Talk:Arctic shrinkage

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I think this article should be merged with the 'Polar ice packs' article. the latter has more information on Arctic shrinkage then this one. —Preceding unsigned comment added by 132.72.87.111 (talk) 22:38, 4 November 2007 (UTC)

Agreed. The relevant section also predates this article by a few years. Afasmit (talk) 21:24, 25 November 2007 (UTC)
Disagree. A lot has been added to this article since November 2007. See here.Ferrylodge (talk) 04:03, 7 February 2008 (UTC)

Contents

[edit] Here's an inconvenient truth

"Recent cold snap helping Arctic sea ice, scientists find" [1]

Anyone want to dare add that to the article and get shot down for it? 67.135.49.254 (talk) 06:42, 18 February 2008 (UTC)

I dared. Thanks for the info.Ferrylodge (talk) 07:04, 18 February 2008 (UTC)

[edit] Movie

Could we lose the movie? It screws up my computer :-( William M. Connolley (talk) 19:35, 8 March 2008 (UTC)

Fine with me.Ferrylodge (talk) 21:21, 10 March 2008 (UTC)
I suggest this NASA image as a replacement. Mostlyharmless (talk) 06:39, 21 March 2008 (UTC)
Done. Mostlyharmless (talk) 07:07, 21 March 2008 (UTC)

[edit] Title?

The title is a bit odd. The Arctic isn't shrinking (I don't think it can, its geographically defined). Arctic ice cover is shrinking William M. Connolley (talk) 21:16, 10 March 2008 (UTC)

We're talking about shrinkage in the Arctic, not shrinkage of the Arctic. I think the title is okay. Just like Moon landing refers to landing on the Moon, not landing of the Moon.Ferrylodge (talk) 21:24, 10 March 2008 (UTC)
Yeees, but the connection to sea ice is missing. Arctic permafrost is shrinking, as is the snow cover. The article should have "sea ice" somewhere in the title. You can't use it for a link otherwise William M. Connolley (talk) 22:02, 10 March 2008 (UTC)
I don't have strong feelings one way or the other about this. However, if you change the title of this article, I think you ought to change the title of Moon landing to something like Landing of people on the Moon.Ferrylodge (talk) 22:22, 10 March 2008 (UTC)
You're being silly. In the case of moon landing, there is no doubt about what was landing. For example, "19xx saw the first moon landing" works. "In 2007, there was a lot of arctic shrinkage" doesn't. "In 2007, there was a lot of arctic sea ice shrinkage" does William M. Connolley (talk) 22:35, 10 March 2008 (UTC)

If you want to go to the trouble of changing the title here, and changing all the links to it from other articles, then I won't have any huge objection. However, the current title is conveniently short, and already works in sentences of other Wikipedia articles (e.g. "scientists have predicted that the North Pole may become seasonally ice-free, perhaps as early as summer 2008, due to Arctic shrinkage" and "the pack ice is being reduced and this Arctic shrinkage may eventually make the waterways more navigable"). I didn't name this article, but it seems like a concise and catchy title.Ferrylodge (talk) 23:07, 10 March 2008 (UTC)

You won't have to change all the links to here, there are bots that do that. I support the name change to Arctic sea ice shrinkage or similar. Mostlyharmless (talk) 22:22, 23 March 2008 (UTC)
The Greenland Ice sheet (in the lead paragraph) is not sea ice. Do we want to change the scope of the article, or merely make the title more descriptive? If the latter then, "Arctic ice shrinkage" might be the way to go.Ferrylodge (talk) 22:28, 23 March 2008 (UTC)

When I started the article, I chose the name believing it to be concise, accurate, citable (thousands of ghits), neutral, and within WP:NAME convention for a physical geography article with the intended scope of: measureable physical geographic changes to the Arctic; the scientific research (cause[s], modelling, etc.); the effects (on fauna, flora, man, society, etc). But if the article name doesn't comply with WP:NAME, or if there's consensus amongst the article's main editors (or the appropriate Wikiprojects) to a name change proposal, then it should be changed. --Rosiestep (talk) 05:47, 24 March 2008 (UTC)

Now that you mention it, if using the definition of Arctic that refers to climatic and environmental conditions, then the Arctic could be said to be shrinking - in which case a wider scope for the article than merely ice might be in order. Mostlyharmless (talk) 05:54, 24 March 2008 (UTC)

[edit] What would happen if the Arctic completely melted?

