Talk:Little Ice Age

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Contents 1 Global vs local paragraph 2 Phrasing of dates 3 Classification of links 4 Glob/reg ref 5 Orbital cycles 6 end of lia / recovery 7 LIA artwork 8 Rm graph 9 Why MID-14th Century? 10 Copyvio 11 NPOV of IPCC quote in intro section 12 Inuit in Scotland? 13 Sydney 14 "There is a wide consensus among climate scientists" 14.1 Assertions 15 Oort Minimum? Wolf Minimum? 16 Are you certain that this is written sufficiently confusingly? Could this be a little less well edited? 17 End of LIA reversions 18 Eds Eds

[edit] Global vs local paragraph

This article includes discussion of global warming which is off the topic. Would it be better if the second paragraph were moved to the global warming page? Robert McFaul 00:28, 28 Feb 2004 (UTC)

(William M. Connolley 11:22, 2004 Feb 28 (UTC)) Do you mean:

It was initially assumed that the LIA was a global phenomenon. It is now less clear that this is true [1]; for example the reconstruction of temperature in the northern hemisphere over the last 1000 years [2] does not show a pronounced period of cooling. See Medieval Warm Period for more on this. The IPCC describes the LIA as a modest cooling of the Northern Hemisphere during this period of less than 1°C.

If you do, I don't understand your comment. This is pure LIA.

I was referring to making the article follow the form - In European history ... the LIA ... etc. For discussion of global rather than regional climate changes, see Global Warming.

This alternative I am suggesting is to describe the LIA as a European History event and refer global climate change interested readers to the Global Warming page. Robert McFaul 02:57, 2 Mar 2004 (UTC)

(William M. Connolley 09:36, 2004 Mar 2 (UTC)) I advise against it. For one thing, there is the politics: for some people it is important for the LIA to be global, and if you go and describe it as pure European you will annoy them a lot. For another, whether it was global or not is one of the LIA's interesting questions and belongs (I think) with the LIA page.

OK, I will accept your advice. Robert McFaul 22:02, 3 Mar 2004 (UTC)

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[edit] Phrasing of dates

(SEWilco 04:01, 21 May 2004 (UTC)) I used the other phrasing, with 14th century, to make Wiki Preferences date handling easier. If "century" is outside the brackets, Wiki coders will have to work harder to detect and properly display that. I recognize the century is unlikely to change unless Wiki includes display using other calendars.

• mid-14th through mid-19th centuries

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[edit] Classification of links

(SEWilco 04:12, 21 May 2004 (UTC)) I thought it was appropriate to group references based on POV (the labels were from the hosting site's "About" descriptions). Similar to how pages about organizations have those grouped based upon their focus. Or perhaps the hosting organization should simply be present as a label, being linked to their About page, just as a study from a University site might have a link to that organization.

(William M. Connolley 08:41, 2004 May 21 (UTC)) I disagree. Labelling the IPCCs discussion of LIA/MWP under "risk of human cl ch" makes little sense. OTOH as far as I'm concerned the greening-the-earth-soc folk are POV-pushers, so if you want to label them as Skepticism concerning catastrophe I won't object again.

(SEWilco 15:40, 21 May 2004 (UTC)) Both phrases are POV from the definition of the organizations. I'll let readers interpret the organizations themselves.

(SEWilco 04:29, 21 May 2004 (UTC)) Apparently someone read two of the linked studies, and added summaries or notes. Other readers are invited to do that. The current links are a few which seemed particularly relevant, particularly another which shows little LIA signature.

(William M. Connolley 08:41, 2004 May 21 (UTC)) I added the notes. The problem is there are countless LIA studies around, you can only make a random selection of a few to link to.

[edit] Glob/reg ref

(WMC) For SEW: Google Groups search for "little ice age" "climatic change" connolley

(SEWilco 15:40, 21 May 2004 (UTC)) You forgot the preceding paragraph, which indicates interest in the MWP. There seems to be agreement that the LWP was a global decline in temperatures associated with the Maunder Minimum and punctuated by volcanic activity. The MWP is more controversial, but in whether the higher temperatures were globally synchronous or regionally scattered (and corresponding colder regions).

"We come back to our original question: was there a "Medieval Warm Period",

and if so, where and when? Some of the evidence compiled here and in the 12 articles of this special volume suggests that the time interval known as the MWP from the ninth to perhaps the mid fifteenth century AD may have been associated with warmer conditions than those prevailing over most of the next 5 centuries (including the 20 C), at least during some seasons of the year in some regions."

(William M. Connolley 17:31, 2004 May 21 (UTC)) I really don't understand why you persist in this. "The generalised behaviour of the global climate of the last millenium as a Medieval Warm Period followed by a Little Ice Age, each of one or more centuries long and global in extent, *is no longer suppported by the available evidence*." Thats from a paper published in 1994. So please stop the rubbish about IPCC changing its mind in 2001. You need to read more scientific papers and fewer right wing websites.

[edit] Orbital cycles

I've removed the stuff about the Milankovitch cycles as a reason for the Little Ice Age. The explanation an anon editor had added was:

The Earth's axis of rotation slowly changes through time, much as a quickly spinning child's top will slowly precess. The direction the axis is pointing relative to the sun defines the Earth's seasons (See Milankovitch_cycles). The rate of axial precession changes the dates of the seasons by one day per 58 years. The Earth's orbit around the sun is somewhat elliptical, meaning that at some points during the year the Earth is closer to the sun than at other times. In about the year 1250 AD, each European summer was coming when the Earth's north pole was tilted toward the sun when the Earth was farthest from the sun, causing cooler than average summer temperatures in the northern hemisphere.

