear, so I've seperated it into to parts. Rowlan (talk) 17:38, 18 December 2009 (UTC)

Ok. I've fixed the formatting. I still don't think the current text is acceptable. The Fagan book is the only source for the connection between thermohaline circulation and LIA so far, and it only mentions the theory with a big question mark and in passing. As far as I can tell, Fagan got it from Wally Broecker. We might be able to find a better source for the theory in his The Role of the Ocean in Climate, available here. But even then there still is no source connecting the possibility of changes in the conveyor in the LIA with concerns that this may happen as a result of current global warming - unless such sources are found, this is a textbook case of WP:SYN, and not acceptable under our no original research policy. Sorry that we are so anal - all the climate articles are contentious because of the political debate about global warming, and the best way to avoid descending into a shouting match is the insist on reliable sourcing following WP:V. --Stephan Schulz (talk) 18:08, 18 December 2009 (UTC)

I've removed the section agani. It doesn't look to me like you've addressed the problems - the BBC ref is unusable William M. Connolley (talk) 17:59, 18 December 2009 (UTC)

Dr. Connolley, why is the BBC ref unusable? Also, I've referenced a book on the topic. I believe the claim is substantial enough to leave. I've provided supporting evidence that is suffice enough to list as a Theory of The Cause of the LIA. I'm restoring it as it was, please leave it. I will continue to add references as I find them.Rowlan (talk) 18:15, 18 December 2009 (UTC)

For a start, I don't see where it mentions LIA. But more, its just some talking heads being quoted badly out of context to make up a prog. This isn't Lord Reith's BBC William M. Connolley (talk) 18:21, 18 December 2009 (UTC)

It does mention the LIA if you read it in entirety. Also, you aren't the end all be all of judgement. It's a theory, which implies that it's a topic that is up for debate. It is a valid theory, and I will fight for it to stay. It is now probably the 3 sentences with the most referrences in this whole article. Rowlan (talk) 18:47, 18 December 2009 (UTC)

It's a theory, but as far as I can tell one with fairly few adherents, the most notable of which is Broecker. If it stays, it should probably be attributed to him. Please try to find good sources - no mountain of blogs and similar sources is useful, and sources that don't support the main claim are worse than useless - they only confuse. --Stephan Schulz (talk) 18:52, 18 December 2009 (UTC)

I've not posted any blogs as sources. I'm not pulling this from some random dude writing about global warming. All the ref's are from scientific journals, and articles. I'm also including one from Broecker (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC34299/). I hope this helps to ensure that this contentious theory stays around.Rowlan (talk) 19:00, 18 December 2009 (UTC)

Universe today is a decent site, but essentially a blog. Some of the sources you added later are much better, and support this at least as a theory. But it still needs clean-up, and I still see no connection to a possible future change connected to the LIA. --Stephan Schulz (talk) 19:14, 18 December 2009 (UTC)

I still can't see where the BBC refs the LIA. Please quote, here, the section you mean from the BBC page. Adding lots and lots of refs isn't a sign of strength. Take out all the weak ones. I've removed some William M. Connolley (talk) 22:27, 18 December 2009 (UTC)

Your edit definitely helped the wordiness of the first sentence. I've re-added the 2 ref's for the last sentence. I think taking them away dilludes the credibility to those theories. I'll compromise where I can, as that's the only way to achieve anything on here, but I am monitoring this to ensure that it stays as a valid concept about the origins of the LIA. This topic has been featured on at least 3 large networks, the BBC, the History Channel, and PBS. People who see these programs will be looking for this theory as it is promoted by the historians and scientists giving commentary. I hope we are now past trying to qualify it's existence.

My one question is should the named be changed from "Ocean conveyor shutdown" to "Thermohaline circulation shutdown" with a reference to ocean conveyor shutdown as an alias? Rowlan (talk) 23:10, 18 December 2009 (UTC)

Anglo-Saxon Chronicles

"Among the earliest references to the coming climate change is an entry in the Anglo-Saxon Chronicles dated 1046". Either Burke isn't a source we can rely on for this kind of thing or this is not a fair representation of what he says. There is "no entry in the Anglo-Saxon Chronicles dated 1046" referring to a severe winter. There is one in Ms. C (the Abingdon Chronicle), s.a. 1046, but only in that one manuscript. In Ms. D it is placed in 1048. It doesn't appear at all in the other two witnesses, Mss. A and E. And there's nothing terribly untypical about this kind of report anyway. The Chronicle of Ireland averages more than one severe winter per century in the C8th and C9th and one of those in the same year as reports of the Seine, Danube, Rhine and Elbe freezing over in the Royal Frankish Annals. And that's in 821/822, earlier and more wide-spread than the supposedly significant events c. 1046. Better to drop this I think. Angus McLellan (Talk) 21:28, 20 December 2009 (UTC)

Agree. A single cold winter is insignificant for climatic trends, and 1046 is two centuries or so too early - it's square in the middle of the conventional dating of the Medieval Warm Period. --Stephan Schulz (talk) 21:58, 20 December 2009 (UTC)

Article probation

Please note that, by a decision of the Wikipedia community, this article and others relating to climate change (broadly construed) has been placed under article probation. Editors making disruptive edits may be blocked temporarily from editing the encyclopedia, or subject to other administrative remedies, according to standards that may be higher than elsewhere on Wikipedia. Please see Wikipedia:General sanctions/Climate change probation for full information and to review the decision. -- ChrisO (talk) 02:59, 2 January 2010 (UTC)

Failure to understand "inherent variability"

Saying that "inherent variability" is an explanation of the Little Ice Age is idiotic. One might as well say that the temperature went down because it went down. —Preceding unsigned comment added by 86.169.202.217 (talk) 09:32, 7 January 2010 (UTC)

Not really. If I say that the darkness of the polar winter is a part of the inherent variability of light levels at the surface of the earth at high latitudes, whilst the darkness of the ocean depths is due to the absorption of light by the intervening volume of water, I think that gets the message across. There are better ways of putting it, though. And that is probably also the case here. --TS 10:32, 7 January 2010 (UTC)

The point is that there is no need for the LIA to have a "cause". It is all too easy to assume that just because there was a temperature fluctuation it must have had some external "cause". Including internal / intrinsic variability makes this point; but maybe it needs to be made more clearly. Don't title sections "iditoic"; it annoys people William M. Connolley (talk) 11:15, 7 January 2010 (UTC)

I have no problem with the intrinsic variability thing - pre-panic historians did not assume than the MWP was significantly warmer, or the LIA significantly colder, on average - only that but I have struggled to see where this is discussed in articles on climate here on Wikipedia. A link where the lead says "an inherent variability in global climate" would be helpful. Angus McLellan (Talk) 14:16, 1 February 2010 (UTC)

Climate variablility on WP redirects to Climate change, but I don't see a section there dedicated to chaotic changes, in opposition to forced. This publication makes the distinction [1] "We investigate the roles of climate forcings and chaos (unforced variability) in climate..." so maybe a linkable WP article or section should do this too? (I don't have easy access to academic papers, or I'd tackle it myself). Novickas (talk) 15:42, 1 February 2010 (UTC)

It's important to search for the cause of the little ice age. We search and obtain ideas about causes for smaller scale fluctuations, such as El Nino/La Nina. So of course there's going to be a "cause", and it would be very significant if any group or individual were establish a "cause" for LIA which went on to gain scientific consensus. Among other things, it would be important to know a cause so that such an event might be predicted in advance were the same causal conditions to occur or projected to occur. Retran (talk) 12:13, 20 May 2010 (UTC)