Worldwide sea level would rise if Greenland were to melt. However, this factoid was recently removed.[2] Here's what our Wikipedia article said:

“ If the ice on Greenland were to completely melt during some future century, then worldwide sea levels would rise an estimated 7 metres (23 ft).[1][2] ”

[1]Black, Richard. "Earth - melting in the heat?", BBC News, 2007-05-18. Retrieved on 2008-01-03. 

[2]Climate Change 2001: The Scientific Basis (Table 11.3). Intergovernmental Panel on Climate Change (2001-02-16). Retrieved on 2007-12-24.

The first of these two references says: "A complete melt of the ice sheet would cause a global sea level rise of about 7m; but the current picture indicates that while some regions are thinning, others are apparently getting thicker." The second reference provides the "sea-level rise equivalent" of ice in Greenland, the Antarctic, et cetera. I think this particular factoid that was deleted is useful. It doesn't allege that Greenland will melt, but rather explains the importance of ice for suppressing sea level. And that is a very important function of Arctic ice.Ferrylodge (talk) 23:52, 31 March 2008 (UTC)

The way its placed makes it appear to seem relevant. Indeed, if it isn't relevant its hard to see why its there. A better formulation is something like "the gr ice sheet contains enough fresh water as ice to raise sea level by 7 m" and maybe continue with something like "under gw it is expected to melt eventually, in a timescale that is unclear, but of the order of thousands of years" William M. Connolley (talk) 21:52, 1 April 2008 (UTC)
Referencing Wikipedia:NOT#CRYSTALBALL, the example, "The gr ice sheet contains enough fresh water as ice to raise sea level by 7 m", is a measurement statement, and, if the accuracy is supported by citation, appropriate in this article. I think the other example, "If the ice on Greenland were to completely melt during some future century, then worldwide sea levels would rise an estimated 7 metres (23 ft)", has speculative elements ("If", and "some future century"), so it needs a copyedit. --Rosiestep (talk) 23:03, 2 April 2008 (UTC)
Okay, I added William's sentence "the gr ice sheet contains enough fresh water as ice to raise sea level by 7 m". As to whether we should add a further sentence about the unlikelihood about any complete melting of Greenlabnd in the near future, I'd support that if it's phrased well and reliably sourced.Ferrylodge (talk) 23:34, 2 April 2008 (UTC)
Yeeeessss... but what is this doing under "recent statements"? William M. Connolley (talk) 21:50, 3 April 2008 (UTC)
I moved it out of the "recent statements" section, although the cited news article seemed fairly recent (2007). Anyway, I hope this is better now.Ferrylodge (talk) 22:04, 3 April 2008 (UTC)

(undent)This edit by William removed a link to what I thought was a very interesting article in the journal Nature that I had inserted here. William's edit also reverted a previous edit that I made here, without explanation. Was the latter revert intentional? If so, why would we prefer a gramatically incorrect sentence like this: "However the amount of perennial ice, were below levels measured in the previous winter"? Why can't we say: "However the amount of thick perennial ice was below levels measured in the previous winter"? The word "thick" is also important here, because that was emphasized by the cited article (e.g. it was in the title of the cited article).

Sometimes people make small grammar mistakes in editing. Sometime people even spell "grammatically" wrongly. But spelling and grammar flames are lame - just correct the grammar William M. Connolley (talk) 23:22, 5 April 2008 (UTC)
You reverted this edit. May I restore it?Ferrylodge (talk) 23:29, 5 April 2008 (UTC)

Regarding deletion of the material based on the Nature article, do others agree with William that the Nature article is not notable? Here's the material that William deleted:

Models predict that Greenland will become warm enough by 2100 to begin an almost complete meltdown over the course of the following several centuries.[1]
[1] Gregory, Jonathan; Huybrechts, Philippe; Raper, Sarah. “Threatened loss of the Greenland ice sheet” Nature, 428, 616 (2004): “The Greenland ice-sheet would melt faster in a warmer climate and is likely to be eliminated — except for residual glaciers in the mountains — if the annual average temperature in Greenland increases by more than about 3 degrees centigrade. This would raise the global average sea-level by 7 metres over a period of 1000 years or more. We show here that concentrations of greenhouse gasses will probably have reached levels before the year 2100 that are sufficient to raise the temperature past this warming threshold.”