This is hopelessly confused. 1 day per 58 years seems about right, but summer on the Northern hemisphere is always when the North Pole is tilted towards the sun. It's just that this happens every some 21000 years when the Earth is at its aphelion, which results in about a 6% decrease in insolation compared to when it happens at the perihelion. And anyway, take about 750 years and divide by 58: you'd get a difference of some 12 days. The Milankovitch cycle is just too long to explain such relatively short phenomena as the Little Ice Age.

Lupo 13:48, 20 Jul 2004 (UTC)

[edit] end of lia / recovery

(William M. Connolley 11:03, 29 Aug 2004 (UTC)) If the lia ended in 1850, how can we still be recovering from it?

Maybe we're still warming back up to MWP or HTM temperatures? (SEWilco 06:20, 18 May 2005 (UTC))

(William M. Connolley 16:28, 18 May 2005 (UTC)) Since we're already clearly above MWP temperatures, that would seem rather unlikely.

I'm sure you have your sources. (SEWilco 18:28, 18 May 2005 (UTC))

[edit] LIA artwork

There was a flurry of cold-scene paintings during the LIA. Anyone have more precise timings? So far all I've found was mention of there being a transition between two painting styles during that period. (SEWilco 06:19, 18 May 2005 (UTC))

It is requested that an image be included in this article to improve its quality, if possible. This image request is for a gallery of winter depictions.

I'd like a gallery of these winter pictures, now that there is a section. --84.20.17.84 15:59, 2 February 2007 (UTC)

[edit] Rm graph

See MWP. William M. Connolley 09:55:23, 2005-09-03 (UTC).

[edit] Why MID-14th Century?

I'm curious why the LIA is regarded as starting around 1350 and the Great Famine of 1316-17 being part of the MWP. Brian Fagan (The Little Ice Age, 2000, Basic Books) regards the rains of 1315 to be the beginning of the LIA. I'd imagine that there are probably scholars who disagree with him, but I'd like to see some discussion of it or I'll be tempted to edit. Thanks! Jberkus 04:52, 9 September 2005 (UTC)

The dates are somwhat arbitrary. But shifting them because you "know" that famines only happen during the LIA is distinctly dodgy. At the very least we need to make sure that the LIA and MWP don't overlap... ideally there would be some sepearation between them. William M. Connolley 18:38:43, 2005-09-09 (UTC).

William: It's not because of the famine; it's because of the rains. In 1315, the system of high and low pressure zones near Europe (known as the North Atlantic Oscillation) inverted unusually quickly and severely, resulting in three years of rainy, cold summers (which led to the Great Famine). The average temperature in Northern Europe dropped for about 5 years to levels lower than it had been in 400 years. While the warm climate did recover somewhat in the 1330's, it didn't recover to nearly the peak levels of the WMP, and by about 1340 was dropping again and did not recover until 1850 (all data is from Fagan).

So, at most, the era 1310 to 1350 is a "transitional period". It's certainly not part of the WMP. Since you don't seem to have objections, I'm going to modify this article and the WMP article to suit. Jberkus 04:50, 11 September 2005 (UTC)

The average temperature in Northern Europe dropped for about 5 years to levels lower than it had been in 400 years - source?

As I say above, all data is from Fagan. Unfortunately, he doesn't have a citation for the median North Atlantic temperature chart that I can find (which is annoying, he has sources for everything else). Jberkus 20:18, 11 September 2005 (UTC)

In general, the question of the dates for the LIA needs to be sorted out - either find what is generally agreed, or find that no-one generally agrees. Jones and Bradley (climate since 1500; p652) "evidence for a period of protracted cool temperatures during the so-called lia during the 16th to 19th centuries does not appear that convincing; the best documented and most widespread cool periods occurred during the 17th and 19th centuries". They are talking about europe, not globally. Later (sect 33.5) discusses what the LIA actaully means. Porter (1986) uses 1250-1920; Lamb (1977) uses 1550-1850, but mostly 1550-1700; Grove (1988) "seems to concur with Lamb". William M. Connolley 10:37:28, 2005-09-11 (UTC)

Yes, it depends on whether you're treating the LIA as a predominantly Atlantic phenominon (in which case you could push dates back as far as 1300) or whether you're making a case for a global context (in which case temperatures don't dip away from the Atlantic until the 16th century). I think that we should probably expand the section on "Beginning of the LIA" to be "Dates of the LIA" and explain the vagueness and lack of consensus on the definition of the LIA. Be my guest. Jberkus 20:18, 11 September 2005 (UTC)

Oh, also I find that most historians using the 1250 date are looking at the LIA as dating from the decline of the Greenland and Iceland colonies due to shorter summers and increased Atlantic ice. According to Fagan, however, this was a specifically localized event (to the Greenland area) caused by fluctuations in the NAO, and Western Europe was still enjoying long warm summers through the 1280's. Jberkus 20:22, 11 September 2005 (UTC)

OK, I've changed the section to Dates of the Little Ice Age as discussed. I'm a little uncertain how to cite my sources; the 1st half is Fagan (a non-web reference) and the 2nd half is a synthesis of all of the sources quoted above. Could a more experienced Wikipedia editor help me out here? Jberkus 03:58, 13 September 2005 (UTC)

I'll have a look. BTW, be cautious about leaning too heavily one any one source, especially a popular book (as I assume Fagan is). Refs: if Fagan is any good, he will ref his various statements to specific papers, so you can ref those. Finally, shorter summers and expanding glaciers are recorded almost worldwide sounds distinctly implausible: what does he source that to? William M. Connolley 09:02, 13 September 2005 (UTC).