Separately there's the matter of how to characterize the LIA in the first place... was it really colder globally (it wasn't) and did every region experience changes globally, and how much of the global climate should fluctuate before we categorize a period of time into an "age" like this? Are we naming it "LIA" because it happened so recently, and had we had less precision to historically analyze it, would it even be significant on a broader scale? I would think yes... but it ties in with the first question about wheather its important to find a cause. If one argues the futility of finding a "cause" then one is seems to be arguing the LIA was not a climatically important event. (And I think it was, and the scientific consensus is that it was as well) Retran (talk) 12:13, 20 May 2010 (UTC)

Regarding the "unforced" changes and stuff about "chaos"... that seems to be an idiosyncratic (maybe even metaphysical) use of climate terminology. All climate change is forced, period. The problem is determining what mechanism is responsible for the forcing. Changing amount of incoming solar radiation is a forcing mechanism. It seems the astrological mechanisms (Milankovitch cycles) which lead to changes in isolation, the established forcing mechanism between the glacial and interglacial cycles have been ruled out in the case of LIA. "Inherent Variability" isn't a very satisfying explanation... that's just like saying "stuff just happens". Useless. Why bother bringing that up? I'm not looking for a philosophical reason. Science requires searching for a physical observable reason. Anyone not engaged in the search for a observable, testable, predictable, cause for the LIA is not engaged in Science. In fact, the "Inherent Variability" section doesn't belong in a article like this, it represents no knowledge or understanding. Inherent Variability would have to describe something like Milankovitch cycles... and in anything those are a real description of a true inherent variability. The discussions about "chaos" do not belong here. Retran (talk) 12:26, 20 May 2010 (UTC)

Imagine an Earth with no external forcing. There would still be variations in year-to-year, decade-to-decade, etc, average temperatures. Whether you call that climate or cliamte change is a matter of perspective. How large it is remains unclear William M. Connolley (talk) 13:19, 20 May 2010 (UTC)

If imaging an earth with no external forcing, variations would be due to internal distributions in temperature, eventually coming to equilibrium. Climate in the context of climate study, is by definition weather patterns averaged on a 20 scale. How is chaos theory relevant to explaining the LIA? The idea is that some variation occurs without any cause except that variation occurs without cause. Isn't it like saying "welp, couldn't find nothing else so we'll just use Chaos theory"? Seem's like a catch-all. How's this different than saying "It was God's will", etc etc? Chaos theory seems useful in modeling realistic analogies, but not in making these kinds of predictions or explanations. Also, in your imagination exercise you suggest there's no external forcing, but what if LIA was caused by internal forcing? (perhaps it was just an exercise and you were trying to help me understand chaos theory's application better?) Retran (talk) 13:47, 20 May 2010 (UTC)

variations would be due to internal distributions in temperature, eventually coming to equilibrium - no William M. Connolley (talk) 13:52, 20 May 2010 (UTC)

What kind of explanation is "no". Of course internal forcing can influence climate. It's the main type of forcing occurring at the moment. In your exercise of an earth without external forcing, earth would be without any external energy input, the earth's climate would respond to its own processes (there are a few) but eventually the energy would be dissipated. I'll have to call you out as being unserious and marginal if you can't explain this better. Retran (talk) 14:10, 20 May 2010 (UTC)

It isn't an explanation. If you want one: the atmosphere has no stable state, when forced by constant input from the sun. So there is constant chaotic changes in global mean temperature, and those permeate (although at lower power, of course) to longer timescales. However I think atmosphere-only chaos (fixed ocean SST, fixed land temperature) would have negligible power at decadal scales. But there is the ocean too, which generates power at longer timescales William M. Connolley (talk) 14:52, 20 May 2010 (UTC)

"So there is constant chaotic changes in global mean temperature" I suppose it would depend on the temporal scale in question. What is the flux over an hour's time? If the LIA lasted 100s of years; the chaos-theory based forcing would seem to be too weak. Retran (talk) 15:15, 20 May 2010 (UTC)

But the ocean has longer timescales than the atmosphere, and the ice sheets longer still William M. Connolley (talk) 15:47, 20 May 2010 (UTC)

But what is the proposed mechanism affecting change in the chaos example? Ice sheets typically grow as a result of cooling, so "chaos of ice" cannot be the cause here. The atmosphere you've ruled out, so we're left with Oceanic chaos forcing. So how does that work? Any material to cite about this? Retran (talk) 17:19, 20 May 2010 (UTC)

It is hard to talk in terms of a "mechanism"; it is mere internal fluctuations in the climate system. To say just that ice sheets just grow as a result of cooling is too facile; one mechanism proposed for D-O oscillations of a semi-chaotic process whereby the icesheets grow, "beyond their means", calve and shrink and re-grow. Sources? What about the "Inherent variability of climate" section? William M. Connolley (talk) 21:34, 20 May 2010 (UTC)

"To say just that ice sheets just grow as a result of cooling is too facile"... what does that mean? Specifically, as far as what "kind" of global cooling causes icesheets to grow when average highs are reduced in the nothern hemisphere's summer. For ice-sheets to grow, they must have an area with temperatures that do not fall often below freezing during the summer, (and some amount of precipitation). The idea of the LIA is that there was an growth in glacial coverage. The chaos idea does not explain how/why this would happen.... that is it does not seem to be addressing summer maximum temperatures. Retran (talk) 22:54, 20 May 2010 (UTC)

Also... "it is mere internal fluctuations in the climate system" does not specify WHICH climatic interactions are being affected, and why it leads the change that was observed. Something proposed, some sort of math, anything, since we're dealing with science. We shouldn't rely on synonyms of "stuff changes, stuff happens" like "inherent variability". A wikipedia article is not itself a source, but if you're referring to the two citations included in the section, I'm asking specifically how you would tie the sources regarding the mechanisms. If a model was indeed produced that predicted LIA-like outcomes, the model would have a record of what interactions (the chaos-forcing) in the climate occurred on its run. Retran (talk) 23:11, 20 May 2010 (UTC)

(od) Sorry, I dropped the conversation. Feel free to browse Wikipedia:General_sanctions/Climate change probation/Requests for enforcement#William_M. Connolley .28revisited.29 if you're wondering I'm busy. My savage attacks on you above feature, if you're interested. Anyway: facile: two ways. Firstly, because as I said they don't just have to grow: they can end up oscillating (maybe): see Dansgaard-Oeschger_event. Or secondly because more cold means less snow means less ice sheet. The chaos idea does not explain how/why this would happen: well no, indeed. That is the point of chaos. Other than "it is part of the dynamical system". You don't really get an explanation of why individual weather events happen, either, other than a trail of not-really-explanatory causes.

The ice cover has three possibilities: its growing, shrinking, or staying the same. "Oscillation" describes a purported regular phase change back/forth. If it's an oscillation you're proposing, the LIA would be a phase change to a growth. Retran (talk) 21:28, 28 May 2010 (UTC)

"more cold means less snow means less ice sheet" How does "more cold" lead to "less snow"? Lower temperatures lead to greater precipitation (snow in this case) because a lower temperature reduces the maximum amount of H2O able to be held in air.Retran (talk) 21:28, 28 May 2010 (UTC)

If "chaos" does not explain anything, why include it? I assume you're not that cynical, you must think it explains WHY it happened or you'd have just been wasting all your time arguing against its removal from this article.Retran (talk) 21:28, 28 May 2010 (UTC)

Thanks for letting me know about the mini-controversy that seemed to have you temp banned. For what it's worth I have found your behavior toward me here to be fully acceptable, we're just two people discussing specifics on a scientific topic and I never saw any overpersonal or abusive angle to them.Retran (talk) 21:41, 28 May 2010 (UTC)

"it is mere internal fluctuations in the climate system" does not specify WHICH climatic interactions are being affected - agreed. If you're explanation is "chaos in the dynamical system" then a halfway decent explanation needs to tell you what that system is and what its components are. "stuff changes, stuff happens" like "inherent variability" - but now you've jumped too far. AS far as I know, no-one has a particularly clear idea of exactly what internal fluctuations might have caused the LIA. Jumping from that to "the explanation is nonsense" is wrong William M. Connolley (talk) 22:00, 23 May 2010 (UTC)

