Talk:Sea level rise/Archive 3

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Archive 1

Archive 2

Archive 3

Archive 4

Archive 5

Archive 6

A sentence in the lede

The Intergovernmental Panel on Climate Change (IPCC) projected sea level rise of 18 and 59 cm (7.1 and 23 in) during the 21st century, estimating that the rate would further increase

suffers from two problems.

1. The wording about the range doesn't hint that it is a range.
2. The phrase in bold isn't supported in the source. Did I miss something?

My planned replacement:

The Intergovernmental Panel on Climate Change (IPCC) sea level rise projections range from 18 to 59 cm (7.1 and 23 in) during the 21st century.

For the very anal, the IPPC does not have a projection, but a series of projections, and the values chosen are the low end of the lowest projection and the high end of the highest projection. It is technically flawed to create a range this way, but it would be unreasonably wordy in a lede paragraph to spell out the gory details. If someone has a better idea, please chime in. As for the second phrase, unless I missed something, it is not supported, unless it is bad English and the author was trying to say something like "rise is expected to continue into the 22nd century".--SPhilbrick(Talk) 21:42, 31 December 2011 (UTC)

Sounds good. ~ J. Johnson (JJ) (talk) 22:28, 31 December 2011 (UTC)

I agree but would go further.

In 2007, the Intergovernmental Panel on Climate Change (IPCC) projected that during the 21st century, sea level will rise another 18 to 59 cm (7.1 and 23 in), not counting possible changes in the Greenland and Antarctic ice sheets or increased warming due to carbon-cycle feedbacks.

See for example, pg 70 of IPCC 2007 AR4 WG1's technical summary. NewsAndEventsGuy (talk) 22:37, 31 December 2011 (UTC)

I like that with a tiny modification. Given that we are using the summary for the source, I thought I would use their exact wording:

In 2007, the Intergovernmental Panel on Climate Change (IPCC) projected that during the 21st century, sea level will rise another 18 to 59 cm (7.1 and 23 in), not counting "future rapid dynamical changes in ice flow".

The problem with the carbon-cycle feedback phrase is that it is one-sided, while the report clearly refers to increased uncertainty, meaning that could contribute positively or negatively.--SPhilbrick(Talk) 01:41, 2 January 2012 (UTC)

This pages reads like propaganda. The first two sentences; "Sea levels are rising. Current sea level rise potentially impacts human populations (e.g., those living in coastal regions and on islands)[1] and the natural environment (e.g., marine ecosystems).[2]" read like a political statement and not a scientific statement. Not that I am suprized in the least since most of these pages read like propaganda, but this one is one of the more blatent about it.

A little reasearch on the second statement is a pretty big unknown. While there is a potential, none of what I saw linked to that statement say anything specific only that more research is needed. The second statement also does not pass the smell test. As a diver, the current stated increase of a couple of mm per year, is not consistant with an ecosystem that spans tens of metres of water column, and is affected by daily variation of several feet. Coral's, tunicates, and sponges (which would be most impacted by any rise) also span several metres of water column. A rise of several feet on average over a short period of time would have an impact, but the small rise claimed simply will not, and the sources do not make such a weighty statement. Arzel (talk) 16:50, 2 January 2012 (UTC)

When can we expect some draft edits for suggested improvement? NewsAndEventsGuy (talk) 16:56, 2 January 2012 (UTC)

It's no good changing the lede, which summarises the article, without first changing all the facts and figures quoted and referenced in the article body. That will be no mean feat. I don't see how a summary of scientific research can be characterised as "political" "propaganda", unless the definition of political debate gives credence to an extreme anti-science, and anti-rational, stance. This diagram shows an interesting and relevant summary, I think. --Nigelj (talk) 17:09, 2 January 2012 (UTC)

Actually i believe that Arzel is at least partially correct. Who ever cited the natural environment part, confused sea-level rises with generic climate change impact. (wrong section in the IPCC!). And the sentence is actually not a summary of any part of the article. --Kim D. Petersen (talk) 18:44, 2 January 2012 (UTC)

OK, that may be a good point. I was responding to the wider criticism at the start of the original comment. On the specific point of rising sea-levels' effect on marine ecosystems, I did find these in the cited IPCC ref:

• "Impacts: Climate change can impact marine ecosystems through ocean warming (Wang et al., 2004b), by increasing thermal stratification and reducing upwelling (Cox et al., 2000; Sarmiento et al., 2004a), sea level rise (IPCC, 2001) [...]"
• "A predicted sea-level rise of 0.5 m will eliminate up to 32% of sea-turtle nesting beaches in the Caribbean (Fish et al., 2005)."
• "Additionally, at least some populations of this [bird] species could also lose critical migratory stopover habitat (Delaware Bay, USA) to sea-level rise (Galbraith et al., 2002). [...] Many of these [bird] species also winter in coastal areas vulnerable to sea-level rise (Inkley et al., 2004)."
• "Extensive loss/conversion of habitat in Kakadu wetland due to sea-level rise and saltwater intrusion"
• "Other climate change factors (such as sea-level rise, storm impact and aerosols) and non-climate factors (such as over-fishing, invasion of non-native species, pollution, nutrient and sediment load (although this could also be related to climate changes through changes to precipitation and river flow; Chapter 6, Box 6.1; Chapter 11, Box 11.3; Chapter 16)) add multiple impacts on coral reefs (Chapter 16, Box 16.2), increasing their vulnerability and reducing resilience to climate change (Koop et al., 2001; Kleypas and Langdon, 2002; Cole, 2003; Buddemeier et al., 2004; Hallock, 2005)."

I don't know if these can be considered enough to warrant that clause in the lede. Maybe these points need including better into the body first, as per my original post here. --Nigelj (talk) 19:25, 2 January 2012 (UTC)

Regarding Sphilbrick's removal of a "page" needed tag, with the edit summary: "Page number not needed, the site linked doesn't even have page numbers, and the refernce to the table number is more precise, in any event" – I have reverted it.

In the first place, specific location within a source is needed for WP:V. That the IPCC report cited does not have page numbers in its html version is why section numbers (and titles) are preferred, but lacking a {{section needed}} or even {{specific location neeed}} tag, I sometimes make do with "page neeeded". (Which would suffice, as checking the page in the pdf would give the section.) Yes, linking to the table is specific, but we should also link to the context.

This instance is easily remedied, but I point it out so the general situation is understood. ~ J. Johnson (JJ) (talk) 22:25, 31 December 2011 (UTC)

In the first place, specific location within a source is needed for WP:V.

The Table number is highly specific.

You asked for a page number, it doesn't have a page number. If you want something else, you should ask for something else.

As I explained above: there isn't a {{section needed}} tag, so I made do with what is available. ~ J. Johnson (JJ) (talk) 23:57, 31 December 2011 (UTC)

There are no section numbers within the source. (it is section 3, but that refers to the entire link, so that number doesn't serve to narrow down the search).

For sure, the link needs to be split. See below. ~ J. Johnson (JJ) (talk) 23:57, 31 December 2011 (UTC)

If you can identify a better way to identify the table, by all means do so, but a reference to the first table in the site seems hard to beat.