The worldwide stuff? Mostly Lamb, apparently. It's a popular book so it's not heavily annotated. He specifically cites expanding glaciers in China, the Anders, New Zealand and Alaska as well as Europe. Where the data on New Zealand is from I can't imagine.

Your revisions based on wider reading are very welcome. Jberkus 04:53, 14 September 2005 (UTC)

[edit] Copyvio

This paragraph appears to be a verbatim copy from its cited source:

In Ethiopia and Mauritania, permanent snow was reported on mountain peaks at levels where it does not occur today. Timbuktu, an important city on the trans-Saharan caravan route, was flooded at least 13 times by the Niger River; there are no records of similar flooding before or since. In China, warm weather crops, such as oranges, were abandoned in Jiangxi Province, where they had been grown for centuries. In North America, the early European settlers also reported exceptionally severe winters. For example, in 1607-8 ice persisted on Lake Superior until June [10].

It's copied from [1], which is its cited reference. This document appears to be a government work and is therefore (probably?)in the public domain, but should we really be "borrowing" paragraphs from any other work verbatim? JRP 13:04, 18 April 2006 (UTC)

[edit] NPOV of IPCC quote in intro section

I would like to point out that the quote from the IPCC report describing the LIA as "a modest cooling of the Northern Hemisphere during this period of less than 1°C" omits a phrase that is potentially significant. The full sentence reads, "However, 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." (emphasis added) The omission of the final phrase creates the misleading impression that the LIA was an insignificant blip on the climatological record. Howvwer, the temperature change is much more pronounced when viewed relative to the MWP. According to the History Channel's "Little Ice Age: Big Chill", the temperature drop from the height of the MWP to the depth of the LIA was a whopping 4-7°C! When viewed in this context, the "less than 1°C" shift from LIA to today suggests that we are still in the LIA. Even using the approx. 4°C increase since the late 1800's stated by the History Channel, we're only just getting back to the most modest estimate of the temperatures from the MWP.

But this is nonsense. No-one (not even the septics) thinks the MWP was 7 oC warmer than the LIA. See temperature record of the past 1000 years for some graphs. The MWP was probably cooler than late 20th C. William M. Connolley 21:29, 3 May 2006 (UTC)

Granted, 7°C is the most extreme estimate, but it wouldn't have been in the program if nobody believed it. If you check out footnote #7 in Medieval Warm Period, you'll see that the US Geologic Survey has presented "evidence for rapid (<100 yr) shifts of ~2-4ºC in Chesapeake Bay (CB) temperature".

But this is a different thing entirely! We were talking about hemispheric averages - not regional changes. And if your best source for 7 oC is 2-4 oC, you're out by a lot. William M. Connolley 20:21, 4 May 2006 (UTC)

No, it's not "a different thing entirely." Hemispheric averages are just a compilation of numerous regional averages. If regional themperatures drop, they'll bring down the hemispheric average.

Of course its entirely different! The smaller the scale you go to, the larger the extremes. Averaging smooths them out. Plus, there is a natural energy-conservation argument on global/hemispheric scales that doesn't apply locally. William M. Connolley 15:19, 5 May 2006 (UTC)

Averaging obscures the fact that climatological phenomena move. If a cooling pattern begins in Europe, then spreads outward into the rest of the Northern Hemisphere before finally reaching the south, Europe could easily be on its way to recovering before southern Africa (for example) has even begun to feel any effects. Then a global cooling event ends up looking insignificant when worldwide (or even hemispheric) averages are used simply because it affected the world progressively rather than everywhere at the same time.

D.R. Legates from the National Center for Policy Analysis estimates that "the temperature difference between the Medieval Warm Period and the Little Ice Age is about 1.2°C" ([2])

Ahem. So now you're down from 7 to 2-4 to 1.2. But if you look at the nice graph on Temperature_record_of_the_past_1000_years you'll see 0.8 is about the max. William M. Connolley 20:21, 4 May 2006 (UTC)

You're clearly missing my point. I never argued that any one estimate was correct, only that there exists considerable disagreement over the severeity of the temperature changes and that the IPCC reference and the graphs are unfairly biased in favor of the minimalist view.

You can argue about the magnitude, but quoting completely implausible figures (7 oC!!!) from a non-science source doesn't help you. The IPCC, of course, is not biased. You could try reading it, perhaps. William M. Connolley 15:19, 5 May 2006 (UTC)

Implausible why? Because you say so? Although the History Channel is a non-science source, it beats the no-source-at-all you use to bash it. And I wouldn't call the IPCC an unbiased source. On their "Activiites" page they state "the major activity of the IPCC is to prepare in regular intervals comprehensive and up-to-date assessments of policy-relevant scientific, technical and socio-economic information relevant for the understanding of human induced climate change." That sounds like a very biased presupposition that climate change must be human-induced and any evidence that it might be part of a natural cycle would be a direct threat to them. Maybe that's why they don't even mention the existence of dissenting opinions in their Climate Change 2001 report.

and critiques the "apples-to-oranges " methods used by researchers to obtain lower estimates. And PBS's "Scientific American Frontiers" reports that during the MWP "temperatures were 2 to 3 degrees Celsius higher than they are today" ([3])(emphasis added). So, your graphs are by no means the only, or even the definitive, models of temperature variation.