Why should the chaos method be included if there are not any associated climatic interactions to describe? Other ones do describe climatic interactions: sunspots = reduction in incoming sunlight (less heat=more cold), reduction in greenhouse gases (less shortwave energy (sunlight) converted to longwave (heat)= less heat = more cold), volcanic activity (ejects ash, ash reflect sunlight, less sunlight = less heat = more cold). Those are examples of interactions and if those specifically are not clear enough in this article they need to be written so the interactions ARE clear.Retran (talk) 21:28, 28 May 2010 (UTC)

Farcical Article

This article is farcical in its blatant pro-AGW bias, who's going to clean it up ? SunSpot (talk) —Preceding unsigned comment added by 206.47.249.251 (talk • contribs) 20:25, 3 May 2010

Please feel free to make constructive edits, and especially to provide evidence that the science presented in this article does not correctly represent the synthesis of scientific views as presented in the peer reviewed literature, with due weight given to comprehensive review articles. Tasty monster (=TS ) 14:31, 20 May 2010 (UTC)

Thank YOU for mentioning the weight to be given to review articles. There are many "one-off" ideas that are presented in peer-review articles... inclusion in review articles is one important step in establishing importance/relevance/consensus of a scientific idea. Far more sense than relying the number of Google Scholar hits. Retran (talk) 17:16, 20 May 2010 (UTC)

SA sediment cores

This [2] is a step in the right direction but isn't good enough. If there are only conf anstracts, and it didn't make it into any papers, then it should come out William M. Connolley (talk) 21:46, 8 February 2010 (UTC)

[3] -Atmoz (talk) 21:27, 9 February 2010 (UTC)

Is that the same thing? Only one author in common, but the same link. I can't access it: what does it say? 4 years later, has their text changed (well, if it is still the same paper, of course) William M. Connolley (talk) 21:56, 9 February 2010 (UTC)

It looks like the paper corresponding to the conf abs is [4], but it doesn't actually mention LIA. Another paper in the special section is [5] which mentions LIA several time saying "...during the southern-hemisphere equivalent of the Little Ice Age" in the abstract, but waffling ensues. [6] is much stronger "The A.D. 1490–1700 wet period is associated with the onset of the European Little Ice Age (LIA) and interpreted as its local signature. This work supports the fact that the LIA was a global event, not only restricted to the Northern Hemisphere." -Atmoz (talk) 22:11, 9 February 2010 (UTC)

I hate it when they do that. It isn't the "Little Wet Age". This is just humans-can-find-patterns stuff William M. Connolley (talk) 22:34, 9 February 2010 (UTC)

The term "Little Ice Age" is based an early description and naming that became popular (as the article states). When temperature is cooler and moisture content remains the same, precip increases. Perhaps it would be helpful to include details about the proposed differences between the global/regional high/low systems of today vs. the LIA. Retran (talk) 13:24, 4 May 2010 (UTC)

When temperature is cooler and moisture content remains the same, precip increases. - no: in general, the cooler it is, the less precip. Which is why Antarctica is argey a desert and the highest rainfals occur in the tropics William M. Connolley (talk) 21:52, 28 May 2010 (UTC)

Antarctica's desert climate is best explained as a result of it's latitudinal location (hadley cells), and large size (continentality). You seem to have ignored "and moisture content remains the same". (Rain occurs with varying degrees of volume due to its proximity to air masses with high mositure content.) A body of air with a certain moisture content that reduces in temperature past its dew point will condensate into precip. In the case of LIA, are you arguing for discussion within the article as to the relevancy of its name?Retran (talk) 22:24, 28 May 2010 (UTC)

Black Death as a cause of the Little ice Age?!

The current Little Ice Age entry provides several possible causes of the LIA: "Several causes have been proposed: cyclical lows in solar radiation, heightened volcanic activity, changes in the flow of ocean currents, an inherent variability in global climate, and decreased human populations due to the Black Death and the Columbian Exchange." Excuse me but how on earth could either the Black Death or the Columbian Exchange cause climate change?!!! —Preceding unsigned comment added by 81.149.35.75 (talk) 14:00, 1 February 2010 (UTC)

The idea there is that humans were already affecting climate by clearing forests for agriculture. So if they died off in sigificant numbers the forests grew back and captured carbon. More here [7]. Novickas (talk) 17:27, 1 February 2010 (UTC)

How mainstream are the ideas about "Black Death" and "Columbian Exchange" in the field of global climate change, or does that necessarily matter? Both remain rather controversial explanations for LIA scientifically (even given the consensus of modern climate change due to fossil fuel use since industrial revolution). That doesn't mean they will always remain scientifically controversial; but do they warrant current inclusion in an encyclopedia article? Retran (talk) 13:33, 4 May 2010 (UTC)

I saw a disclaimer was added "This hypothesis has not gained widespread scientific support." but I feel that is not adequate. The idea that humans contributed to warming of the earth (however slight but detectable) thousands of years before present has only just NOW began to be noticed and accepted in mainstream climate science. Then combining this idea with "Black Death" and "Columbian Exchange" by saying one or the other caused an interruption in this warming, would be really stretching it. The problem is the Black Death and the Columbian Exchange occurred at two different times, and two times recent enough that we should be able to deduce which, if either, it was. Which was it? And if the studies pin different ones down, they conflict each other by too much for so recent of a date to be acceptable for mention in an encyclopedia, since its a scientific discussion in the periphery... nothing close to established.Retran (talk) 12:05, 20 May 2010 (UTC)

IMO Ruddiman's hypothesis can be included under WP:NPOV 'significant views that have been published by reliable sources'. A Ruddiman article, 'The anthropogenic greenhouse era began thousands of years ago', is cited 285 times in Gscholar. [8] Its abstract contains the sentence 'Plague-driven CO2 changes were also a significant causal factor in temperature changes during the Little Ice Age (1300–1900 AD).' [9]. That he went on to include the depopulation of the Americas is refd here - also in his own book he states 'The correlation between the two signals is striking: every major CO2 decrease lines up with an episode of mass mortality in Europe and China or the Americas." [10] Weighting of course is always an issue. But right now it's last in the article's list of suggested causes, accommodating its recency. Novickas (talk) 16:26, 20 May 2010 (UTC)

Ruddiman is noteworthy and ideas are taken seriously in the scientific community, but are controversial. I'm pointing out that the Plague and the "Columbian Exchange" are separate events. In the article, which are we to cite as the proposed cause? If they are to be seen as a single event (new to me) what precedent in a noteworthy source exists? Also, its extremely inadequate to include a cheesey disclaimer "....has not gained widespread scientific support".... if it hasn't, it is inappropriate to include it in this article, this is an article about a scientific topic and scientific support should be the standard for inclusion. If it's gained noteworthyness, it would be helpful to include where it's gained support and what it's helped explain that other hypotheses have not.Retran (talk) 17:09, 20 May 2010 (UTC)

Also, we need more than one individual writing papers that support a hypothesis to indicate that its built up a consensus enough that its warrants inclusion in an encyclopedia, (even a controversial hypothesis neeeds this kind of rigor to warrant inclusion I feel) Retran (talk) 17:13, 20 May 2010 (UTC)

It would be nice to expand it but that'd be a lot of work. I feel that the summarized inclusion plus the disclaimer is enough for now given the 285 Gscholar cites and about 100 discussions in secondary sources, i.e. Gbook findings for "The anthropogenic greenhouse era began thousands of years ago" ruddiman". [11]. If you see the disclaimer as cheezy pls rewrite it. Novickas (talk) 17:40, 20 May 2010 (UTC)