This seems like interesting material to me. William's edit summary says: "the actual value for 2100 seems rather more useful than some dim-and-distant possibility." But I don't agree that the deleted material is about a dim and distant possibility. It's saying that by 2100 Greenland will have reached a sufficiently high temperature to eventually completely melt. Might I suggest that we can include both the projected (very tiny) sea level increase by 2100 and the info that William deleted?Ferrylodge (talk) 21:43, 5 April 2008 (UTC)

Whats your explanation for deleting the small loss up to 2100, then? [3] William M. Connolley (talk) 23:22, 5 April 2008 (UTC)
I didn't see where in the cited source you got "10 cm" from. I still don't. From Figure 11.16, it looks to be less than 25 cm, but I don't see "10 cm" mentioned.Ferrylodge (talk) 23:24, 5 April 2008 (UTC)
OK, I found a source for the estimated Greenland contribution to sea-level change by 2100. See Huybrechts, Philippe; de Wolde, Jan. "The dynamic response of the Greenland and Antarctic ice sheets to multiple-century climatic warming”, Journal of Climate, 12(8), 2169-2188, 2174 (1999). They estimate abiut 10 cm for a medium forecast, and 21 cm on the high side. So, I'll rephrase the article accordingly, and see what happens.Ferrylodge (talk) 14:21, 6 April 2008 (UTC)
I read it off the figure you were using because I was feeling lazy. 1999 is too old. IPCC AR4 is the obvious source [4] and table 10.7 looks to be what we want. "10 to 20 centimetres" is not correct, you are erring on the high side (assuming you're using table 2, you've picked the mid and high but omitted the low; and you've used numbers up to 2130 which is not what people usually mean by 2100. If insead you use fig 5, then low is 3.5 cm and high is 20.8. Are you being careless or is it something worse? But anyway, that paper is too old). AR4 gives us: [0.01-0.05] [0.01-0.06] [0.01-0.08] [0.01-0.07] [0.01-0.08] [0.02-0.12] as the 95% ranges (in m) for various scenarios over the 21st century. Picking the mid-range of these I think that 0.03-0.07 m = 3-7 cm is a fair estimate up to 2100.
I don't think I've been careless, or "something worse." I specifically said that I was looking at Huybrechts, Philippe; de Wolde, Jan. "The dynamic response of the Greenland and Antarctic ice sheets to multiple-century climatic warming”, Journal of Climate, 12(8), 2169-2188, 2174 (1999). At page 2174, there's this: "For instance, by the year 2100 in the middle scenario...the Greenland ice sheet would contribute +10.6 cm...but in the high scenario...+21.2...." Did I misinterpret those numbers? I don't think so, but if I did it certainly was not intentional. You say that I have "used numbers up to 2130 which is not what people usually mean by 2100." Where do you get the idea that I was using numbers up to 2130? I'm trying to be a neutral editor here, whether you think so or not.
My apologies: I've struck that out. I misread what was going on. You can get low, mid and high from the table; the paper itself is being somewhat misleading by not including "low" in the text to balance "high" William M. Connolley (talk) 22:54, 6 April 2008 (UTC)
You say that "Models predict a sea-level contribution of 3 to 7 centimetres from changes to the mass balance of Greenland during the 21st century." I am looking at the cited Table 10.7, and I do not understand where you get those numbers from.Ferrylodge (talk) 22:12, 6 April 2008 (UTC)
The ranges I gave above in brackets are from that table. Lowest is [0.01-0.05]; highest is [0.02-0.12]. Those are 95% conf levels, so I don't think we want to use 0.01-0.12 as the likely range. Averaging the low range gives a midpoint of 0.03; the high, 0.07 m William M. Connolley (talk) 22:54, 6 April 2008 (UTC)
Re [5] mass balance vs melting: be aware that ppn goes up, so a MB contribution of 5 cm corresponds to melting of more than 5 cm's worth William M. Connolley (talk) 07:21, 7 April 2008 (UTC)
How much more? I think it would be helpful if we could give numbers for sea level rise rather than for mass balance, because the latter concept will not be well understood by lay readers.Ferrylodge (talk) 15:42, 7 April 2008 (UTC)
The mass balance *are* the numbers that correspond to sea level rise. The ones for melting don't, because there can be compensating changes in precipitation. SLR ~ MB ~ PPN-Melt William M. Connolley (talk) 20:57, 7 April 2008 (UTC)