I request that you revert your own reversion, as you have provided no coherent rationale for your tag.--SPhilbrick(Talk) 22:35, 31 December 2011 (UTC)

Eventually I'll make another pass through there and clean-up several related problems. Leaving the tag in will help me (or anyone else that wants to fix it) locate the problem. ~ J. Johnson (JJ) (talk) 23:57, 31 December 2011 (UTC)

FYI, I work with IPCC documents in PDF form saved to my hard drive. I could find a table by table number, but page numbers are very convenient. NewsAndEventsGuy (talk) 22:40, 31 December 2011 (UTC)

So do I, but how would we know that your PDF version pages the same as someone else's? Other than the silly observation that this is the first table so it is probably page 1, but in general, I don't believe PDF page numbers are unique. It certainly doesn't help me find a table if someone tells me it is on page 20 of a PDF on someone else's hard drive, when the same document save by me might have it on page 18, or page 24. but the Table number is always the same. If the citation was to a fixed PDF which had page numbers, then page numbers would be helpful, but that isn't the case here.--SPhilbrick(Talk) 23:27, 31 December 2011 (UTC)

Unless there's some magic I don't know about, PDF pagebreaks are part of the original file and are not influenced by any settings on the system that is downloading the file. I was refering to the page breaks that come with the official PDF file provided at the IPCC website. True, they might sometimes change the file to account for errata and the like. But in 2012, I doubt that is happening much with the 2007 and earlier reports. NewsAndEventsGuy (talk) 00:05, 1 January 2012 (UTC)

Is your PDF for A4 or for American Letter? (it makes a difference). --Kim D. Petersen (talk) 00:55, 1 January 2012 (UTC)

The authority for a page number is the printed version of each report, which should be faithfully shown in the page image in your pdf. As to the pdf-page numbering, well, AR4 (and I believe TAR, but don't recall just off hand) cleverly synchronize that with the printed pagination. But if there should be a discrepancy, the page number of the printed version is controlling. ~ J. Johnson (JJ) (talk) 00:10, 1 January 2012 (UTC)

This is close to tendentious. The information is located at the end of the link... It is verifiable by anyone - thus adhering 100% to WP:V An excuse such as "its to remind myself" is certainly not acceptable. But if you really really really want to know the page in the SPM - it is page 8. If this is the result of adhering to a "new standard" for IPCC citations - then it has gone out of control. --Kim D. Petersen (talk) 00:52, 1 January 2012 (UTC)

I think a better word is "implicit" rather than "tendentious". The thread implicitly drifted beyond this one citation and got into JJ's broader efforts at standardizing IPCC citations. For that broader scope, I agree we should use the printed number on the page, and not the number in the PDF reader toolbar. On the other hand, I also think the purpose is to help people find info. Standardizing the format is a great help and something of a thankless task. (Thanks JJ) On the other hand, once it is set up, little form discrepancies here and there are no big deal, and that is especially true for any article that gets under 200 hits per day, which is the vast majority of climate articles. NewsAndEventsGuy (talk) 02:57, 1 January 2012 (UTC)

You are welcome. Perhaps everyone needs reminding that this thread started with my explaining the seemingly illogical use a page needed tag for a source that, at one level, does not have pagination. And it's only temporary. ~ J. Johnson (JJ) (talk) 01:02, 3 January 2012 (UTC)

I haven't forgotten, nor have I seen a cogent argument in support of the need for a page number for a document without page numbers.--SPhilbrick(Talk) 01:06, 3 January 2012 (UTC)

Then I shall explain it again: the document has page numbers, just not the on-line html version. So while a page number is suitable for print and pdf versions, specification of the section would, indeed, be more appropriate. But there is no {{section needed}} tag, so I used the page needed tag. I some cases I have also inserted a comment explaining that, and rather wished I had done so in this case, as it would have saved a lot of trouble and time. ~ J. Johnson (JJ) (talk) 01:29, 3 January 2012 (UTC)

Repeating a flawed argument doesn't help—the entire source is a single section of the report, so adding a section number is silly. What do you propose should be done? I propose removing the useless tag. What do you propose?--SPhilbrick(Talk) 01:51, 3 January 2012 (UTC)

Unless some bot would kill this approach, I'd just use {{section needed}} "template" and say "see talk section 'section needed tags'" in the edit summary. Then you could explain this again.... but hopefully for the last time. Sphil.... those who look at this reference via html in a browser are likely to navigate via section number. Those who use pdf or hardcopy are likely to use printed page number (as it appears in the page footer). I do both. Its the same reference, just packaged in different formats. JJ has come up with a pretty nifty way to enable both groups of readers to follow our citations with ease. NewsAndEventsGuy (talk) 02:14, 3 January 2012 (UTC)

A tag implies that some information is missing, and can be supplied if someone would just track it down. I don't think that's the case here. I don't think we should have a maintenance tag for something that is inherently unfixable. What purpose does it serve, other than to waste the time of editors who might be working on an article? I know JJ has bones some nice work on standardizing the reference canon. I applaud that work. But need I quote Emerson? I propose removing the tag as it serves no useful purpose.--SPhilbrick(Talk) 02:21, 3 January 2012 (UTC)

You said:

those who look at this reference via html in a browser are likely to navigate via section number.

Why do you think this is true? If you click on the link, the Table is right there. Why on earth would you search for a section number when the Table is in front of you. If you are used to the pdf, you probably know the table anyway, or are familiar with the document already, and know how to find the table. This table is identified more specifically than 99.99% of all references, and you are begging for a less specific reference item. This makes no sense, and I can't believe so much time is being wasted in this. Do you remember the kid's joke about the executive who asked his assistant where his pencil was? When she replied, "behind your ear", he retorted, "I'm a busy guy. Which ear?" You guys are trying to specify which ear of a one-eared guy. Why?--SPhilbrick(Talk) 02:29, 3 January 2012 (UTC)

I also laud that JJ attempts at consolidating IPCC links.... but in this case it is ridiculous, and as said earlier tendentious. If a link goes directly to the information (on a reliable source) that verifies the information, then WP:V adhered to in full.... and requiring information beyond that is certainly not a tagging issue. --Kim D. Petersen (talk) 16:28, 3 January 2012 (UTC)

Kim, Setting the tagging issue aside, do you have any objection to having both a section/figure/table number as well as a pdf (or hardcopy) page number for IPCC citations? If you don't mind that, then is the your objection here based only on the fact that these tag(s) temporarily clutter up article(s)? If that is the only concern, could you abide any time with the tags to accommodate a work in progress, or are you arguing from a tag-zero-tolerance perspective? Nothing emotional here, just trying to assess the exact bounds of the issue(s). NewsAndEventsGuy (talk) 18:10, 3 January 2012 (UTC)

I'm not following why you say Temporary, and I'm pushing this partly because it might mean that I'm missing something. That site is never going to have a page or section number, so why is the tag temporary? I'm in favor of tags that indicate a problem with a possible resolution; this one sounds like a request for information that simply doesn't exist. Again, I'm asking because you said "temporary" which leads me to wonder if I fully understand.--SPhilbrick(Talk) 19:24, 3 January 2012 (UTC)

Apparently not. Kim already told us the page number is 8, contrary to the facts you state. Kim, what about those Qs I asked you? Is temporary page clutter the only objection/issue you have with JJ's approach? NewsAndEventsGuy (talk) 20:00, 3 January 2012 (UTC)

The tags are the issue here - and they are entirely inappropriate, when the citations are compliant with WP:V. But talking in general, the more metadata that is available - the better. --Kim D. Petersen (talk) 20:10, 3 January 2012 (UTC)

Thanks for the reality check. JJ, in the future, instead of article tags IN READ MODE how about placing some sort of indexing label in a hidden inline comments, and then adding a to-do list indexed with those labels on the talk page?NewsAndEventsGuy (talk) 21:38, 3 January 2012 (UTC)

Among the main reasons discussions like this often get tendentious are 1) people not paying attention to what has been said, and 2) multiple issues being introduced pell-mell. As to the latter, I don't mind (generally) trying to address every particular issue someone may have, but it would be better to take them up one at a time, deal with them, and then leave them in order to move on. So here are issues raised so far, and my responses (one or more for the third time).

1) Compliance with WP:Verification, particularly regarding pagination and such. I quote: "The citation should fully identify the source, and the location within the source (specifying page, section, or such divisions as may be appropriate) where the material is to be found.". Now this has been subject of some controversy, where many editors think a bare url is "good enough", or that merely waving at some source is close enough. I suspect many of you attending this discussion have not done much verification, or you would be demanding as specific citation as possible. I am minded of another discussion (re Harv) where much was made of making things easier for the editor that writes, but there seems to be practically no regard for making things easier for the editor (or reader) that wants to verify. I remind you all the verification is one of Wikipedia's core content policies, that the key to verification is proper citation, and that there are standards for proper citation (both within and without WP) – OF WHICH THIS AND OTHER ARTICLES FALL SHORT. The bottom line: all this grief complaining about a page number tag would have been better spent supplying the page number.