Where is it stated that its appropriate practice to rely on Google Scholar hits as a metric for inclusion? I'm REFUTING that point. It needs to be in review articles. And I'm also arguing that it's un-encyclopedic to use a disclaimer statement of ANY type about the information. It needs to be removed and the content adjusted to describe its current scientific acceptance status. If there is not any, if it's still marginal, the references should be removed. Gscholar is NOT the way to determine this, that's WRONG. Retran (talk) 21:15, 20 May 2010 (UTC)

If you feel that strongly about it, go ahead and delete the hypothesis. No one else here is supporting it and I'm unlikely to devote the time/energy that you see as necessary for its inclusion. Novickas (talk) 21:59, 20 May 2010 (UTC)

Thanks for discussing this seriously. I feel we should see if we can gain a consensus about rewriting the section, taking into account the points I mentioned. I only countered at the points you mentioned because they didn't seem to take into account what I said previously... I am too skeptical to have a strong emotion tied to this hypothesis one way or another. I just feel it should be addressed in a more encyclopedic way. Also, I feel it wouldn't be my place to delete that hypotheses at this point. I will probably take some time in the next day or so to find review articles on this hypothesis, and if they don't exist, then we'll have to take seriously the idea of deleting it or some other remedy. If review article do exist, (they would probably be based on Ruddimen's line of thinking) I will attempt to rewrite the section based on that, and I will of course be happy to subject it to the rigors of consensus here in discussion.Retran (talk) 23:02, 20 May 2010 (UTC) --- oh and this idea has far more serious attention than the "Chaos/inherent variability". Retran (talk) 23:05, 20 May 2010 (UTC)

Well that would be just wonderful. I don't have access to JSTOR etc at home and am not so happy with the free-access stuff about this. The article really does need a fair amount of balance work - no one has seriously worked on it for some time now and the area is terribly contested just now. Novickas (talk) 01:15, 21 May 2010 (UTC)

Ruddiman (a very well-respected researcher by others in the field) proposed several different hypotheses, both on long-term issues (agriculture, animal husbandry) and short-term CO2 jiggles caused by plagues. He certainly does *not* think the Black Death caused the LIA. He does think a ~50M-person post-Columbus die-off *contributed* to unusual drop in CO2 from 1550 to ~1600AD, due to reforestration in the Americas, and preceding the Maunder Minimum. See the red section of Law Dome CO2. The Black Death might have had some effect on the smaller 1350-1400 drop. The difference is that the American die-off happened in areas with huge potential for dense reforestation.

When someone serious proposes startling new hypotheses, scientists don't just accept them, but some start looking harder. Hypotheses get rejected or refined, new papers appear, inciting yet more research. There are already a various papers, some by other authors, on rice paddy archaeology, glacier modeling, agricultural footprints, charcoal patterns in the Americas, etc. Data is piling up and it tends to support Ruddiman more than refute him. People are busy refining uncertainty bounds, but in general, support is slowly building, although some may never accept it, no matter what. It is hard for a casual reader to see, because the work is very interdisciplinary, and the papers are spread across often-obscure journals read by different specialists. Although I've only seen a few of the forthcoming articles in review, there is a big issue of The Holocene coming out later this year with many articles that may pull this together. Then we'll see. JohnMashey (talk) 16:11, 20 August 2010 (UTC)

Ambiguous dates for winter

In the winter of 1780, New York Harbor froze

the unusually harsh winter of 1565

There are reports of heavy snowfalls in the winters of 1665, 1744 and 1886.

There are several references to winter occurring in single specific years in a northern-hemisphere context, of which the quoted examples above are a sample. These references are ambiguous because each northern winter spans two years (the end of one year and the beginning of the next), so it is not clear which winter is intended. These need to be clarified to remove the ambiguity. -- B.D.Mills  (T, C) 04:30, 15 July 2010 (UTC)

A Ph.D. in climatology doesn't qualify a person to be called "a scientist"

WMC has twice reverted this change [12], when the first source clearly identifies Tim Ball as the source; a gentleman with a Ph.D in climatology and many published research papers. I anxiously await the reasoning for not calling this man "a scientist". Fell Gleaming^talk 13:04, 10 September 2010 (UTC)

Check Ball's citation record. Short Brigade Harvester Boris (talk) 13:11, 10 September 2010 (UTC)

Are you claiming a person with a Ph.D. in climatology isn't qualified to be called a scientist? A simple yes or no will do. Fell Gleaming^talk 13:15, 10 September 2010 (UTC)

• The sourcing isn't ideal for a scientific matter, the Pittsburgh Tribune-Review from February 10, 2007, reporting on Timothy Ball and the National Post of March 30, 2007, referring to Dr. Syun-Ichi Akasofu. Given more recent developments in science, the past tense would be more appropriate, and describing two scientists with fringe views as "some scientists" is questionable. FellGleaming's additional citations[13] are to a January 2008 New American Magazine article by Akasofu (same guy) and, rather oddly, a Science article from 29 November 1996: hardly indicative of current "belief". The whole section needs to be reviewed, and better sources used. . . dave souza, talk 17:03, 10 September 2010 (UTC)

The claim is that some scientists believe X. If you have a reliable source that states the scientists in question have altered their viewpoint, please present it here. Otherwise, your objection is invalid. Fell Gleaming^talk 17:47, 10 September 2010 (UTC)

The sources show that, as of January 2008, two scientists (retired?) "believed" X. They don't show that they'd published their justification of their "belief" in peer reviewed journals, but do show clearly that these scientists held the views in opposition to the clear majority view. Doesn't justify "some". . . dave souza, talk 17:51, 10 September 2010 (UTC)

I've taken it out again. Tim Ball isn't a climatologist. This is getting silly. The meaning of "some scientist" isn't "I can find at least one person who has some plausible claim to being a scientist, though not in climatology" - that is a violation of WP:UNDUE. "Some scientists" has to mean "is at least a respectable opinion of a moderate fraction in a related discipline". And in the context of a science article, you should be able to find them saying it in a science paper, not a newspaper. This is just yet more disruption by FG William M. Connolley (talk) 21:40, 10 September 2010 (UTC)

Oh, and technically Ball doesn't have a Ph D in climatology, its in geography [14]. Though the subject was indeed climate-related William M. Connolley (talk) 21:44, 10 September 2010 (UTC)

A RS says Ball has a Ph.D. in climatology. And I believe it's rather specious to claim a Ph.D. thesis involving the analysis of climate data as not a Ph.D. in climatology. I'm sure you realize as well as I do the guidelines and variance universities have in granting degrees in interdisciplinary areas like climatology. I'll rework the section to remove the "some" wording Fell Gleaming^talk 22:34, 10 September 2010 (UTC)

He's not an active climatologist, nor is he an active academic. He is an active consultant and pundit, though not a proper researcher. ScienceApologist (talk) 00:59, 11 September 2010 (UTC)

A RS says Ball has a Ph.D. in climatology - I doubt this, but OK, what source is that? Since Ball has a Ph D in geography (albeit in a climate related piece of geography) I'm dubious you can find an RS to say otherwise William M. Connolley (talk) 09:28, 11 September 2010 (UTC)

"a warmer era known as"

I've removed the phrase "a warmer era known as" from the opening sentence. I think it's rather obvious that the Medieval Warm Period was warm, and the sentence flows better without this prhase. The sentence now reads, "The Little Ice Age (LIA) was a period of cooling that occurred after the Medieval Warm Period." I consider this edit purely stylistic, but if anyone objects, let me know and I'll self revert. A Quest For Knowledge (talk) 18:12, 10 September 2010 (UTC)

Good change, the "warmer" phrasing raised the "warmer than what?" question unnecessarily. . dave souza, talk 18:29, 10 September 2010 (UTC)