You can't use PBS as a definitive source! Science trumps public broadcasting, of course. Notice that even they are only saying that for *European* Ts, and they are probably wrong about that. And they are using the long-discarded IPCC '90 schematic (note the lack of y-axis labels?). William M. Connolley 20:21, 4 May 2006 (UTC)

In case you didn't pick it up from the show's title, PBS's source for this was Scientific American, a highly respected publication. As soon as I get a chance I'll get you some references straight from the source.

If your source is Sci Am, then quote that, not a second hand source. And of course Sci Am isn't a primary source either. And I notice you evade the fact that it was European only... and the discarded graph... and... William M. Connolley 15:19, 5 May 2006 (UTC)

They are only discussing European temps, but when you combine that with the Chesapeake Bay data and the IPCC report's own material on the Sargasso Sea it becomes clear that these effects cover an area too large to be reasonably considered a localized event. While on the subject of evasions, I noticed that you haven't had anything to say about the NCPA's refutation of the methods used by those trying to downplay the severity of the LIA.

As far as the issue of dates goes, it would be advisable to keep in mind that one theory for the cause of the LIA is a breakdown of the North Atlantic Conveyor, the section of the thermohaline circulation system of ocean currents that carry warm water from equatorial regions toward the polar areas of the North Atlantic. Europe, being the prime beneficiary of the NAC, would naturally feel the effects of this breakdown first. It is also logical that, if the breakdown persisted, the cooling effect would next spread to rest of the Northern Hemisphere, with the Southern Hemisphere affected last, if at all. This scenario has also been theorized for similar previous cooling periods during the Younger Dryas and the Older Dryas. This apparent pattern of warming and cooling strongly suggests (to me at least) that today's "Global Warming" is just a part of the natural climatological cycle and not human-caused.

Um, very nice, please remember WP:NOR. Now if you can find a reputable source for what you're saying, thats another matter William M. Connolley 21:29, 3 May 2006 (UTC)

See the above-mentioned footnote #7 and the Younger Dryas entry. Also:

[4] [5] [6]

Again, you haven't had anything to say here. Of course, as an Antarctic climate modeler and a member of the Green Party (I checked out your blogs & your webpage), you would stand to lose significantly if people stopped being scared of the "Global Warming" boogeyman and started viewing it as a part of the natural cycle for which humans are not to blame and can't do anything about. I guess a certain lack of impartiality is to be expected here.

Erm...so being a climate modeller leads to partiality? Well, I guess actually understanding a topic does tend to bias one against nonsense, but we generally consider that kind of "bias" a blessing. --Stephan Schulz 20:32, 5 May 2006 (UTC)

No being a climate modeller (and, thus, having the continuation of his career dependant on continued public (1) concern about climate change and (2) belief that we can somehow do something about it) leads to a seious potential for conflict of interest. The way he attempts shout down & belittle dissenting viewpoints without providing any evidence of why they're wrong, while avoiding syaing anything about evidence that has been presented refuting his viewpoint is what makes him impartial. I don't claim to have all the answers (or even any of them) to the climate change question. I just don't think it's right that Mr. Connolley is trying to convince people that there is a consensus on the subject (he's even publiced articles to that effect, as you can see from his Wikipedia page here: William Connolley ), when there clearly is not one.

So indeed, by your reasoning the opinion of anybody who understands the topic is suspect...after all, their "career depends on continued public concern..." And indeed, there is a broad and strong scientific consensus about anthropogenic global warming. The serious scientists do quibble about details, not about the basic facts. Since we're on the LIA page: Even when von Storch had just published his paper that saw a LIA conflicting with the Mann et al. reconstruction, he still publically accepted the fact of anthropogenic global warming and the need for curbing CO2 emissions. Since then, two serious errors in his paper have been discovered. If they are fixed, the results are well within the range of uncertainty of Mann's reconstruction. Von Storch has acknowledged this, if not as publically as some would have wished. As another example, Christy, who for a long time expressed scepticism based on the satellite data, has come around and has helped draft the AGU position statement on climate change. Even Singer does not deny the warming any more (although he has moved the the "natural causes" camp). --Stephan Schulz 18:40, 6 May 2006 (UTC)

No, understanding a subject doesn't -- in and of itself -- make one's opinion suspect; however, when someone who has a vested interest in seeing a particular opinion favored over another is in a position to control dissemination of information concerning the subject in question (such as being an administrator here, as Mr. Connolley is), his/her objectivity should be closely scrutinized. Otherwise we run the risk of creating the same "I'm an authority -- don't question me" mentality that currently plagues the U.S. government. I think Swiss philosopher Andre Gide put it best: "Believe those who are seeking the truth. Doubt those who find it." And if there is, as you put it " broad and strong scientific consensus about anthropogenic global warming," then why is it that Wikipedia's entry on the Global warming controversy has more entries in the sections on "Opponents of the global warming theory" and "Points made by Opponents..." than it does for supporters & their points? (Incidentally, the talk page of that entry also contains several by Mr. Connolley denouncing anti-GW evidence without presenting any hard evidence of his own to back up his claims. If you look at the global warming page of skepticism.net [7], particularly the articles in the section titled "The Scientific Controversy" you'll see that there isn't even a consensus on whether or not there's a consensus. Even your own comments contradict themselves. First you say there's a consensus on anthropogenic global warming, but you finish by saying that Singer has joined "the 'natural causes' camp." If he believes that GW is naturally-caused, then he disbelives that it's anthropogenic, which puts him in direct opposition to any so-called consensus.