2) The source doesn't have a page number, and therefore the alleged problem is inherently unfixable. Simply wrong on the facts. The document – as published by the Uhiv. of Cambridge Press in print format, and available on-line in pdf format, both of which are referenced by editors here – has page numbers. (And, as NAEG pointed out, Kim has supplied the an actual page number.) It is the on-line html version which lacks page numbers, which is why section number and title are preferable.

3) "Section needed" would be more appropriate. Unfortunately, we don't have a {{section needed}} or even a {{specific location neeed}} tag; I used what was available. (The time spent on this discussion is almost sufficient to have made such a tag.) Though I rather like NAEG's suggestion of just using the red-link "tag", and will consider it in the future.

4) The table url is specific enough, and begging for a less specific reference item. I agree the table url is specific, but why is it objectionable to augmenting it with additional metadata? Along the same lines ISBN is sufficient for a book, so why bother with title, etc.? My self, I think there should be more context (metadata), like which section the table is in. Certainly it is well to have a url that goes straight to a table, but often these go to separate pages. So as a general rule I include more context. Why is that a problem?

5) Tags not temporary. Only if the problem tagged is "inherently unfixable", which I have disproved (see above).

Hopefully that settles those points, and any continued discussion can find new points. (I believe Kim has some outstanding concerns?)

NAEG has suggested that in the future I could could setup a list in the Talk page with links to any problems. That is an interesting idea, but I am thinking not: that's what the tags are supposed to do, and it would a lot of work better spent on the problems themselves. I would point out that I am not trying to make anything perfect, just better. And where I should ask to make one small thing better, why is there all this grief?

~ J. Johnson (JJ) (talk) 02:36, 4 January 2012 (UTC)

My response really should have been WP:TLDR.....

Repeating assertions that have been addressed before, does not make your arguments better. Your #1 is simply a false wiki-lawyer(ish) "interpretation" of WP:V. #2 is a strawman (based on #1). #3 is another strawman based on #1. #4 is yet another strawman - no one is against augmenting it - just don't tag it! #5 is irrelevant, since the tags are based on a false assumption.

You simply continue on the same tendentious route as before. --Kim D. Petersen (talk) 06:41, 4 January 2012 (UTC)

I wish I had read Kim's response first, and saved myself the time I spent reading. I agree with Kim's response, and won't repeat the points. You say "The document – as published by the Uhiv. of Cambridge Press in print format, and available on-line in pdf format, both of which are referenced by editors here – has page numbers." That some other document has page numbers is not relevant. If consensus supports changing the citation to a different source, one with page numbers, go for it. I don't see a page number of the source cited. I've made mistakes, before (and currently, as I keep typing), so if the pdf cited here has page numbers, please tell me where I can find them. I don't see them. (I think Kim's response that this is page 8 refers to a different version of this report.)--SPhilbrick(Talk) 12:10, 4 January 2012 (UTC)

Ambiguity alert. Since the section is being currently edited, I don't know for certain which cited source's link you are referring to, and more specifically I want to make sure when I click to try to answer you that I call up the same url. Please clarify. NewsAndEventsGuy (talk) 13:32, 4 January 2012 (UTC)

Footnote 11, which links to this which now says page 8. Can you point out where I find the page number?--SPhilbrick(Talk) 16:08, 4 January 2012 (UTC)

That's a perfect example. We linked to the version, which as you correctly note does not have page numbers. However, if you instead download the pdf version, which you might have found at the top-level TOC on the IPCC webpage for the SYR portion of AR4, then you will find the table on page 8 of the pdf.... but don't look at page numbers in your reader toolbar, look at the page numbers in the page footer on the document itself. NewsAndEventsGuy (talk) 17:02, 4 January 2012 (UTC)

I've split NAEG's last comment into a subsection, as I think the question of tagging in general would be better addressed separately.

I see that Kim has fixed the citation I originally tagged. Not in the way I would do it, but so what? The specific problem has been addressed. (Thank you, Kim.)

But I am quite disappointed about Kim's "a false wiki-lawyer(ish) "interpretation" of WP:V." What I quoted clearly states: "fully identify the source, and the location within the source". How is my interpretation false? And it is hardly wikilawyering to point out what the policy actually says.

Issue #2 is hardly a strawman argument when it is the explicitly stated basis by which the tag was removed.

Kim's general view seems to be that not only does WP:V not require fully identifying the location within the source (a view I dispute), but also forbids any tagging that requests such a location. (And note that a tag is only a request, no one is forced to respond.) I find that bizarre, but this entire topic seems to be too sensitive for many folks, so perhaps further discussion woudl be futile. ~ J. Johnson (JJ) (talk) 21:45, 4 January 2012 (UTC)

IPCC AR4, Synthethesis Report, Summary for Policymakers, Table SPM1 is a 100% complete and fully indentifying citation. It isn't in any way or form ambiguous, it points you directly at the reference and specific location, that you cite, and for the verifier it presents no problems. That you personally would like the citation to contain more information is your personal preference. Links are sugar with respect to WP:V, specific pages are sugar unless the citation is difficult to find, sections are nice, etc etc.

Your Wikignomish work is appreciated, but your obsession with having your own personal views enforced to the detriment of the actual article, is not. I am btw. not amused about your attempt at mindreading, despite its 100% failure in success. --Kim D. Petersen (talk) 22:55, 4 January 2012 (UTC)

It is because I am not a mind reader that I was trying to clarify my understanding of your view. As to personal preferences, mine is that Wikipedia be the best that we, collectively, can produce. Which has implications regarding citation practice, though I would argue that my particular preferences here – of correctness, clarity, consistency, and even (though some of you folks don't accept it) ease of editing and conformance to policy – are no less valid for being what I have adopted as preferences. I suspect that the real issue here is this concern that people might be forced to alter familiar practices. This seems too sensitive for fruitful discussion. ~ J. Johnson (JJ) (talk) 01:12, 7 January 2012 (UTC)

As has become a habit to you, you suspect wrong (don't take a job as a mindreader!). I very very very very very very very very very very very very much care about citations, consistency, clarity, correctness! Most of what i've done on Wikipedia is wikignome work: checking facts, verifying citations, adding citations, correcting citations etc. etc. But i never would let clerical work take precedence over presenting the real information (you know: the encyclopedic ones). And tagging for pure clerical reasons is such. --Kim D. Petersen (talk) 01:57, 7 January 2012 (UTC)

I have changed my mind and no longer support visible tagging, specifically for.... a redundant cite to a different version of the info, after the first is fully cited. Collecting and inputting the metadata is clerical work. It is not vital, but a nice dotting of the I's. Since hidden inline comments afford JJ a reasonable alternative means of reminding JJ, the only reason for visible temp tagging is to recruit clerical help in dotting the Is. It's a nice hope that folks would say "Hey yeah, I'll pitch in!" but in reality I think it works more like "What's this crap?? Seriously? OK, I'll look up the page/section number just to clean this junk up. Sheesh." Meanwhile, the temporary tag could give a casual reader the false impression there is something "wrong" with the tagged statement. What made me change my mind is the negative impact of that probable psychology (though I done any usability testing data to support my hypothesis)!