End of Little Ice Age

I think the little section with the above name should just go. Throughout the article we read that the LIA was a complex series of more or less localised events spanning hundreds of years, with various debates about their relationships, if any. The section 'Dating of the Little Ice Age' explains its topic thoroughly, including the debate about the ending(s), between the mid-19th century, 1919 and even the 1930s. The section in question appears just tagged on the end and ignores all the complexity of the preceding article. Suddenly, the LIA is one thing and its simple end began 'around 1850', before we go into the who-said-what-land of points about global warming today. This reminds me of Carcharoth's point on the arb page about reading the whole article before adding titbits. He was talking about BLPs, but I think this section will never integrate with the rest of this article. Any further academic debate that is published about the ending of the LIA should be covered in situ under 'Dating of the Little Ice Age' and this orphaned section should disappear. --Nigelj (talk) 22:46, 10 September 2010 (UTC)

Well, there was no discussion, but this edit by FellGleaming seems related. There are a few remaining problems. First, the first sentence about the scientific mainstream is now uncited. Second, we don't need all these one- and two-sentence paras and very short sections. Third, we can now see the notability problem very clearly: the mainstream view is A, the International Union for Quaternary Research says B, and two random guys in the world say C. I'm going to try to fix 1 and 2. 3 I'll leave until others have commented. --Nigelj (talk) 23:10, 10 September 2010 (UTC)

the end of the Little Ice Age and the beginning of global warming

It's an interesting coincidence that one of the proposed dates for the "end" of the LIA (1850) corresponds closely with the rise of modern industry, which, of course, began pumping large amounts of CO2 into the atmosphere. This is certainly worth serious consideration. WilliamSommerwerck (talk) 20:59, 25 October 2010 (UTC)

Have any scholarly sources suggested a strong connection between the two? --TS 22:30, 25 October 2010 (UTC)

Inuit have an oral record that at the beginning of the industrial revolution, the temperatures were like minus 50 degrees and below. Signs are mist due to the fact that the air was so cold, but now a days, we do not get this cold mist. Now the normal cold temperature is like minus 30 degrees celcius. —Preceding unsigned comment added by 65.181.32.135 (talk) 23:03, 9 February 2011 (UTC)

Kaufman et al.

Kaufman, D. S.; Schneider, D. P.; McKay, N. P.; Ammann, C. M.; Bradley, R. S.; Briffa, K. R.; Miller, G. H.; Otto-Bliesner, B. L.; Overpeck, J. T.; Vinther, B. M.; Abbott, M.; Axford, M.; Bird, Y.; Birks, B.; Bjune, H. J. B.; Briner, A. E.; Cook, J.; Chipman, T.; Francus, M.; Gajewski, P.; Geirsdottir, K.; Hu, A.; Kutchko, F. S.; Lamoureux, B.; Loso, S.; MacDonald, M.; Peros, G.; Porinchu, M.; Schiff, D.; Seppa, C.; Seppa, H.; Arctic Lakes 2k Project Members (2009). "Recent Warming Reverses Long-Term Arctic Cooling". Science. 325 (5945): 1236–1239. doi:10.1126/science.1173983. PMID 19729653.{{cite journal}}: CS1 maint: numeric names: authors list (link) looks relevant, worth summarising related points. . . dave souza, talk 12:04, 11 September 2010 (UTC)

Grindelwald

Many of the now famous glaciers of Switzerland had actually never existed during the Middle Ages, and were only formed during the Little Ice Age. But since the area had already been settled by humans in the Middle Ages, some villages now had to be abandoned again during the Little Ice Age and re-located beforethe advancing glaciers. Grindelwald is an example of an old medieval village "displaced" by the glacier during the Little Ice Age.--dunnhaupt (talk) 21:56, 3 January 2011 (UTC)

Discrepancy? re: "Little Ice Age definition". Earth Observatory. http://eobglossary.gsfc.nasa.gov/Library/glossary.php3?xref=Little%20Ice%20Age. Retrieved 2007-08-02.

This article states, in the introductory, first paragraph, "It is generally agreed that there were three minima, beginning about 1650, about 1770, and 1850, each separated by intervals of slight warming." However, the source states, "Little Ice Age[:] A cold period that lasted from about A.D. 1550 to about A.D. 1850 in Europe, North America, and Asia. This period was marked by rapid expansion of mountain glaciers, especially in the Alps, Norway, Ireland, and Alaska. There were three maxima, beginning about 1650, about 1770, and 1850, each separated by slight warming intervals." Notice the difference of "minima" stated in this article versus "maxima" stated in the source. As a layperson and not a scientist, I find this difference quite confusing; I am seeking comments to determine if the three given dates are temperature minima (meaning low temperatures) or maxima (meaning?) P.S. The source should be updated to: http://earthobservatory.nasa.gov/Glossary/?mode=alpha&seg=l&segend=n , if this source will continue to be used.CM2G0005 (talk) 05:45, 26 February 2011 (UTC)

Good catch. However, the source makes sense only if "the mountain glacier expansions" had maxima at those dates since the end of the sentence clearly says that it was warmer between the "maxima's". Q Science (talk) 08:05, 26 February 2011 (UTC)

Types of changes in the sun

We have article on the following:

1. Solar variation: the change in the amount of radiation emitted by the Sun
2. Solar cycle: a periodic change in the amount of irradiation from the sun that is experienced on Earth
   • I had thought that the latter was the right place for information about the 11-year sunspot cycle.

Also, I understand that it is not variations in the amount of sunlight but in the number of sunspots, that (supposedly, but disputedly?) correlates with changes in terrestrial temperature. If there are any peer-reviewed scientific papers about this, we should mention them. Or even if it's in science textbooks or some university science department's website. --Uncle Ed (talk) 19:19, 8 June 2011 (UTC)

• Which brings up the interesting question of the Croll cycles, more commonly known as Milankovitch cycles. I've added a subsection with sources showing how this has effected a cooling trend through the MWP and LIA. . . .dave souza, talk 20:39, 8 June 2011 (UTC)

p.s. Ed adapted the SciAm statement "That, in turn, has led to a cooling rate of roughly 0.2 degrees Celsius per 1,000 years" to give a rate of roughly 0.02 degrees Celsius per century. Dunno if that's right..... dave souza, talk 21:01, 8 June 2011 (UTC)

'tis about the Arctic, i'd be cautious about stating that this is a global rate. --Kim D. Petersen (talk) 02:09, 9 June 2011 (UTC) [add: The SciAm article is referring to this paper. Which says -0.22° ± 0.05°C for the Arctic. --Kim D. Petersen (talk) 02:11, 9 June 2011 (UTC)]

Good point, I've put that in a separate sentence specifically tying it to the Arctic, and have added the clarification that in the very long term the rate would be expected to lead to an ice age. . . dave souza, talk 08:22, 9 June 2011 (UTC)

Ed, I suggest you re-read all three articles. The solar cycle is one type of solar variation. Solar energy output is strongly correlated with sunspot activity (although the causal relationships are not too well understood). During the Maunder Minimum and the Sporer Minimum solar activity (and sunspots, and solar energy output) were low for longer periods of time, quite independently of the 11 year solar cycle. --Stephan Schulz (talk) 21:08, 8 June 2011 (UTC)

Science News resource, regarding

Columbus' arrival linked to carbon dioxide drop "Depopulation of Americas may have cooled climate" by Devin Powell November 5th, 2011; Vol.180 #10 (p. 12); excerpt ...

The European conquest of the Americas decimated the people living there, leaving large areas of cleared land untended. Trees that filled in this territory pulled billions of tons of carbon dioxide from the atmosphere, Stanford University geochemist Richard Nevle reported October 11 at the Geological Society of America annual meeting. Such carbon dioxide removal could have diminished the heat-trapping capacity of the atmosphere and cooled the climate, Nevil and his colleagues have previously reported.