OK, I've added the phrase "thought to be" in the last paragraph. I personally happen to believe in theories of human causation, but given how hard causation is to establish in climate science, I'd really rather not have this otherwise historical page become a policical battleground. If using qualifiers makes people happy, I don't see that it hurts anything. --jberkus 11/16/06

[edit] Inuit in Scotland?

I'm having difficulty with the line "six records of Inuit landing their kayaks in Scotland". I see the source, but I have to question how well established these landing are. From what I can tell, this comes from a radical and non-mainstrean interpretation of tales about the Orkney Finmen. The consensus seems to be that they were Lapplanders of some description. Considering the complete lack of signs of Inuit visitations to Iceland or the Faroes - both inhabited by Scandinavians at the time - and the difficulties posed by taking a kayak into those kinds of adverse currents, I should think it unlikely that Inuit travelled to Scotland in precolonial times. --Diderot 10:50, 8 June 2006 (UTC)

Okay, having failed to find any helpful confirmation, I'm removing the Inuit and Polar Bear line. --Diderot 20:33, 8 June 2006 (UTC)

Once again, every clear, authoritative reference I find to the possibility of Inuit landing in Scotland in kayaks at any time in history is, at best, controversial. I've added a disputed tag to reflect this. There's a difference between factual and on lots of web pages. --Diderot 14:07, 9 June 2006 (UTC)

Ian Whitaker. The Scottish kayaks reconsidered. Antiquity v51, n201, pg 41–45 (1977)

[...] The problem that the kayak becomes waterlogged after being immersed in water for 48 hours presents difficulties to this solution which could only be overcome if one postulated Olympic standards on the part of the travellers. [...]

Over the course of the article, Whitman, who had been the principal advocate of the idea that Inuit has been traversing difficult north Atlantic currents despite the questionable ability to carry enough water to make the trip, and the lack of kayak sightings in Iceland and the Faroes, and the construction of the Aberdeen kayak - the only surviving one - from Scots fir wood (which isn't impossible, east Greenland Inuit did use driftwood from Europe in boats), goes back on his original conclusion and decides that the most likely solution is Inuit kidnapped by whalers being dumped at sea with their canoes.

The traditional explanation - that the Orkney "Finnmen" were Nenets - seems to me still more rational than this new solution. But it certainly highlights how unconfirmed the identity of the kayakers who landed on the Scottish coast is.

Kayaks were not used for long distance travel, they were hunting tools. Even with favourable currents, it's hard to imagine taking enough water for the two to three week trip in a kayak. And for an accidental voyage, it's just not possible. Stopping in Iceland and the Faroes makes it just plausible, but it's hard to believe without maps or an idea where they were going that they could get to Scotland. You can't sleep in a kayak alone in anything but the very calmest possible water - Inuit go out in pairs if they plan to be on the water overnight so that one guy can keep the boat pointing into the waves. The Inuit don't simply follow the edges of the sea ice, it's too dangerous, and they don't hunt at the edges of the ice. And they never hunt further from home than they can take the food back to.

It's just not credible that they kayaked from Greenland.

--Diderot 20:02, 9 June 2006 (UTC)

But isn't it possible that the because the polar ice extended further south that it doubled as a land mass from which they could seek water, food and short term accomnodation? I never interpreted the "inuit in Scotand" anecdotes as meaning that they travelled in a straight line from Greenland. Grant65 | Talk 04:31, 17 June 2006 (UTC)

It's really unlikely. As I understand it, the Gulf Current was still operating. Iceland was not surrounded by polar ice. So in order to make this work, the Inuit have to travel a suicidal distance north along even the most southern possible extension of the ice cap, and then still further east, only to still be a week or more away from the Orkneys on open ocean. Second, the edge of the ice is a really dangerous place to be, even in a kayak. The ice doesn't just stop and form a shore, like land does. The edge is made up of sections of thin ice and broken ice that make it hazardous both to try walk over and to try to kayak along.

It's not quite categorically impossible, but even under the best of assumptions, Iceland and the Faroes ought to have even more tales of Inuit visitors than Scotland, but as far as I can tell they have none.

The polar bears are even less likely. Unless the ice cap actually came so far south that it touched the Orkneys, there's no way for polar bears to get there. They swim, but not across oceans. --Diderot 06:34, 17 June 2006 (UTC)

According to Broecker [8], "from 1650 to 1890 Iceland was surrounded by sea ice for an average of 2 months per year." 130.36.62.126 14:57, 20 June 2006 (UTC)

I removed the disputed quotation: "The Arctic pack ice extended so far south that there are six records of Inuit landing their kayaks in Scotland, and there are even reports of a Polar Bear harassing crofters in the Orkney Islands [9]." Not only is the cited document not a reliable source for such information (it's an epidemiological article, not history -- and the author fails to cite his source for the Eskimo story), but the quote is corrupted, and the cited article doesn't mention the polar bear story at all. A reliable source for this is going to have a footnote to the "six reports" themselves -- anything else is just repeating what sounds like an urban legend. Note also that whether it's possible to get to Scotland in a kayak it is wholly irrelevant to the question of whether it did occur and is documented on six occasions. Tkinias 16:53, 2 July 2006 (UTC)