In contrast, an inline comment is sufficient, with downside only that editor who placed it and any who stumble across know about it. An optional antidote is a teensy bit of extra clerical work of placing a tickle in the talk page "Article has inline hidden comments starting with 'To complete citation...'. Please help by searching for that text and completing the citations." It doesn't recruit (force?) clerical assistance as much as a visible tag, but it will get the job done. I might add that the incremental extra work will likely be less than the cumulative time spent on this thread. NewsAndEventsGuy (talk) 08:28, 4 January 2012 (UTC)

This section in a nutshell: At least one editor thinks that because the qualifier "at least" for the range of sea level rise is not explicitly stated verbatim in the pinpoint, section-specific citation to IPCC AR4 (2007) it should be removed, whereas at least one other editor thinks the pinpoint citation uses other words to convey that meaning consistent with the entire reference overall. The latter editor thinks the implied qualifer "at least" is so abundantly clear that omitting it here risks miscommunicating the intended meaning of the source, but upon further review of the evidence, decided that removal was warranted

The work on improving the references has been positive, however, the edit improving the reference also added a qualifier to the projection range. Unfortunately, the qualifier is too strong. I don't believe the qualifier is accurate for more than one reason:

• The least important reason is that it isn't true. The statement, as written, implies that sea level rise cannot possibly be less than 18cm. I grant that it is highly unlikely to be less, but that's not what the statement says. I don't want to dwell too much on this, because WP is about V not T. Let's move on to what the sources say.
• We know that the IPCC is performing scenario analyses, because that's what they say. They do not go into a lot of detail about what it means to do scenario analyses, because this approach is so ubiquitous, that it doesn't need complete explanation in every discussion. Scenario analyses almost never cover all possible outcomes. It is almost never possible to make absolute statements about outcomes outside the extremes of the most extreme ranges, especially in the physical sciences (in math and logic, it is easily possible to design scenarios covering all possible outcomes). In the physical sciences, with the possible exceptions of low temperatures, and high speeds, one can never exclude outcomes outside the ranges. (With temperatures, absolute zero is a solid lower bound, with speed, the speed of light is usually a good upper bound, but even that is under challenge recently.) It doesn't need to be stated that outcomes below the lower bound of the range of a scenario are possible, because it is virtually always true. If the IPCC viewed this as an unusual exception, they would have stated so. The do not state that it is impossible for sea level rise to be less than 18 cm so we are wrong to impute it. Saying it might be a violation of SYNTHESIS if one could impute it from their words, but I don't even think that is valid.

I thought this would be straightforward, but I was wrong. In an exchange on my talk page, an editor said:

I know this isn't the right place, but I'll post my reply here as a "head's up", and if you take it to the article talk page, please copy and paste this comment since I would say the same thing anyway. Throughout the SYR portion of the AR4 report, in many places, they project numbers and then assign likelihood to those numbers. Please check this specific section (SYR 3-2-1), and don't just look at the table we were talking about in the thread before. Instead, please read the whole page. Note that IPCC says "this report does not assess the likelihood, nor provide a best estimate or an upper bound for sea level rise." (bold supplied) They did not hedge their lower boundary. In law, calling out one term for special treatment but not the other is typically read to say something about both. See also WG1's summary section on sea level projections. In that section they also talk about even higher rates being possible "Further accelerations in ice flow of the kind recently observed in some Greenland outlet glaciers and West Antarctic ice streams could increase the ice sheet contributions substantially, but quantitative projections cannot be made with confidence" Nowhere do I find any suggestion that they thought flows could reduce below whatever rate they used in their projections. (I saw that defined once, but don't remember what it was). Elsewhere, they discuss carbon-cycle feedbacks, and while some are indeed negative, IPCC is generally talking about net warming (which would lead to more thermal expansion and more melting). Again, no nibbles at that lower number, just the upper one. So IMO it accurately reports what IPCC said when I wrote "at least....but the numbers don't include....(two things that throughout the WG1 report are only discussed in terms of staying the same or increasing)". With no science suggesting those unknowns will fall, "at least" is an accurate presentation of the IPCC report.

Also, while citing the IPCC report, the New Zealand ministry of environment web page says "Other consequences include more extreme weather events, like floods, storms, cyclones and droughts, and estimated global sea-level rises of at least 18 to 59cm". [8]. For fun, try the following search string at (A) google and (B) Google-scholar

IPCC "sea level" "at least 18cm" OR "at least 18 cm" OR "at least 18 to 59" OR "at least 18-59" "

NewsAndEventsGuy (talk) 17:27, 5 January 2012 (UTC)

The report adds qualifiers for reasons I think all readers here know well. The scenarios that were constructed specifically excluded a potential major issue—the possibility of increased ice sheet flow. If this occurs, it would affect the upper bounds, so they have included a caveat regarding the upper bound. It is improper to make the legalistic argument that a discussion about the possibility that the upper bound could be breached implies that the lower bound is absolute. This would not only be SYNTHESIS, but false SYNTHESIS, as it does not follow. Indeed, when the report talks about ice flow, they note they are using average rates, they state "The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993-2003, but these flow rates could increase or decrease in the future."[emphasis added].

I note that NewsAndEventsGuy has a cite from a New Zealand governmental source using the wording. If it is the consensus of editors that we should use a government site rather than a scientific site to make scientific statements, even when those statement are scientifically wrong, I'll accept the consensus, but we should specifically cite the flawed wording to the New Zealand site, so there is no confusion about the source.

Seriously, I propose that we modify the wording to remove the incorrect qualifier. Can we discuss whether there is a good reason to include this incorrect qualifier?--SPhilbrick(Talk) 13:10, 6 January 2012 (UTC) ::: Sphil, before I reply to your arguments here, I have a QUESTION... did you do the Google-scholar search I suggested before posting here? NewsAndEventsGuy (talk) 14:46, 6 January 2012 (UTC) nevermind, Today I don't see what I thought I saw when I suggested that. Cryptic enough for you? My apologies, I don't know why I thought yesterday that there was a such a ton of such resounding stuff that it just must confirm my text (self-denigrating sarcasm intended). Today it looks scant. I'll answer more fully later today or the weekendNewsAndEventsGuy (talk) 15:24, 6 January 2012 (UTC)

I hate to be wrong, but you have persuaded me that "at least" is too simplified. Thanks for explaining your reasons with some facts, not just opinions or platitudes.

Happens to the best of us, and happens to me as well :)--SPhilbrick(Talk) 14:36, 7 January 2012 (UTC)

Of particular interest as I tried to dig deeper was this and this and this. NewsAndEventsGuy (talk) 10:49, 7 January 2012 (UTC)

Thanks for those links, all very interesting. --SPhilbrick(Talk) 14:36, 7 January 2012 (UTC)

^[1] removed with criticism but without a better source...? 108.195.138.200 (talk) 09:25, 10 April 2012 (UTC)

Thanks for contributing! We typically don't wikilink the lede (why it seems to be so here is unclear). I don't have a good modern sea level reference off the top of my head. The article that you cited used a single data point, and single areas can be subject to subsidence and other factors, and the article was poorly done. On Wikipedia, it is the responsibility of the contributor to make sure that their contributions are up to standards; while I usually find a replacement reference or something, I am short on time and think in this case that the rest of the article supports the statement (as should be the case for the lede). Awickert (talk) 00:21, 11 April 2012 (UTC)

The OP is an IP sock with a long record of external link spamming, block evasion, and after the block was erroneously allowed to expire (clock should have been reset for each block evasion but was not) they are now doing the bare minimalist editing to strew external links throughout the articles. Their editing is clearly not designed to improve the articles, just the merest thread to get them past the easily demonstrated intent of external spamming. Ironically, the IP's links are supportive of the mainstream assessment of climate science, but their editing behavior weakens our articles because they are driveby posts, not the result of careful reading and thought. Anyone wants to make a formal complaint about my allegations, let 'em. I would love to have this IP sock before a formal ANI proceeding. NewsAndEventsGuy (talk) 18:41, 11 April 2012 (UTC)

Thanks for the info; I've been away for a while. I wasn't lying about the time constraints, though: no chance of me doing anything administrative on Wikipedia. Awickert (talk) 07:30, 12 April 2012 (UTC)

The section on glaciers and ice caps says "High-precision gravimetry from satellites in low-noise flight determined that Greenland was losing more than 200 billion tons of ice per year." In an article concerning sea level, it is not the mass of ice which is of interest to the reader, but its corresponding sea level change. I added a clause indicating that the 200 Gt is 0.6 mm sea level equivalent, but this change was rejected saying that a reference would be required. This is surprising, as the conversion is neither difficult nor controversial. In fact, in this very article the Antarctic mass loss rate is given as "50 Gigatonnes of ice per year ...(around 0.14 mm of sea level rise)." Quadrupling the values, one can deduce that the sea level equivalent of 200 Gt is 0.6 mm, to one significant digit. If more evidence is needed, Velicogna's 2009 paper^[2], which apparently is the source of the Greenland figures, at one point gives an equivalence of 373 Gt (Greenland plus Antarctica) to 1.1 mm of sea level rise, from which again one can derive that the sea level equivalent of 200 Gt of ice, is 0.6 mm (again, to one significant digit). So I ask why the proposed change is not appropriate. LijeBailey (talk) 01:00, 25 April 2012 (UTC)