[edit] TOC

The Table of Contents seems awfully far from the top of the article. Any way to move it up a bit?Ferrylodge (talk) 02:19, 5 April 2008 (UTC)

You're right; I just moved it. StephenHudson (talk) 13:03, 5 April 2008 (UTC)

[edit] 1000 degrees?

The quote: "The reduction in the intensity of cold (temperatures) during winter over these last 20 years corresponds to an accumulation (rise) of 1,000 degrees Celsius." [22] doesn't make sense to a layperson such as myself - what does the 1,000 degrees represent? Surely the Arctic isn't the hottest place on Earth? ;) Mostlyharmless (talk) 07:53, 7 April 2008 (UTC)

I agree that this quote will make no sense to lay readers unless it is properly explained.Ferrylodge (talk) 15:42, 7 April 2008 (UTC)
I removed the quote, which definitely seemed unclear. I assume it was referring to a degree days concept, where one adds up the difference between the average temperature of each day and some baseline temperature over a certain period. Since the original source does not seem to offer any more information to clear up the quote, it seems best to remove it. If someone can better explain it, without original research, then they should feel free to replace it. StephenHudson (talk) 18:07, 7 April 2008 (UTC)

[edit] Image

The use of the image Image:Arctic_Sea_Ice_area_thickness_and_volume_trends.png here is deceptive. It suggests that we are currently experiencing a downward trend in Arctic Sea Ice. In reality this image was created in 2006 and the downward trend after 2006 is only a conjecture. The hypothetical nature of the trend depicted needs to be acknowledged in the caption. —Preceding unsigned comment added by 128.187.0.164 (talk) 16:29, 15 May 2008 (UTC)

Looks like that image may be deleted soon anyway.[6]Ferrylodge (talk) 17:23, 15 May 2008 (UTC)


[edit] Computer models predict that the sea ice area will continue to shrink in the future

Is that true? As I understnad it, 2007 was unpredicted by the models. Indeed, if we were on the model track the ice extent would be considerably higher William M. Connolley (talk) 21:26, 23 May 2008 (UTC)

I modified the punctuation a little bit, so there is now a cite at the end of that sentence. It seems the cite supports the sentence. What do you think?Ferrylodge (talk) 22:42, 23 May 2008 (UTC)
Perhaps change to - "Arctic Sea ice is melting faster than global climate models predict[7][8]; in fact, the record low ice extents in 2005 and 2007 are below the predictions of a regional climate model which indicates the Arctic Sea will be ice free in 2013[9]." Sagredo⊙☿♀♁♂♃♄ 00:46, 24 May 2008 (UTC)
All that article says is that 2005, 7 weren't incorporated into the model. It doesn't say the model predicts lower ice in 5, 7. Ice free in 2013 is implausible, BTW, but unfortunately there is no doubt he actually said it in a RS :-( William M. Connolley (talk) 08:19, 24 May 2008 (UTC)

(undent)Here's what our Wikipedia article says:

Computer models predict that the sea ice area will continue to shrink in the future,[citation needed] though there is no consensus on when the Arctic Ocean might become ice-free in summer; one study states this might happen before 2015, while a more common theory estimates between 2040 and 2100.[1]

[1]Amos, Jonathan. "Arctic summers ice-free 'by 2013'", BBC News, 2007-12-12. Retrieved on 2007-12-16.