[edit] Sydney

Sydney didn't have a modern "CBD" in 1836, let alone anything like the subject of the article Sydney central business district. I have removed the term and the link (again). I also suspect that the acronym CBD is not well-known outside Australia. Grant65 | Talk 12:35, 8 June 2006 (UTC)

[edit] "There is a wide consensus among climate scientists"

From: http://www.fumento.com/weblog/archives/2006/06/scientists_ok_g.html

"The AP contacted more than 100 top climate researchers by e-mail and phone for their opinion. Among those contacted were vocal skeptics of climate change theory," said the writer. Problem is, only 19 responded; 81 of the scientists (that means 81%, AP), apparently weren't eager to comment."

There is little evidence for a concensus: http://www.junkscience.com/Greenhouse/cause.htm http://www.amazon.com/exec/obidos/ASIN/0742549232/junksciencecom/104-6969063-4681548

Tom Davidson Richmond, VA

That quote is out of context....they asked 100 scientists, both so-called "sceptics" and mainstream scientists. Of these, 19 answered (not really a bad quota, given how few will have seen the movie by the time of the questioning), and of those, all or nearly all seem to be satisfied with it. As for the rest of your comment: JunkScience has an adequately descriptive name. Nearly everything that you find there will fit the label. There is no sign of serious doubt about the core global warming theory in the peer-reviewed scientific literature. All major academies of science and a huge number of other professional scientific organizations have issued statements supporting the theory (including the US National Academy of Sciences and even the American Geophysical Union). To my knowledge, no professional scientific organization officially opposes it. --Stephan Schulz 16:42, 7 July 2006 (UTC)

James Hansen became the hero of the global warming believers by making spectacularly wrong predictions. The "hockey stick" is exposed as a fraud, but still gets used. In the 1970s, the "scientific consensus" was that the Earth was about to cool. The temperature charts going back to the 19th century, the CO2 buildup, the greenhouse theory -- pretty much the same evidence was available at that time as now. Ice melts in arctic; its evidence of global warming. Ice builds up in the Antarctic, the drive by media ignores it. If you were seriously worried that the Earth was too warm, you'd blow up some nukes and shoot some soot into the air. The eco-freaks use global warming as a vehicle to promote policies like renewable energy and recycling that they devised back in the 1970s, supposedly to address the energy crisis. When the energy crisis collapsed, they found a new issue to attach the policies to. Kauffner 08:01, 21 January 2007 (UTC)

James Hansen made a series of 3 predictions based on different emission scenarios in a 1988 paper that was also used in his 1988 statement to the US senate. The most extreme of these is sometimes quoted out of contect by so-called global warming "sceptics" as proof of a failed prediction. However, the medium case, described as the most likely one by Hansen, and based on an emission scenario that is a good match for actual emissions, also shows a very good match for actual temperature.[10]

Global cooling never had consensus or even majority support. At best it was considered a possibility. That the mass media are not the pefect means to communicate complex science is not exactly new. However, ice formation depends on both temperature and precipation. In Antarctica, it is limited by precipation - Antarctica is technically a desert. --Stephan Schulz 08:59, 21 January 2007 (UTC)

Okay, but what about Hansen's prediction that the oceans would rise by several feet? Nothing like that has happened. If you leave out the El Nino-related warming that occurred around 1998, the satellite data shows no warming since 1979.[11] The media's focus on glaciers and ice is moronic because they are trailing indicators. The glaciers are now reacting to pre-1940 warming, which we've known about for a long time and which can't possibly be due to CO2 buildup. Kauffner 06:14, 22 January 2007 (UTC)

You seem to work on hearsay, not on original sources. Where Hansen did predict that? In his 1985 Nature paper he gives quite conservative predictions. Last year discoveries about increased ice sheet melting made some researchers increase the predictions from 0.3 to 1.0 m per century (see for example the Science Magazine 2006 Science Breakthough #3). I believe the "several feet" prediction you write about was also supposed to happen in a century or two. Don't be so hasty. It will come in due time.

Also your claims that satellites do not see global warming is simply rehashing old arguments that have been already refuted (Wentz and Schabel 1998 who "discovered that the original satellite data, published in 1995, was not adjusted for the natural decay of spacecraft altitude caused by atmospheric drag" and all debate that followed: for example the Science papers on the subject). A consensus seemed to be reached in 2005 (a Nature news piece on the new consensus): "Together, the reports conclude that the observed tropospheric temperature trends are consistent with a warming world".

I would not agree that the Hockey Stick has been recognized as fraud. It is Mann (the main "fraudster"), not von Storch (the skeptic), after all, who is given the privilege to write the newest review paper on the subject (Michael E. Mann, 2007, Climate Over the Past Two Millennia). Also the NRC 2006 report Surface Temperature Reconstructions for the Last 2,000 Years (the closest to a consensus you can get) says: "It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries. This statement is justified by the consistency of the evidence from a wide variety of geographically diverse proxies. Less confidence can be placed in large-scale surface temperature reconstructions for the period from A.D. 900 to 1600. Presently available proxy evidence indicates that temperatures at many, but not all, individual locations were higher during the past 25 years than during any period of comparable length since A.D. 900".