I have reverted Lfsteven's receent mass conversion because of some very dubious changes. I would not quibble whether "background" should be "lightgray" or "lightgrey". But decapitalizing acronyms is flat-out wrong, and undermines the credibility of all associated changes. So I reverted it. ~ J. Johnson (JJ) (talk) 21:24, 12 June 2012 (UTC)

I quickly scanned the changes before you reverted, and didn't notice anything leap out at me. Which acronyms were you referring to? NewsAndEventsGuy (talk) 23:08, 29 June 2012 (UTC)

All of the "IPCC AR4 WG1" => "Ipcc ar4 wg1" conversions at the bottom of the list. And as the "lightgrey/lightgray" (or was it the other way around??) changes were flat out trivial I reckon these changes as a whole were pointless, and not worth the time or trouble of trying to salvage any particulars. ~ J. Johnson (JJ) (talk) 20:56, 30 June 2012 (UTC)

I'm seeing notes of sea levels during the early Holocene that may have been higher than today, rather than a gradual increase. Perhaps a South African Study. Pehraps this should be added to the page. http://wattsupwiththat.com/2011/01/05/on-%E2%80%9Ctrap-speed-acc-and-the-snr/ http://wattsupwiththat.files.wordpress.com/2011/01/compton-2001-holocene-sea-levels.jpg http://www.geo.arizona.edu/palynology/geos462/01histplist.html http://www.geo.arizona.edu/palynology/geos462/sealvl3.gif Keelec (talk) 20:15, 4 July 2012 (UTC)

• When legislators stick their heads in the sand, they might just drown. Poor North Carolina. June 8, 2012 Skeptic (U.S. magazine)

108.73.113.91 (talk) 06:53, 6 July 2012 (UTC)

Dumb political actions seem rather irrelevant here - maybe write it up for the NC legislature article :) Also, note that it is a blogpost and too many ext links already. Vsmith (talk) 02:00, 8 July 2012 (UTC)

Agreed it is dumb politics. What about http://www.nccoast.org/m/article.aspx?k=46f88670-10f4-4991-a1aa-1f1320ee5860 for the Politics and government of North Carolina? 99.181.159.214 (talk) 02:21, 8 July 2012 (UTC)

Special:Contributions/Vsmith you still here? 108.195.138.75 (talk) 06:09, 16 July 2012 (UTC)

In the lede, I've revised the following sentence:

"Although IPCC explicitly refrained from projecting an upper limit of total sea level rise in the 21st century, one meter of sea level rise is well within the range of more recent projections."

The cited source (US NRC, 2010) does not emphasize 1 m of sea level rise. Rather, the source cites a range of projections, e.g., "Horton et al. (2008) estimates a sea level rise of 2 to 2.6 feet (0.62 to 0.88 meters) by 2100." In my opinion, it is more balanced to refer to the full range of projections that they assessed. My revised sentence is:

"More recent projections assessed by the US National Research Council (2010)^[3] suggest possible sea level rise over the 21st century of between 56 and 200 cm (22 and 79 in)."

Enescot (talk) 04:38, 11 December 2012 (UTC)

In the introductory session thermal expansion is listed as a 'main factor' of sea level rise, it is then never mentioned again, leaving the reader with no idea what proportion of past or forecast sea level rise is due to thermal expansion. — Preceding unsigned comment added by 195.173.80.1 (talk) 13:35, 28 December 2012 (UTC)

This is from the current article: "From 1950 to 2009, measurements show an average annual rise in sea level of 1.7 ± 0.3 mm with satellite data showing a rise of 3.3 ± 0.4 mm from 1993 to 2009". This sentence states that the average annual rise from 1993 to 2009 was on the order of 0.2 mm. Is this correct, or is the sentence quoted missing an "annual"? It appears I can't check the source myself. 129.16.121.34 (talk) 16:36, 23 January 2013 (UTC)

Yes, "mm/year" (a rate) was left as "mm" (absolute); thanks for catching that. I've fixed that, but someone with access to "Geophysical Research Letters" ought to check the preceding sentence for a similar error. ~ J. Johnson (JJ) (talk) 23:52, 23 January 2013 (UTC)

I know enough about climate change and geology not to mess with an article well written by experts. Could someone have a look at this BBC article as if I read it right there is now consensus albeit with a large degree of uncertainty. JRPG (talk) 12:57, 1 December 2012 (UTC)

"finally quantifed" is far too precise. But the article is worth using William M. Connolley (talk) 18:19, 1 December 2012 (UTC)

Question from Brian Sandle Apr 29, 2013: Need to see comment on subsurface melting of non-glacial parts of ice sheets. Since water has less volume than the ice it comes from such melting would seem to lower sea level, masking rise from glacial feed melting. Soundhill (talk) 03:51, 29 April 2013 (UTC)Brian Sandle

See Archimedes principle. LeadSongDog come howl! 05:02, 29 April 2013 (UTC)

A floating body displaces its own weight of the liquid in which it floats. I think that there ought to be better names to more easily distinguish the floating "shelves" from the "sheets" which is the name for the ice sitting on land or maybe sea floor, so not floating? 111.69.244.232 (talk) 08:39, 29 April 2013 (UTC)Brian Sandle

A number of recent edits by David.moreno72 and anonymous IPs are both questionable in content and have broken or incomplete citations. I suggest a rollback to Rubin's edit of 09:39 14 April. If any of the offending parties come by I would remind them 1) that urls are not adequate citations, and 2) of WP:CITEVAR regarding consistency of citation format. This article has a consistent citation style, please try to stay in tune. Ask if you have questions. ~ J. Johnson (JJ) (talk) 17:44, 24 April 2013 (UTC)

Thanks for your pickup. I think a rollback would be a little excessive as I think I have made some useful constructive edits and corrections so that the data now matches the references. Hopefully I have made the corrections in line with the citation format. Regards David.moreno72 (talk) 03:50, 25 April 2013 (UTC)

I think some of the content of your edits is questionable, but I'll leave that for others to examine. Regarding the citations, check (current) note 48: red error! This is ultimately due to sloppiness in your use of the citation parameters. E.g., mixing "last" and "author". (Other citations in this article are also sloppy, which is to say that the article is a mess and doesn't set a very high standard, but actual errors are substandard.) I strongly recommend that you use "first1", "last1", first2", "last2", etc., and reserve "author" for cases where first/last are not suitable, such as works by a group or organization. Taking care in this regard will avoid a number of possible errors. Also, "coauthors" should generally be limited to where there are more than eight authors. ~ J. Johnson (JJ) (talk) 18:57, 25 April 2013 (UTC)

BTW (if anyone else is watching) there still are the other IP edits which perhaps should be checked. ~ J. Johnson (JJ) (talk) 19:07, 25 April 2013 (UTC)

Scientists in 1990 observed a rise of 1mm /yr; global average

Scientists in 1995 observed a rise of 1mm /yr; global average

Scientists in 2000 observed a rise of 2mm /yr; global average

Scientists in 2005 observed a rise of 3mm /yr; global average; noting the surprisingly rapid acceleration

Scientists in 2010 observed a rise of 5mm /yr; with the east coast of the US rise greater than elsewhere

Scientists in 2015 expect to observe a rise of 8 mm /yr with the east coast of the US rise greater than elsewhere

Those observations could be extended or modeled as a Fibonacci or exponential curve

far in excess of the IPCC worst case analysis well before the end of the century

12.187.95.191 (talk) 11:59, 13 December 2012 (UTC)

If you had quoted any reliable sources, I'd have been with you. Right up to the point where you predicted what scientists will observe in 2015. Is that a Mayan prophesy, a time machine, or an extrapolated curve that you're using for that part? --Nigelj (talk) 15:22, 14 December 2012 (UTC)