Example of depopulation described in Guns, Germs, and Steel. 97.87.29.188 (talk) 23:04, 9 November 2011 (UTC)

This possible cause was already discussed in the "Decreased human populations" section of the article, but I added the Science News reference you posted as an additional citation in the section. By the way, the abstract of the actual paper is here: http://gsa.confex.com/gsa/2011AM/finalprogram/abstract_196092.htm Geoffrey.landis (talk) 20:53, 1 February 2012 (UTC)

New study

http://www.colorado.edu/news/releases/2012/01/30/new-cu-led-study-may-answer-long-standing-questions-about-enigmatic-little may be interesting William M. Connolley (talk) 20:11, 1 February 2012 (UTC)

I added references to this study yesterday. Geoffrey.landis (talk) 20:35, 1 February 2012 (UTC)

So you did; thank you. I prefer to leave these things to settle for a little while rather than adding them immeadiately, which is why I dumped it on the talk page to come back to later. But I don't object to you adding this one William M. Connolley (talk) 20:39, 1 February 2012 (UTC)

It seemed relevant. Particularly the dating section is of interest, since apparently the dates of the LIA are not well constrained. Geoffrey.landis (talk) 20:54, 1 February 2012 (UTC)

• This Science Now article might be a better secondary source, and has an interesting comment from Gavin Schmidt. --Pete Tillman (talk) 22:16, 5 February 2012 (UTC)

Frozen Baltic

I removed "The Baltic Sea froze over, enabling sledge rides from Poland to Sweden, with seasonal inns built on the way". It is an urban legend, not supported by any reliable evidence. The cited source, [15], itself does not cite any source. — Preceding unsigned comment added by Grzes (talk • contribs) 18:53, 9 February 2012 (UTC)

"...with seasonal inns built on the way." Heh. Pity there's no RS. Maybe they were Ice Inns?? <G> --Pete Tillman (talk) 19:17, 4 June 2012 (UTC)

Correlation with lower CO2?

The addition to the lead of "There may be a correlation with lower CO2 atmospheric concentrations (as inferred from ice cores)." doesn't seem to be matched by any text or sources in the article. The lead should summarise the article, not introduce unsupported speculation. . dave souza, talk 16:08, 4 June 2012 (UTC)

Yes, I agree. --Stephan Schulz (talk) 17:35, 4 June 2012 (UTC)

Peterlewis reverted, referring to a curve in the article: this seems to be the Law Dome. I've summarised the source as "Lower CO₂ atmospheric concentrations found in Antarctic ice cores may have resulted from the colder global climate." This avoids the suggestion that CO₂ was a cause, apparently OR by PL. Not sure if this detail belongs in the lead. dave souza, talk 17:46, 4 June 2012 (UTC)

Well, it is mentioned lower down in the article so why not in the lead?Peterlewis (talk) 18:33, 4 June 2012 (UTC)

Inconsistent in a big way

I'm having more than a little trouble squaring this statement:

"[Viewed] hemispherically, the "Little Ice Age" can only be considered as a modest cooling of the Northern Hemisphere during this period of less than 1°C relative to late 20th century levels'

with the entire Europe and North America section, which lists indisputable evidence that the cooling was dramatically larger than 1 degree C. Either the historical record is wrong, or the quote above is. Whichever it is, one or the other needs to be either qualified or removed. MarkinBoston (talk) 00:03, 26 February 2013 (UTC)

Maybe The Intergovernmental Panel on Climate Change Third Assessment Report doesn't know what it's talking about then. 1°C is quite a lot, & averages can be funny. Johnbod (talk) 03:23, 26 February 2013 (UTC)

The problem is with the E+NA section, which is misleading and largely anecdotal (its been stuffed full by LIA-disproves-GW type folk, which is silly). IPCC is more likely correct (though someone could look up AR4 and see if it changed there) William M. Connolley (talk) 09:32, 26 February 2013 (UTC)

Well it did a bit, as the article says. I don't agree with your rather POV assessment. The issue here is one of scale, and cherry-picking instead of averaging. There isn't actually a contradiction. Johnbod (talk) 14:34, 26 February 2013 (UTC)

Four citations of "Burroughs", but where is the reference?

"Burroughs analyzes the depiction of winter in paintings.... Burroughs asserts.... Burroughs states.... Burroughs therefore cautions..." -- four citations of "Burroughs". But where is the reference??

-K. Pfeiffer 178.5.228.111 (talk) 08:53, 8 March 2013 (UTC)

Prof. Google says: Clearly this guy, and possibly this piece, or his book of 2005. Or Climate Change: A Multidisciplinary Approach (Second Edition) By William James Burroughs, Cambridge University Press, 2007, etc. The text has been in the article for ages. Johnbod (talk) 14:24, 8 March 2013 (UTC)

Ok it was all a copyvio from this, which I have rewritten & refed. Johnbod (talk) 15:01, 8 March 2013 (UTC)

"Global" nature of the LIA

There is a mini edit-war about "global cooling" in the first sentence. Since the extend and effect of "the" little ice age varied very much depending on location, I feel that this term is misleading. There probably was an underlying global phenomenon, but cooling was neither synchronous nor universal over the globe, as obvious from the recent literature. --Stephan Schulz (talk) 07:28, 22 November 2012 (UTC)

Agreed. There is a more general problem with Junaji, who seems to turn up, make the same edits, get reverted, and never discuss anything. I was just going to leave a message about this on his talk page, but I see various people have done so today William M. Connolley (talk) 08:32, 22 November 2012 (UTC)

Just came across a 'new' paper by Rhodes et al: "Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica from a coastal ice core record". Clim. Past, 8, 1223–1238, 2012. It looks very detailed and they conclude "The MES stable isotope record suggests that the Ross Sea region experienced 1.6 ± 1.4◦C cooler average temperatures during the LIA in comparison to the last 150 yr". Should this be added to the Antartica section? — Preceding unsigned comment added by Mbcannell (talk • contribs) 16:27, 11 March 2013 (UTC)

Propaganda

This article has become nothing more than a propaganda piece for global warming proponents. It is time to starts a NEW wiki system without the possibility of zealot controllists revising history every time they feel like pushing a social engineering scheme. — Preceding unsigned comment added by 168.208.215.221 (talk) 12:31, 13 March 2013 (UTC)

Perhaps you prefer the Conservapedia version? William M. Connolley (talk) 14:20, 13 March 2013 (UTC)

Unfortunately I have to agree with user 168.208.215.221 especially with regards to the paragraph "possible causes of little ice age ->Decreased human populations". The population decreased because of the ice age and it is clearly stated in the article that although there is controversy about the exact point in time it started early indicators are from 1250 CE onward. People in Europe began to die off in 1350 due to plague which was facilitated by malnutrition. The events in the Americas are even later and there are very few reliable data on population density anyway. So the editor or "scientists" who make that claim confuse cause and effect. The correlation between solar activity and average temperature is so high that the generally agreed on scientific consensus blames the little ice age on the decline in solar activity. There may be other causes like volcanoes which contributed to the global cooling but the primary cause is the decreased solar output over a period of several hundreds of years.

How does one get banned from a science blog? I have to ask. — Preceding unsigned comment added by 168.208.215.221 (talk) 17:50, 13 March 2013 (UTC)

No idea, I don't know anyone who is. Unlike WUWT, who regularly bans people who embarass him William M. Connolley (talk) 17:55, 13 March 2013 (UTC)

You seem to be holding a grudge... or do you need traffic on your blog that desperately?

Asia?

Any records of strange weather or crop failures in India, China and the Middle East? 188.221.129.72 (talk) 19:54, 17 September 2011 (UTC)

There should be a whole section on it. The fall of Ming Dynasty was proposed to be at least partially caused by Little Ice Age. 152.2.14.92 (talk) 19:11, 31 January 2013 (UTC)

In the section on North America and Europe, there's a paragraph containing references to North Africa and China. Should that be moved to a separate section, perhaps "Other Northern Hemisphere" or something like that? Crymerci (talk) 03:57, 16 March 2013 (UTC)

Early European settlers reported in 1607-1608 on Lake Superior?