The question is whether the cited article (by Amos) supports the blockquoted sentence. I beleieve it clearly does. The Amos article says: "Scientists in the US have presented....modelling studies indicat[ing] northern polar waters could be ice-free in summers within just 5-6 years…[O]ther teams have variously produced dates for an open summer ocean that, broadly speaking, go out from about 2040 to 2100."

I don't see why this quoted material from the cited reference does not support the blockquoted material in this Wikipedia article. There's no reason to keep the "citation needed" tag, is there?

In fact, you can ignore the bold italicized language that I just quoted from the cited reference. Why doesn't the first part of our Wikipedia sentence ("Computer models predict that the sea ice area will continue to shrink in the future") follow logically from the last part of our Wikipedia sentence ("there is no consensus on when the Arctic Ocean might become ice-free in summer; one study states this might happen before 2015, while a more common theory estimates between 2040 and 2100")? Ferrylodge (talk) 18:32, 24 May 2008 (UTC)

Because, taking this at a rather primitive level, computer models didn't predict the low ice levels of 2007. So they aren't predicting lower ice for 2008 or 9. Models predict a general long term ice decline. Also, we shouldn't be giving the 2013 story such prominence, since its an extreme minority view William M. Connolley (talk) 11:11, 25 May 2008 (UTC)

(undent)Models have been tweaked by inputting revised data for 2007, so the predictions have changed accordingly. As you know, that's how computer models work; when new data is collected, the new data is inputted into supercomputers, and predictions are thus revised. How about if we modify what this Wikipedia article says, to reflect your concerns:

Computer models predict that the sea ice area will continue to shrink in the future, though there is no consensus on when the Arctic Ocean might become ice-free in summer.[1] Computer models have been criticized in the past for underestimating key melting processes.[1] One study now states that an ice-free Arctic Ocean might occur before 2015, while a much more common theory estimates between 2040 and 2100.[1]

[1]Amos, Jonathan. "Arctic summers ice-free 'by 2013'", BBC News, 2007-12-12. Retrieved on 2007-12-16.

If you disagree with this, please be specific about which part you think needs improvement. It all seems to be supported by the cited source. This revised version would include the fact that computer models have been criticized, and would also say that the 2040-2100 estimate is much more common.Ferrylodge (talk) 17:55, 25 May 2008 (UTC)