---

The last part of the first paragraph is rather unclear, and perhaps not fully in accord with the sources. I suspect it is trying to say that 1) sea-level has been increasing in recent times, 2) the increase is continuing (i.e., it is not a decadal variation), and 3) the rate of increase is also increasing. If that is the case, perhaps someone would like to check the sources, and do some copy-editing? ~ J. Johnson (JJ) (talk) 23:06, 23 December 2012 (UTC)

The most important points are

the 2014 IPCC report is expected to show the rate of increase is far in excess of the IPCC worst case analysis from 2007

the rate of increase is observed to be increasing at an increasing rate; ie exhibits acceleration

the rate of increase is not increasing uniformly so in some places like the East Coat of the US its much worse

the sequence 1,1,3,5,... is a fibonacci series with the next term extrapolated as 8; ie; the increase is exponential

if sampled by decade it would be 1,2,5,... with the next term coming in 2020 expected to be 13

there is a connection to warming which is also accelerating

there is some synergy between cause and effect as we trigger tipping points;

as we lose sea ice the albedo changes increasing the warming; methane hydrates are released, mediating organisms die off...

the observations can be easily checked by googling date and sea level rise

^[4]

12.187.95.227 (talk) 13:09, 11 May 2013 (UTC)

The 2014 report might be "expected" to say that, but it hasn't said it yet.NewsAndEventsGuy (talk) 13:26, 11 May 2013 (UTC)

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-5-1.html

"there is strong evidence that global sea level gradually rose in the 20th century and is currently rising at an increased rate, after a period of little change between AD 0 and AD 1900. Sea level is projected to rise at an even greater rate in this century."..."Estimates for the 20th century show that global average sea level rose at a rate of about 1.7 mm yr–1."..."since 1993, sea level has been rising at a rate of around 3 mm yr–1,"..."sea level is not rising uniformly around the world. In some regions, rates are up to several times the global mean rise, "..."Global sea level is projected to rise during the 21st century at a greater rate than during 1961 to 2003. Under the IPCC Special Report on Emission Scenarios (SRES) A1B scenario by the mid-2090s, for instance, global sea level reaches 0.22 to 0.44 m above 1990 levels, and is rising at about 4 mm yr–1."

If sea level rose linearly at 4mm a year for the next 87 years it would rise 3.48 m (11.31 feet) by 2100. That's bad enough, more than 100 East and Gulf Coast cities of more than 100,000 population will need more than sea walls and levees, their infrastructure will need to be relocated to higher ground over the next 25 years, which just using the reconstruction costs from Katrina and Sandy could easily be in the range of 150 Billion a year per city.

If as is now projected the rate of increase continues to rise at an increasing rate they will need to be relocated along with everything else back to the foothills of the Appalachins. — Preceding unsigned comment added by 12.187.95.227 (talk) 14:34, 12 May 2013 (UTC)

This IPCC report from 2007 confirms the rate of increase is increasing at an increasing rate by graphing it as an exponential curve.

In 2010 Working Group 1 issued a report which included discussions of framing how to discuss modeling future sea level rise

https://www.ipcc-wg1.unibe.ch/publications/supportingmaterial/SLW_WorkshopReport.pdf

"During the breakout group, there was an expression of concern regarding the definitions of terms, such as ‘instability’, ‘thresholds’, ‘non linear responses’, ‘positive feedbacks’ and ‘tipping points’ as applied to ice sheets. Similarly, much was made of the distinction between true ‘instabilities’ and processes that are merely subject to positive feedbacks, as well as issues concerning the timescales of forcing and response. We concluded that the term ‘instability’ is now being routinely applied to ice sheet processes that do not fit the strict mathematical definition of ‘instability’, but represent a raft of process types given above; this may be a ‘shorthand’ that is useful to communication of the broader issues. However, distinctions do need to be made; for example, some processes only have significant long term impacts on ice sheets if forcing is sustained (e.g., surface mass balance losses driven by increasing summer temperatures), whereas others really do imply instability, such that once an internal/external threshold has been exceeded, there follows an irreversible response. More correctly, we might term the collective issues as, ‘perturbations from which it is difficult to recover'

From the first abstract of the IPCC Workshop on Sea Level Rise and Ice Sheet Instabilities (p63) Records of Past Sea Level Change: Amplitudes and Rates Edouard Bar"during the acceleration called Melt Water Pulse 1A of the last deglaciation. During this event (Deschamps et al. 2009),the sea level apparently rose by several meters per century,"

(p 121)"Sea Level Rise Projections from Semi Empirical Models Svetlana Jevrejeva Proudman Oceanographic Laboratory, National Oceanographic Centre,United Kingdom The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) suggested 18 59 cm sea level rise by 2100 with an additional 10–20 cm on the upper limit associated with rapid dynamical changes in ice flow of the ice sheets (Meehl et al., 2007). Lately these IPCC numbers have been challenged with new estimates of 0.5–1.4m (Rahmstorf, 2007), 0.75–1.90 m(Vermeer and Rahmstorf, 2010), 0.8–2.0 m (Pfeffer et al.,2008), 0.8–1.3 m (Grinsted et al., 2010) and 0.6–1.6 m(Jevrejeva et al., 2010) sea level rise by 2100.The approach used by IPCC to estimate future sea level rise has been to model the major components of sea level budget: ocean thermal expansion and ice melting. However, the observational sea level budget is not yet closed;"

(p125)Causes of Recent Sea Level Rise in the East/Japan Sea from Satellite Altimetry and In Situ Data Sok Kuh Kang 1, J.Y. Cherniawsky 2, M.G.G. Foreman 2, Eun Jin Kim 11 Korea Ocean Research & Development Institute, Korea 2 Institute of Ocean Sciences, Fisheries and Oceans Canada, Canada

"The 9 year long T/P analyses reveal average trends of 5.4 ±0.3 mm yr–1 for all of EJS and 6.6 ± 0.4 mm yr–1 for the southern EJS. These are much larger than the global rates of 3.1 ± 0.4 mm yr–1 reported by Cabanes et al. (2001) and 2.8 ± 0.4 mm yr–1 by Cazenave and Nerem(2004). "

(p 153)Global, Regional, and Local Sea Level Rise on the U.S. Atlantic Coast- Atlantic City as the New Atlantis? Kenneth G.Miller,Sr.1, Peter J.Sugarman 2, and James V.Browning11 Department of Earth and Planetary Sciences, Rutgers University,USA2 New Jersey Geological Survey,USA

There are hundreds of other abstracts from this 2010 report which will be in the 2014 report

12.187.95.227 (talk) 15:49, 12 May 2013 (UTC)

Looks like a barrage of quotes without specific article improvement suggestion. See also WP:WALLOFTEXT (which are generally unpersuasive). If you wish your ideas to get serious consideration please use a WP:SANDBOX to draft some text you would like to see inserted into the article, and include reliable sources using proper WP:CITING notation, and once you have it polished up in that sandbox post it here for our review and discussion. For talk pages, one way to handle the ref tags is to bracket them with nowkiki tags like this <nowiki><ref>example citation text</ref></nowiki>. In addition, check your math because 4mm per year for 100 years is 1.3 feet - not 11 as you said. NewsAndEventsGuy (talk) 15:58, 12 May 2013 (UTC)

There are a lot of quotes in the report in support of a statement that the IPCC observes "sea level rise is accelerating".

That's really all I would want to see added to the article

My math and method was wrong, Thank you for the correction. I should have used "linearly from 4 mm a year"

ie; doubling every decade, rather than "linearly at 4mm a year" and not continued the results out to 2100.

Continuing the line 1990 =1mm yr = 10 mm, 2000 = 2mm yr = 20 mm, 2010 =4mm a year = 40 mm = 70 mm total between 1990 and 2010

Continuing 80 mm projected between 2010 and 2020 = 150 mm total by 2020, 160 mm between 2020 and 2030 = 310 mm total by 2030

Continuing 320 mm between 2030 and 2040 = 630 mm total by 2040, 640 mm between 2040 and 2050 = 1.27 m total by 2050

Continuing 1280 mm between 2050 and 2060 = 2.55 m by 2060 and I should just stop there because...

Only in pure mathematics do straight lines or curves continue to infinity,

I doubt the acceleration continues to rise steadily indefinitely.

47 years is a time frame people can relate to better than 87 years.