Enough for now. Do you have any sources of your own to match these? --Friendly Neighbour 07:13, 22 January 2007 (UTC)

To that, let me just add satellite temperature measurements and Image:Satellite Temperatures.png. --Stephan Schulz 08:44, 22 January 2007 (UTC)

So the upshot of your argument is that the Hockey Stick is valid and that the Little Ice Age is a hoax? I'm sorry, but I find this point of view hard to take seriously. Many non-hockey stick shaped graphs of climate history have been produced, including two shown in this article. The Image:2000 Year Temperature Comparison.png graph that appears all over Wikipedia is certainly not a hockey stick.

It sure looks like a hockey stick to me if you look at the last two hundred years. ~~

Here is a side-by-side comparison of two graphs showing the Hockey Stick and non-hockey stick versions of climate history. Here is a page summarizing the McIntyre and McKitrick critique of the Hockey Stick. I don't have any problem with NRC's conclusion that that the last few decades have been warmest for 400 years -- that's just saying we are now out of LIA. The 1920-40 warming occurred before CO2 buildup was a major factor, so it shouldn't be grouped together with post-1980 warming.

Finally, citing entire books is not a very useful way to do sourcing. Readers should not have to hunt through volumes of material just to confirm an assertion. Kauffner 12:54, 22 January 2007 (UTC)

Do you address Tom Davidson, as the formatting of your edit suggests, or someone else? I can reply only for myself (and some of the content of our edit suggests that you replied to me). I see no problem with the Little Ice Age. I see no problem with the last decades being the warmest in 400 years and possibly even in 1000 (the "hockey stick"). The two facts are compatible, aren't they?

I simply do not understand where the funny graph you cite came from. I do not think it is from a peer-reviewed scientific paper. It's author, Christopher Monckton, never wrote a peer-reviewed paper according to Science Citation Index (Expanded), unless he is the author of MONCKTON C, "HIV TRANSMITTED BY KISSING" BRITISH MEDICAL JOURNAL 294 (6573): 706-706 MAR 14 1987 - which probably does not count as a paper on climate, anyway. The McIntyre & McKitrick (2005) paper was probably known to the National Research Council (NRC) panel which made a report on this very subject in 2006 writing what it wrote (in fact it discussed the paper's findings on pages 86-88 and 105-107). I cited it, "an entire book", because it is the actual consensus we have now (or the best thing next to it). You could spend some of your time reading at least the conclusions I took the citation from - the report has more weight than any number of propagandist blogs you seem to prefer.

Of course, I do see that not everybody agrees with the consensus but no consensus (even on the shape of our Earth) has a 100% following. --Friendly Neighbour 14:00, 22 January 2007 (UTC)

K started off with global cooling but was obliged to admit that was wrong. Then sea level rise, and that wrong too. Now he is onto dodgy graphs: see MWP and LIA in IPCC reports for the source of that (summary: it was only a schematic, abandonded a long time ago) William M. Connolley 14:06, 22 January 2007 (UTC)

And it's a conspiracy theory, to boot. Those are always fun. (Don't tell Monckton about the IPCC Working Group I fleet of black helicopters.) Raymond Arritt 14:14, 22 January 2007 (UTC)

IT seems the "global cooling" Christopher Monckton and the "HIV through kissing" Christopher Monckton are really the same person. IMHO, not a record to be proud of. --Friendly Neighbour 14:25, 22 January 2007 (UTC)

Don't worry, WMC, I haven't forgotten global cooling! Here we go: "An increase by only a factor of four in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 degrees Kelvin… sufficient to trigger an ice-age."—Dr S I Rasool and Dr S H Schneider, Science, July 9, 1971.[12] Stephen Schneider, of course, being the same guy who went on the become Mr. Global Warming in the 1980s. For many years, he was quoted in every news story on global warming -- appearently the only scientist working on the subject at that time. Bring back aeosols and CFCs -- fight global warming! Kauffner 14:40, 22 January 2007 (UTC)

• I don't see why you need to link off-wiki: that passage is on the global cooling page. Perhaps you haven't had time to read it yet. And as far as I know, that statement may still be true - if you know otherwise, do let us know. Of course few people would start with such an If, nowadays William M. Connolley 15:09, 22 January 2007 (UTC)
• Kauffner, what's your point? Apart from the fact that you get your information not from the original source, but from a blog that has cut one sentence (and not a complete one, at that) from the paper and gives an incomplete source (title and pages are customary), why do you think this statement is significant? Since we have massively reduced sulphate aerosol emissions since the 70s, what do you expect? And what does this have to do with the discussion so far?--Stephan Schulz 15:11, 22 January 2007 (UTC)

SS: The context of the Schneider quote is here. I thought the implication of what you wrote before was that nobody who mattered endorsed global cooling. But Schneider gave a testimonial for Lowell Ponte's The Cooling (1976), which predicts global cooling based on the Milankovitch cycles.