It doesn't address we shouldn't be giving the 2013 story such prominence, since its an extreme minority view. And where does Models have been tweaked by inputting revised data for 2007, so the predictions have changed accordingly come from? William M. Connolley (talk) 19:55, 25 May 2008 (UTC)
I am not suggesting to put the words Models have been tweaked by inputting revised data for 2007, so the predictions have changed accordingly into the article. You're aware of that right? Where that comment of mine came from is explained in my immediately following comment: "As you know, that's how computer models work; when new data is collected, the new data is inputted into supercomputers, and predictions are thus revised." You acknowledge (don't you?) that newly acquired data is fed into computers to revise a model's predictions, right?
As far as 2013 being an extreme minority view, the cited source doesn't say that it's an extreme minority view. And the immediately following sentence in the article indicates that there are even more "extreme" views: "According to a senior advisor to the Norwegian Ministry of the Environment, the Arctic polar ice cap could be completely gone during the summer of 2008." Do you have a reliable source that says 2013 is an extreme minority view? I'm proposing to say that the "much" more common view is 2040-2100. Why is that not adequate?
You've criticized computer models for not predicting the large extent of 2007 melting, and yet you seem to also be criticizing those scientists who have decided to take the 2007 melting into account so as to revise their predictions.
Maybe it would help if we stick to the issue at hand: removal of the cn tag on the statement that, "models predict that the sea ice area will continue to shrink in the future." Isn't that precisely what the footnoted 2040-2100 prediction says?Ferrylodge (talk) 20:12, 25 May 2008 (UTC)
Is there any objection if I remove the cn tag? The footnoted 2040-2100 prediction supports the statement that "models predict that the sea ice area will continue to shrink in the future."Ferrylodge (talk) 05:05, 26 May 2008 (UTC)
Here's another source that states computer models predict melting. "Arctic sea ice is melting at a significantly faster rate than projected by even the most advanced computer models"[10] So I think the cn tag should be removed. It's also interesting to note that this was before the minimum of September 2007. While 2013 may be an minority view, there does seem to be a significant school of thought that the observed melting is well ahead of the GCM's. [11] Nor does it seem that 2007 was a fluke, predictions for September 2008 look grim. [12] Sagredo⊙☿♀♁♂♃♄ 05:10, 26 May 2008 (UTC)
I see this all going nowhere. But to try... According to a senior advisor to the Norwegian Ministry of the Environment, the Arctic polar ice cap could be completely gone during the summer of 2008 is utter twaddle; no-one believes it.
Arctic sea ice is melting at a significantly faster rate than projected by even the most advanced computer models - yes; thats exactly what I am saying. Therefore, models are not currently predicting anything useful from the 2007 baseline; because 2007 (obs) is below 2007 (modelled). If you took the models literally, they are prdicting *more* ice in 2008.
You stated that Models have been tweaked by inputting revised data for 2007, so the predictions have changed accordingly. I see no evidence for that. Which models are you referring to? Please be specific William M. Connolley (talk) 10:04, 26 May 2008 (UTC)
Dr. C is right that Dr. Orheim must have been drinking when he made the "gone in 2008" statement, and it shouldn't appear in the lead. If for no other reason than the use of the term Polar cap which is usually defined to include the Greenland Ice Sheet. But I still think Maslowski's study (2013) should be mentioned, because it is representative of those who think that the IPCC models are far to conservative with regard to Arctic sea ice.
How about - "The most advanced computer models gave projections that the Arctic Sea would be seasonally ice free between 2040 and 2100, however, the ice has been melting at a significantly faster rate since at least 2005. A regional climate model predicts an ice free Arctic Ocean before 2015, but this has limited acceptance by scientists." - Sagredo⊙☿♀♁♂♃♄ 17:01, 26 May 2008 (UTC)
It might be good to have a new section that addresses the successes and failures of computer models. Generally speaking, some scientific models are technically failsafe, because they give a very low probability to almost any conceivable outcome. Other models offer more definitive predictions. Models are only as good as the assumptions upon which they are based, and on the accuracy of the data that is fed into them. Regarding Arctic ice models in particular, if all models turn out to have provided erroneously conservative predictions, then the question becomes whether to just ignore models, or to adjust the models so they're less conservative. Models have been tweaked over the years by adjusting the assumptions upon which they're based, and by inputting more accurate data into them, so that the predictions have changed accordingly; if we decide to create a new section about modelling, then I'd be glad to provide refs about this.Ferrylodge (talk) 21:52, 26 May 2008 (UTC)

As best I can tell, there seems to be consensus that the statement in the article ("models predict that the sea ice area will continue to shrink in the future") is supported by the cited source. The controversy seems to be whether those models are useful or not, but they do predict continued shrinkage, and so I'll remove the tag for now.Ferrylodge (talk) 20:55, 26 May 2008 (UTC)

[edit] Image

While it may have seemed to be an update to a more current image, the use of the image of April ice extents (April of each year) is quite different from using the Septembers or each year, when the minima occur. As this section of the article is about the record minimum of Sept 2007, and how it compared with computer projections, this image is more appropriate. Ferrylodge's idea of a section about the relationship of the model's projections and the observed melting is a good idea. Also as we move away from 2007 in time, it would seem to make sense to convert the 2007 section into a historical perspective. That the ice had been in decline for some time, setting record minima every few years, then notably so in 2005, and that so very many (most?) scientists found the 2007 minimum shocking. Sagredo⊙☿♀♁♂♃♄ 02:29, 6 June 2008 (UTC)

I went ahead and condensed the 2007 material.Ferrylodge (talk) 03:01, 6 June 2008 (UTC)