Sometime before 2060 the warming ocean temperature causing sea level rise either levels out because we find a way to mediate it :::::: or the polar ice caps melt suddenly, in either case the rate of change changes; hopefully we choose to go with the course

where the perturbations do not become something from which it is "hard to recover" 12.187.95.227 (talk) 13:22, 13 May 2013 (UTC)

I see a tag on the top of this talk page reading: "Current sea level rise received a peer review by Wikipedia editors, which is now archived. It may contain ideas you can use to improve this article" but the link is broken. How does one access the peer review or fix the link? Drf5n (talk) 13:40, 8 June 2013 (UTC)

I removed the 'oldpeerreview|archive=1' tag from the top of this talk page, since there seems to be no such peer-review page in archives 1...9 --Drf5n (talk) 16:06, 19 June 2013 (UTC)

In digging deeper I found Wikipedia:Peer_review/Sea_level_rise/archive1 and Wikipedia:Peer_review/Sea_level_rise-old/archive1 Apparently an old name change broke the links. I'm not sure how to re-link them to the header tag stuff. --Drf5n (talk) 16:16, 19 June 2013 (UTC)

In an edit summary DocRuby (talk · contribs) said the basis of this revert was that "The cited RS article compares Miami's risk to only [sic] US cities, not any outside the US" That appears to be untrue.

My prior text, which Doc reverted, stated

"In terms of property damage, Miami has been listed as the world's city most vulnerable to sea level rise."

This is based on RS text, which I have since quoted in the ref itself. See this edit, in which the quote I added states

"The Organization for Economic Co-operation and Development lists Miami as the number-one most vulnerable city worldwide in terms of property damage, with more than $416 billion in assets at risk to storm-related flooding and sea-level rise."

I have no problem adding RS-based text to talk about other US cities, or other worldwide cities, or ways of measuring risk other than property damage. Nonetheless the RS says exactly what I wrote, and Doc's stated reason for reverting appears to be an error.

Doc, please self revert to restore my text, and if you like to supplement with other RS based text, that would be great. NewsAndEventsGuy (talk) 21:13, 21 June 2013 (UTC)

I agree, NAEG, and have made a change to bring the text there into line with the cited source. --Nigelj (talk) 12:30, 22 June 2013 (UTC)

ThanksNewsAndEventsGuy (talk) 00:16, 23 June 2013 (UTC)

I just got the message about this discussion. I missed that statement in the RS article, and your revision is closer to accurate than mine was. However, the RS article itself is poorly worded. The OECD said it's the world's city with the largest property value vulnerable to flooding and sealevel rise. That's not quite the same as the most vulnerable city; it's the most vulnerable property value. Or, still somewhat ambiguously but still more accurate to the OECD's statement, it's the city most vulnerable in terms of property value. Alternately, the OECD said it's the city most exposed to flooding and sealevel rise in terms of property damage. The point is that "vulnerable" is a measure of the probability of the event, not the size of the loss, or the combination of the two that is exposure. DocRuby (talk) 01:24, 5 July 2013 (UTC)

Related point - The section is titled "Cities" but mentions only Miami. Can someone add a link to information (in or out of Wikipedia) about the vulnerability of other major cities to flooding with sea level rise? E.g, what percent of city X would be flooded if sea levels rose by 50 cm? By 100 cm? That sort of thing. Thanks Wanderer57 (talk) 16:29, 27 August 2013 (UTC)

There are 100 major East Coast coastal cities with populations of 100,000 or greater whose infrastructure can't be saved from the leaked IPCC projections for sea level rise by 2100 with sea walls, levees, jetties, barrier islands, or other mediation. Rising sea levels pollute aquifers with salt, undermine the soil bearing capacity of coastal highrises, take out buried utilities such as water, sewer, gas, electric, and communications; destroy roads, and buildings, wharves, marinas, power plants (some nuclear), sewage treatment plants, and overcome the barriers for hazardous materials, landfills, bridges, tunnels, airports, seaports, and the inter coastal waterway. The same applies to the Gulf Coast only worse. 12.187.95.244 (talk) 14:12, 29 August 2013 (UTC)

Thank you. It would seem from this that rising sea levels can make some coastal areas "practically uninhabitable" even though the sea water level has not reached a point where the land is flooded. Is this a fair statement? Wanderer57 (talk) 03:16, 31 August 2013 (UTC)

I believe there was a recent mention in Nature as Miami being one of seven (?) cities in the world most vulnerable to sea-level rise. But a good point has been raised here, which should be considered further: is vulnerability to be measured by the cost of possible damage (losses) without taking any measures of mitigation (that is, how much value is at risk)? Or by the cost of mitigation? ~ J. Johnson (JJ) (talk) 23:37, 31 August 2013 (UTC)

Hi JJ. Long time. Those are good questions for those who produce what we eventually see as RSs. If we have RSs to cover both ways of looking at the question, that's what we should do. If we so far have RSs for only one way of looking at it then for now, that's what we should do. NewsAndEventsGuy (talk) 00:02, 1 September 2013 (UTC)

The cost of relocating a major city has been established by costs of repairing the damage from Katrina and Sandy. Allowing we begin now while some things can still be salvaged and simply relocated rather than demolished and then in many cases dragged off and entombed as hazardous wastes, and only then rebuilt, and the relocation is accomplished by 2100 we would be spending between 2 and 10 billion dollars a year per city for 100 cities for 87 years. One way to look at that is urban renewal and an economic stimulus that would provide construction jobs for many decades, indeed the better part of a century. Since many cities like New York have aging infrastructure which is about to fail anyway, a Master plan for relocation should be a part of every cities planning. Its likely the design planning by architects, engineers, urban planners, and politicians would take 25 years and the actual relocation construction another 50 - 60 years by which time its earlier portions would already be aging again. Lets say somewhere in the range of 100 trillion in round numbers with a likely inflation of costs in the range of a factor of ten over the next century. Most likely that would be too little too late as there are complications including what other countries do for their mediation.12.187.94.209 (talk) 09:05, 12 September 2013 (UTC)

Can anyone explain the archive structure? (Q1) I like having them subdivided by year, but why are some integers skipped, for example as I a type this comment, the index to archives includes this

"2012 / 1, 2, 4, 6, 7"

What happened to #3 and #5?

(Q2) When you open an archive, there is no "next" or "back" link to move forward and back in the archives. That is a useful feature. Could we easily turn it on? NewsAndEventsGuy (talk) 14:47, 5 November 2013 (UTC)

Could we post some graphs which show the 3 mm/year sea level rise? I'd like readers to be able to see at a glance the difference between the "current" sea level rise and the decades or centuries before it.

The graphs would also help to clarify what current means. Are we talking about the last 3 years, last decade, last couple of decades, or what?

I'm a math teacher, so I'd like to show this article to my class - but not yet: it would just confuse them at this point. --Uncle Ed (talk) 16:57, 10 November 2013 (UTC)

Hi. Thanks for the question. I'm currently working on an edit to clarify what time periods these rates apply to. In the mean time, you can find up-to-date data and graphs here: CU Sea Level Research Group, University of Colorado. You might also want to look at the recent Intergovernmental Panel on Climate Change Working Group I report (Summary for Policymakers, pp.8-9; Chapter 3, p.5). Enescot (talk) 07:00, 12 November 2013 (UTC)

Thanks, I'll take a look. --Uncle Ed (talk) 15:29, 15 November 2013 (UTC)

Several of the groups reporting Sea Level add in a Glacial Isostatic Adjustment which accounts for about 10% of the reported sea level rise, but is not actually based on rising water levels. http://sealevel.colorado.edu/content/what-glacial-isostatic-adjustment-gia-and-why-do-you-correct-it

Should a section be added to Wikipedia to explain this? Keelec (talk) 00:18, 22 December 2013 (UTC)

GIA should be added if not already in Wiki. However, GIA with respect to local sea level rise is a subset of the overall GIA topic. Atkinsonlp (talk) 01:21, 22 December 2013 (UTC)

There are good summaries of vulnerability of coastal cities by OECD and Core Logic. I'll get them in soon. Atkinsonlp (talk) 01:21, 22 December 2013 (UTC)

The lead section paragraph #5 needs an update in light of the release of the IPCC 2013 Fifth Assessment Report, Working Group 1 specifically Ch 13: Sea Level Change Grantbow (talk) 20:56, 17 March 2014 (UTC) Second that. Both the temperature and sea level graphs are now influencing State and Federal Flood Plane Insurance Maps, Category V coastal, which project 2 degrees C and two feet of sea level rise long before 2100 and are basing insurance rates of $2.10 per $100 on this report. 142.0.102.209 (talk) 20:52, 24 April 2014 (UTC)

http://www.dailykos.com/blog/rktect/142.0.102.47 (talk) 21:34, 8 May 2014 (UTC)

First line says:

"This article is about the current and future rise in sea level associated with global warming. For sea level changes in Earth's history, see Sea level."