I'm taking issue with this statement: "In North America, the early European settlers reported exceptionally severe winters. For example, in 1607-1608, ice persisted on Lake Superior until June." The first European credited with the discovery of Lake Superior was Étienne Brûlé roughly around 1618 - ten years before the above statement. Quebec was only founded in 1608. I would like to see an exact quote of: Lamb, Hubert H. (1995). "The little ice age". Climate, history and the modern world. London: Routledge. pp. 211–241. ISBN 0-415-12734-3, which was used as the source. Dinkytown talk 07:17, 3 December 2013 (UTC)

To User:Dinkytown: Lamb did write that – "And Samuel Champlain, the founder of Quebec, found bearing ice on the edges of Lake Superior in June 1608." [16]. It’s in quite a few other books as well. [17]. But it is contradicted by the many other sources saying Brûlé was the first European there, dates vary, but sometime in the late 1610s or early 1620s. [18]. I’d support taking the Lake Superior example out. Good catch. Novickas (talk) 17:44, 3 December 2013 (UTC)

I can only find one source of the book online and it has major gaps in pages (especially between pages 211-241 which would presumably include the source for the sentence). I would rather the tag stay until we can verify what the source ACTUALLY says, but I'm not hard bent either way. Ckruschke (talk) 18:04, 3 December 2013 (UTC)Ckruschke

Sorry to hear that you can't see it thru the Google book link provided above- they do some strange access juggling sometimes. Maybe you could confirm it for yourself by using the Amazon Look Inside feature, its link for this book is [[19]]. You can't permalink to a search result, but once you're at that specific Look Inside page, you can put in the search term 1608. It returns only 1 result page, showing the sentence quoted above that begins with "And Samuel Champlain, the founder..." It's on page 220. Novickas (talk) 18:48, 3 December 2013 (UTC)

Oh - ok - I'm sorry, I misread your post. Couldn't we rewrite the sentence to say:

In North America, Hubert H. Lamb reports in his early work "Climate, History, and the Modern World" that Samuel Champlain noted bearing ice along the edges of Lake Superior in June 1608. However, later historians question whether Champlain even reached Lake Superior by 1608 so this evidence may be anecdotal.

That sounds kind of weird, but my concern is that someone will come back and reinsert this based upon the weight Lamb's book brings to the subject. I'm not sold either way though and am ok with the deletion or whatever you guys decide. Ckruschke (talk) 19:20, 3 December 2013 (UTC)Ckruschke

Hi User:Novickas, Hi User:Ckruschke - thank you for your thoughts on this matter. I believe that there are several things wrong with this statement. First, having ice along the shore of Lake Superior, is like having snow in Minnesota (where I'm from) - obvious... The lake also completely freezes over once every ten years or so, so having ice on the shore would be quite normal. In fact, there are often 'ice boulders' the size of a small house on the shore from the wind pushing it around. Second, I didn't even know that Champlain even made it out to Lake Superior, so this is something that is new to me. According to Lamb, Champlain's discovery of Lake Superior pre-dates Brûlé. I'm curious as to where Lamb got this source. I'm thinking that because the above statement is not a good example (walking from Manhattan to Staten Island is a much better one), and that there seams to be a conflict of who 'discovered' Lake Superior between Champlain and Brûlé that it might not be a good idea to remove this statement all together, until the Champlain source can be brought to light. I would love to use it, but this might be a source of conflict between the two would-be-first explorers. Take care.... Dinkytown talk 21:30, 3 December 2013 (UTC)

Oh, BTW - thanks to both of you for citing the sources so easily - :) Dinkytown talk 21:31, 3 December 2013 (UTC)

Good heavens, what a civilized discussion :) A couple of thoughts. We don't have any reliable sources saying 'Lamb was wrong about Champlain seeing ice on Lake Superior in 1608'; just us Wikipedia editors. So maybe we could leave it in and attribute the statement to Lamb, but more briefly, like 'According to Hubert Lamb, Samuel Champlain reported ice along the shores of Lake Superior in June 1608.'(reference) Leaving out the details of the book title and date, which are in the reference. We don't know how Lamb concluded this; we could speculate that Brule reported it in some journal and then maybe a digit got transposed in Lamb's book somewhere along the line (changing 1618 to 1608)? Might be worth a note in the Lake Superior article. BTW, I live near Lake Middling and have only visited Superior in late summer and midwinter, so have no idea whether ice on that lake in June is unusual or not. Novickas (talk) 23:01, 3 December 2013 (UTC)

Dinkytown - I think the point here was "bearing ice in June". I am also from MN (which makes me laugh now that I didn't put 2&2 together on your name - spent many great times down in Dinkytown) and of course you get ice in the winter, but even in Duluth, MN & Thunder Bay, ONT (where I spent the coldest July in my life) you don't get ice in the summer and certainly not bearing ice.

Novickas - I like your suggested sentence and agree we don't need to talk about the book in the sentence. Either that or completely delete it like Dinkytown suggests. Deleting it would probably be easier. I also like putting something in the Lake Superior article. I'll see if I can find a good place for a copy paste of your sentence above. My 2 cents. Ckruschke (talk) 13:34, 4 December 2013 (UTC)Ckruschke

cold

London was in the Little Ice age had winters 15F degrees colder than they are today by average — Preceding unsigned comment added by Jimbowellls (talk • contribs) 19:19, 10 February 2015 (UTC)

Jimbowells has been indefinitely blocked for vandalism and such. - SummerPhD (talk) 00:48, 13 February 2015 (UTC)

21st Century mini-ice age conjecture

Apparently we will all put our heads in the sand and deny the existence of this theory. Two of you have struck any link to this article in the Little Ice Age article. Apparently you don't know how to "compare and contrast," distinguish or use a metaphor. This is your religious orthodoxy. Not mine. Plausibly, this could easily be included and would be a good fit in the Little Ice Age#Solar activity or Little Ice Age#Orbital cycles sections. I would think that readers should be apprised of its existence, and make up their minds after they examine the literature. The article as presently written is not WP:POV. I do not think that censorship, suppression or heresy analysis is appropriate. The matters should be freely discussed and vetted. 7&6=thirteen (☎) 22:10, 1 March 2015 (UTC)

Discuss edits please, not editors. You have mischaracterized my revert. NewsAndEventsGuy (talk) 22:49, 1 March 2015 (UTC)

I did not mention any editor(s). If the shoe fits... Happy editing. 7&6=thirteen (☎) 01:30, 2 March 2015 (UTC)

I am discussing edits. To be clear, I am not saying that the theory is correct. But I am saying that it exists as a theory, needs to be discussed and considered. And that includes appropriate links within this article, to inform and empower readers so they can find the other related article. I tried the "See also" section and that was removed. I tried Little Ice Age#Solar activity and that was removed. I am suggesting Little Ice Age#Orbital cycles. All I was trying to do was put in a link, and leave the article without regurgitating the material already in 21st Century mini-ice age conjecture.

Rather than WP:Edit war with you over that, I call that to your attention and hope that the two of you figure it out. 7&6=thirteen (☎) 13:55, 2 March 2015 (UTC)

I am saying no, sorry, its still not worth linking to. There's no need for impatience. If the article you want to link to turns into something worth having, then fine we can link to it. If it remains junk, we can AFD it William M. Connolley (talk) 16:25, 2 March 2015 (UTC)

It rather is not "the theory", rather it seems like a fringe conjecture. With only references from the Daily Mail, The Times of India, a German newspaper, and a blog - and based on a Russian "Science and Public Policy Institute" report it should not be linked. Unless solid science sources discuss it -- it simply deserves afd. Vsmith (talk) 18:00, 2 March 2015 (UTC)

Inappropriate data smoothing

Thoughts on this analysis?