FN: So after all that, the Hockey Stick is only "possibly" valid? I can't disagree there! Kauffner 16:15, 22 January 2007 (UTC)

Haven't you heard that all scientific statements are only hypotheses? But there is a long way from there are still some doubts about the "hockey stick" (a statement I could sign under) and the "hockey stick" is exposed as a fraud (your original statement which made me join the discussion as I cannot agree with it). --Friendly Neighbour 16:25, 22 January 2007 (UTC)

K doesn't seem to be aware that people habitually chop off a rather important sentence from the Schneider quote: Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both. Isn't it odd that they remove the bit I've bolded. I wonder why they do it? William M. Connolley 16:42, 22 January 2007 (UTC)

That's of course unfortunate. But it doesn't change the fact that Schneider also said this: "we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have." That's saying, Go forth and falsify. I wonder why he never brings up his aeosol theory when he talks about global warming. What's all this Kyoto nonsense when the answer could be under our arms? Kauffner 17:17, 22 January 2007 (UTC)

[edit] Assertions

I'm seeing two kinds of assertions here:

1. The assertion that scientists outside Wikipedia disagree.
2. The assertion that one group of scientists is right.

I would suggest that we avoid the second sort of assertion, in light of Wikipedia's policies on original research and Attribution.

• I'm inclined to make an exception for Dr. C, who actually *is* a scientist, but I hope he'll be careful to distinguish between his own views and 'verifiable secondary sources'.

I'm not trying to get the article to agree with any particular viewpoint - I just want it to indicate what the range of scientific views is, and in particular what proportion of scientists adhere to each view. And I hope that we'll document everything in a way that the average educated laymen can verify. --Uncle Ed 15:14, 20 March 2007 (UTC)

Ed, I'm confused. If you're worried about sci-cons type stuff, why are you tagging the LIA article, which doesn't even mention it. If you think *this* article is POV, please say why William M. Connolley 15:20, 20 March 2007 (UTC)

Let me explain. This section is a discussion of whether it is 'neutral' to say that "There is a wide consensus among climate scientists". Contributors here disagree about whether this is a matter of fact, and the dispute did not end in consensus.

Or did I miss something? Let's take a vote.

The article ends like this:

• The scientific consensus is that warming over the last 50 years is caused primarily by the increased proportion of CO2 in the atmosphere caused by human activity.

How many article contributors feel that it is "neutral" to say this?

Agree:

Disagree:

1. Uncle Ed

Other:

Taking a vote is a last resort, not a first. Now you've explained your problem, we can discuss it. Firstly, it doesn't justify tagging the entire article - tag the end if you must. Secondly, the text is supported by the sci opp article. I don't see your problem. Please suggest alternative text if you don't like whats there William M. Connolley 18:40, 20 March 2007 (UTC)

By sci opp presumably you mean Wikipedia's article on scientific opinion on climate change. Maybe we should copy a verifiable quote from that article into the disputed section. --Uncle Ed 19:11, 20 March 2007 (UTC)

I've made it simply a link to sci opp. Does that satisfy? There is no need to quote from that page, since it is linked to William M. Connolley 20:15, 20 March 2007 (UTC)

I was pretty satisfied but I removed the article the which made it sound so monolithic. Okay? —The preceding unsigned comment was added by Ed Poor (talk • contribs) 20:48, 21 March 2007 (UTC).

OK, good William M. Connolley 21:35, 21 March 2007 (UTC)

[edit] Oort Minimum? Wolf Minimum?

The graph in the "Causes" section has labels for both Oort Minimum and Wolf Minimum, but neither of these is described in the accompanying text, nor do Wikipedia pages exist for them. By contrast, both Maunder Minimum and Spörer Minimum are mentioned and have pages of their own.

Could someone with more knowledge of the subject matter please rectify this?

Deven 21:24, 25 August 2006 (UTC)

[edit] Are you certain that this is written sufficiently confusingly? Could this be a little less well edited?

"...Some confine the Little Ice Age to 1550-1850, lasting approximately from the 14th to the mid-19th centuries while others prefer a span from the 13th to 17th centuries."

For total brainfreeze, I would need just slightly more confusion.

Hopiakuta 19:46, 6 September 2006 (UTC)

[edit] End of LIA reversions

SEW reverted [13] my new wording. I don't know why because all he said was "rv". In my view, "There is a wide debate among climate scientists, however, whether the present sharp upturn in temperatures is caused primarily by the increased proportion of CO₂ in the atmosphere caused by human activity." is inaccurate or confusing - as all the other climate type pages say, there is a consensus that the current upswing is indeed human-caused, at the very least over the last 50 years. For the previous 100 there is less agreement, but probably not a wide debate William M. Connolley 09:29, 6 November 2006 (UTC)

[edit] Eds Eds

OK, so I reverted Ed Poor. I didn't much like most of it, but I particularly dislike using Image:Fig1 climate cycle.jpg in place of the graph we had already. This graph is obsolete. It is based on the IPCC '90 graph which itself is based on just about nothing: see MWP and LIA in IPCC reports William M. Connolley 15:13, 20 March 2007 (UTC)

No problem. It's an honor to have your input, and I always appreciate the chance to read your explanations. I had no idea it was 16 years out of date. Maybe it belongs in the Global warming controversy article. --Uncle Ed 15:24, 20 March 2007 (UTC)

It's understandable you had no idea it was 16 years out of date. That "1990" in the caption is so mysterious. Raymond Arritt 15:48, 20 March 2007 (UTC)

Oh, that. Okay, but how much has the paleoclimate data relating to the Little Ice Age changed since then? And who says so? --Uncle Ed 19:13, 20 March 2007 (UTC)

Sigh. I do wish you'd just go and *read* MWP and LIA in IPCC reports instead of fiddling with it; then you'd know why that picture is obsolete William M. Connolley 20:13, 20 March 2007 (UTC)