Compare, Future sea level.

These three articles seem to cover more-or-less the same topic, or at least inextricably integrated topics:

Sea level

Current sea level rise, and

Future sea level

Among the three articles, there is a lot of good material, but being split into three articles, some will be overlooked. Could they be combined?

If kept separate, each separate article needs to be more tightly focused on its sub-topic, and to provide very clear, conspicuous, unavoidable cross-reference to the other articles at each appropriate opportunity. If separate, they could also be coordinated in part by more focused titles, which that can then reflected in more focused content. E.g.,

Change Future sea level title to Sea level rise - scientific projections (based on both pre-historic data and human measurements) This would be the master article, and contain sections stating the key points in the other two, and referring and linking to them for more detail.

Change Sea level title to Sea level - pre-historic (focus on fossil records etc. pre-dating human measurements); with similar referring and linking, and

Change Current sea level rise title to Sea level rise - measurements ; (focus on accelerating rise reflected in human measurements) and again, referring and linking to the others

— Preceding unsigned comment added by Ocdnctx (talk • contribs)

Send the other to AFD The original text of Future sea level appears to be a cut-and-pasted copy of an academic paper, is probably a WP:COPYVIO, and its scope is certainly redundant with Current sea level rise. It should be nominated at AFD. Not sure if POVFORk would apply but in any case FYI

• Current sea level rise was created in Jan 2002
• Future sea level was created June 23 2009 by UHCGgroup (talk · contribs), a single-purpose account with only one edit.

NewsAndEventsGuy (talk) 18:05, 1 June 2014 (UTC)

By the way, regarding the title of this article, I do think it is a little ambiguous, because people could either read it to mean

(A) the current RATE (today) of sea level rise, or

(B) the current EPISODE of sea level rise.

I have always understood this article to be about the current EPISODE, and so discussion of projections belongs here unless the result is such a long article that it becomes necessary to SPLIT it. If this article has not passed the too-long/must-split threshold, then I do not think projections should be addressed in a separate main article NewsAndEventsGuy (talk) 18:13, 1 June 2014 (UTC)

"water molecules expand as ocean water warms" Water molecules probably do not expand as ocean water warms. The distance between water molecules probably increases as water warms. — Preceding unsigned comment added by 2620:0:1000:3002:BE30:5BFF:FEDB:4C84 (talk) 00:05, 23 May 2014 (UTC)

Seawater has a coeficient of expansion which varies with its temperature and pressure. Metaphysical Engineering (talk) 13:37, 25 May 2014 (UTC)

Reworded per IPCC ref which simply says warmer water expands. Water volume increases and density decreases w/ increasing temperature ... so each molecule occupies more space due to increased molecular vibration. Vsmith (talk) 00:23, 26 May 2014 (UTC)

The maximum density of water occurs at 3.98 °C (39.16 °F).[12] Most known pure substances become more dense as they cool, however water has the anomalous property of becoming less dense when it is cooled to its solid form, ice. During cooling water becomes more dense until reaching 3.98 °C. Below this temperature, the open structure of ice is gradually formed in the low temperature water; the random orientations of the water molecules in the liquid are maintained by the thermal motion, and below 3.98 °C there is not enough thermal energy to maintain this randomness. As water is cooled there are two competing effects: 1) decreasing volume, and 2) increase overall volume of the liquid as the molecules begin to orient into the organized structure of ice. Between 3.98 °C and 0 °C, the second effect will cancel the first effect so the net effect is an increase of volume with decreasing temperature.[13] Water expands to occupy a 9% greater volume as ice, which accounts for the fact that ice floats on liquid water, as in icebergs.

That is from the Wiki on water.  — Preceding unsigned comment added by 50.103.46.170 (talk) 07:48, 7 November 2014 (UTC) 

I have been looking at the prediction for sea level rise based on ice melt. Most I have seen start with picture of ice mass at a given time in the past compared to percentage left of same ice mass today then draw straight line through both to produce future ice melt (liner model). This had to be revised upwards over the years but they still draw a straight line through new data point to predict future ice melt. Some talk about an exponential rise in sea level using sound empirical evidence but give no physics based model, leaving results up to interpretation. There are many variables to be considered but what is the underlying physics of ice melt, linear or exponential that variables should be applied to? In the following experiment, given a 1 meter square block of ice whose temperature has gone from -1c to the experiments starting point of 0c, apply a consent amount of energy on its upper surface only, ice melt allowed to runoff surface. Energy input is constant over time; surface area exposure of ice to energy is constant over time but the ice mass decreases over time as the ice melts down. Could you describe this with a linear or exponential equation? I can find lots of graph showing as energy is inputted into ice temp goes up until it gets to 0c then stays at 0c until melted completely. I can find equations that will tell me total energy to melt given amount of ice. I can not find anything that tells me at 25% of total time needed to melt a given amount ice you get 25% ice melt, at 75% of total time you get 75% ice melt (linear); OR at 25% of the total time needed to melt ice you get 10% ice melt, at 75% of total time you get 85% ice melt (exponential). — Preceding unsigned comment added by James B MacDonald (talk • contribs) 01:42, 19 July 2014 (UTC)

Try this post from RealClimate, also read the comments (search the page for "Hansen"), http://www.realclimate.org/index.php/archives/2013/11/sea-level-rise-what-the-experts-expect/ A overview about this broad topic can be found here https://forum.arctic-sea-ice.net/index.php?board=13.0 prokaryotes (talk) 09:01, 19 July 2014 (UTC)

A good blog entry on the topic NewsAndEventsGuy (talk) 12:33, 19 July 2014 (UTC)

Oh a great find, NAEG! prokaryotes (talk) 17:49, 19 July 2014 (UTC)

In the three years since Hansen projected that sea level may rise 5m by 2100 we have moved from just looking at West Antarctica to looking at the Totten glacier thinning in East Antarctica measured in the volume of Mount Everest melting every two years.142.0.102.20 (talk) 11:09, 24 March 2015 (UTC)

A simple formula that models the observed sea level rise by decade is available from Jim Titus of the EPA who has been writing papers on the topic for the EPA since the Reagan administration. The observations over the last quarter century indicate an exponential rate which is to say sea level rise is increasing at an increasing rate

1990 1 mm yr 1995 1 mm yr 2000 2 mm yr 2005 3 mm yr 2010 5 mm yr 2015 8 mm yr Its projected by the IPCC to be 4 feet by 2050 and six feet by 2100. After that it just goes off the chart to an eventual total rise of 60 meters 142.0.102.39 (talk) 02:55, 5 August 2014 (UTC)

You are not going to find a formula for this; the real world is not that simple. And I haven't seen any source that suggests we are at 8mm/yr right now (2015). It's simply not the case.MissPiggysBoyfriend (talk) 21:13, 10 June 2015 (UTC)

Mistake Paragraph Two: "Between 1870 and 2004, global average sea levels rose a total of 195 mm (7.7 in), and 1.46 mm (0.057 in) per year.[5]" should read "Between 1870 and 2004, global average sea levels rose a total of 195 mm (7.7 in), and 1.46 mm (0.057 in). [5]" Majermike (talk) 01:55, 29 August 2014 (UTC)

• Hanson and a host of others argue that it is non-linear. [1] Pkgx (talk) 16:16, 11 January 2016 (UTC)