"While the idea that Europe experienced a Little Ice Age is widespread, its statistical basis is at best exiguous, and appears to stem from inappropriate efforts to smooth data that are actually random. At the same time, most of the anecdotal evidence admits more simple explanations than climate change."Shtove (talk) 19:46, 28 March 2015 (UTC)

Might be worth adding, reffing to their papers rather than (or as well as) this blog post. These are primary studies - ideally we'd use secondary academic sources which may not exist yet. Johnbod (talk) 13:31, 28 March 2015 (UTC)

Yes. Can't do anything myself - touchy subject!Shtove (talk) 19:46, 28 March 2015 (UTC)

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De-politicize article a little?

I was interested in information on the little ice age.

Instead of quality information just saying how much colder it was, that information is buried deep in the article.

And instead of a chart showing average temperature now to the present in degrees ...

... it has an unfriendly chart showing temperature variance which doesn't mean anything to me or probably most people.

Is there a particular reason this article can't have the average temperature and a decent chart? — Preceding unsigned comment added by 65.60.224.195 (talk) 08:48, 30 August 2015 (UTC)

The chart at the top needs to be changed

The medieval warming period had temperatures warmer or the same as current temps. The chart shows some kind of wild variation from consensus data for the modern period. The source seems to be an interest group called "Berkeley Earth" — Preceding unsigned comment added by 24.207.135.183 (talk) 08:48, 19 October 2015 (UTC)

Nope, overall you're wrong. All the BEST. . . dave souza, talk 10:35, 19 October 2015 (UTC)

The chart is complete fiction. Medieval and Roman warm periods have both been documented in the Greenland Ice Cores as being 2°C warmer than present. This is acknowledged in science by everyone except Michael Mann for obvious reasons (it invalidates his fictional "hockey stick"). 198.51.104.134 (talk) 17:24, 4 April 2016 (UTC)

Naming

Recently, a theory on another Little Ice Age has been proposed in a different period - the Late Antique Little Ice Age (540s-650s). Shall we perhaps consider a more specific title to this article as well to distinct from Late Antique and other "little ice ages" (including the Bronze Age Cooling)?GreyShark (dibra) 05:47, 11 September 2016 (UTC)

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“Frost fairs, sunspots and the Little Ice Age ”

Frost fairs, sunspots and the Little Ice Age

Mike Lockwood Mat Owens Ed Hawkins Gareth S Jones Ilya Usoskin

Astronomy & Geophysics, Volume 58, Issue 2, 1 April 2017, Pages 2.17–2.23, [https://doi.org/10.1093/astrogeo/atx057

[20] Doug Weller talk 20:01, 6 January 2018 (UTC)

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Bad link *Corrected formatting/usage for http://waiscores.dri.edu/MajorFindings/MayewskiRes.html 7&6=thirteen (☎) 03:42, 22 January 2018 (UTC)

New edits

Hello everyone, I just added a subsection within the Europe section titled "cultural responses" where I discussed scapegoating and other general reactions to the Little Ice Age. I feel that it is important to discuss how particular groups were targeted during this time. Let me know what you think and if there's anything I could expand on/clarify. Maggiep (talk) 16:47, 6 March 2018 (UTC)

Remove the first figure

I propose to remove the first figure, does everyone agree? Dr. Universe (talk) 07:34, 24 February 2019 (UTC)

Errm, no William M. Connolley (talk) 10:08, 24 February 2019 (UTC)

The Pages 2k consortium will produce a new GMST timeseries in the next couple of weeks. I'll make a new Figure with that data. For now, let's keep it. Femke Nijsse (talk) 11:47, 18 March 2019 (UTC)

Another paper

https://www.swsc-journal.org/articles/swsc/abs/2017/01/swsc170014/swsc170014.html "The Maunder minimum and the Little Ice Age: an update from recent reconstructions and climate simulations" William M. Connolley (talk) 09:47, 10 March 2021 (UTC)

Ok - so what are you suggesting we edit on the page? Ckruschke (talk) 18:14, 10 March 2021 (UTC)Ckruschke

Volcanoes

Should 1465_mystery_eruption be mentioned? Skintigh (talk) 15:45, 26 May 2021 (UTC)

Decreased human populations

It has been estimated that approximately 11% of the world's population was killed either during or immediately after the Mongol invasions of the 13th century Destruction_under_the_Mongol_Empire

Should that be discussed more in the section on decreased human populations? I realize this isn't as significant as the black death toll, but the fact it occurred before the beginning of the little ice age suggests it could be a cause. If humans had already increased the levels of CO2, and had already influenced the climate, an 11% decrease in carbon emissions (plus reforestation plus a drop in agriculture) could take decades to lower the global levels and start cooling. It appears there was a 2PPM global drop in CO2 levels in the first half of the 13 century.

This drop could have then been reinforced by (and perhaps exacerbated and even helped spread) the black death. Skintigh (talk) 15:40, 26 May 2021 (UTC)

Skintigh, you need a reliable source that claims that the deaths due to the Mongol invasions might have been a contributing factor to the Little Ice Age. Same for your next section on a volcano eruption. See WP:OR. Schazjmd (talk) 16:16, 26 May 2021 (UTC)

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Maggiep.

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Mississippian culture

Shouldn't the Mississippian culture in North America be mentioned in this article? Extended droughts caused by the Little Ice Age appear to have caused the depopulation of numerous large settlements by around 1450, a fact that is mentioned in articles such as this one. 204.11.186.190 (talk) 16:14, 2 November 2022 (UTC)

Agricultural counter-revolution

Brian Fagan describes a dramatic drop-off in agriculture in the late 17th century.

I noted that the 17th century is generally regarded as time of the modern agricultural revolution in the Netherlands and Britain, with yields per land and labor reaching unprecedented level and an enormous amount of evidence indicate flourishing agriculture of the time.

The note was reverted as an "overenthusiastic personal opinion."

The modern "agricultural revolution," dated to the 17th century, is mentioned in the 1960s. I was born in 1972 (birth certificate can be presented). It cannot be my personal opinion. I have alibi.--Maxaxa (talk) 21:55, 30 March 2023 (UTC)

I thought the edit summary was apt. Before dismissing Fagan out of hand, critics should read him a bit more carefully. He actually does note that improved agricultural practices in England helped to overcome much of the climate adversities, while in France, the lack of progress resulted in continued periodic food shortages. Wikipedia has done a less-than-adequate job of summarizing the impacts, making it sound like 500 years of unremitting famine and hardship across Europe. Fagan presents a more nuanced picture where poor harvests and other weather-related impacts were episodic and regionalized.Glendoremus (talk) 00:55, 31 March 2023 (UTC)

This version would be better in the article. But much discrepancy with the history of agriculture would still remain. England did not just overcome the climate adversities, the yields reached historical high. Among all English agricultural improvements of the 17th century, there was not a single one untried before, yet the Agricultural Revolution did not happen until the 17th century. The LIA climate favored agriculture at least in Britain and the Netherlands and in the rest of Europe did not damage it more than during the Medieval Warm Period. Maxaxa (talk) 23:08, 31 March 2023 (UTC)

You cannot use a pop-sci book as a source for An enormous amount of evidence indicate flourishing agriculture of the time but Fagan successfully overcame all this evidence to push his argument through. If Fagan actually wrote scientific papers, that have survived and are respected, that would be different William M. Connolley (talk) 08:26, 31 March 2023 (UTC)

It is the argument of Fagan which is problematic. Maxaxa (talk) 23:12, 31 March 2023 (UTC)

Ah, I agree. You are suffering from ambiguity. I took your but Fagan successfully overcame all this evidence to push his argument through to mean but Fagan successfully overcame all this evidence (in the sense of, producing better counter-evidence) to push his argument through (into being accepted). If you meant something else, you should clarify William M. Connolley (talk) 17:59, 1 April 2023 (UTC)

References