Talk:Sea level rise/Archive 5

This is an archive of past discussions about Sea level rise. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

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Archive 3

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Archive 5

Archive 6

Any objection to adding a culture section? Following the recent death of visionary author Ursula LeGuin, I was reminded of Always Coming Home, which I am sure is one of many imaginings of how humans will learn to live with these sea rises. Carbon Caryatid (talk) 18:31, 31 January 2018 (UTC)

I would object. While sea level rise will likely have some cultural effects, at this point those are quite speculative. And "culture" sections tend to slide into collections of "pop culture" trivia. Sea level rise is an objective phenomenon; I have yet to see how "culture" would aid in understanding it. ♦ J. Johnson (JJ) (talk) 20:15, 2 June 2018 (UTC)

<<housekeeping note... This 2018 discussion "incorporates by reference" the one from 2015 so to begin I imported that one here. This way, it's all in one place. NewsAndEventsGuy (talk) 07:09, 24 August 2018 (UTC)<<

<<housekeeping note... Merge was also discussed at the other page. That thread was imported and hatted above. These two sections should be read together NewsAndEventsGuy (talk) 07:09, 24 August 2018 (UTC)<< The same proposal as in 2015, same arguments. Should future sea level be merged into this article in analogy with the difference sea level/global warming? I am willing to do the merging if we have enough support for a merge. This time it should be easier, because I've removed vast parts of the article future sea level, that were outdated/irrelevant. Femkemilene (talk) 12:53, 7 August 2018 (UTC)

• Support merge of Future sea level into Sea level rise. Not enough material to maintain a standalone article. — JFG ^talk 13:41, 7 August 2018 (UTC)
• Support per JFG, here is another yes vote. prokaryotes (talk) 14:08, 7 August 2018 (UTC)

Is it okay if I start merging in two weeks if there are no further comments? Including last times' support, I count 4 in favor, 0 against a merge. Femkemilene (talk) 14:25, 12 August 2018 (UTC)

Given there is no opposition, I'd say you can start merging immediately. — JFG ^talk 07:26, 13 August 2018 (UTC)

Amen, thank you for your service, hallelujah NewsAndEventsGuy (talk) 09:42, 13 August 2018 (UTC)

note I've shifted this down to its own section for visibility. Vsmith (talk) 13:32, 2 August 2018 (UTC)

Sea level rise is not globally uniform. In addition to the coefficient of warming things like subsidence, isostatic rebound, and ocean currents slowing are factors. The Gulf Stream's slowing is causing sea levels to rise in New England. Such deviations from the norm are worth a mention. More importantly temperatures are rising much faster in the arctic. Methane is being released much faster and in much greater quantities than are discussed here. The polar ice melt is increasing at an increasing at an increasing rate and the ice melt is ponding below the ice cap.24.93.139.28 (talk) 08:36, 2 August 2018 (UTC)

See Sea_level#Local_and_eustatic and WP:Be Bold. Go for it. NewsAndEventsGuy (talk) 15:35, 2 August 2018 (UTC)

Also, the changes in the distribution of ice and water over the Earth’s surface affects local gravitational field and the orientation and rate Earth’s rotation. These effects also cause relative sea level rise not to be globally uniform. For example, every foot of sea level rise resulting from melting of the West Antarctica ice sheet would result in over 1.3 feet of sea level rise along the east Atlantic and Gulf of Mexico coast of the United States and drop of 0.4 foot along the West Antarctic coast.

The two publications to see about this effect are:

Hay C, Lau H, Gomez N, Austermann J, Powell E, et al. 2017. Sea-level fingerprints in a region of complex Earth structure: The case of WAIS. Journal of Climate 30: 1881-1892. (open access) and

Mitrovica J, Gomez N, Morrow E, Hay C, Latychev K, Tamisiea M. 2011. On the robustness of predictions of sea level fingerprints. Geophysical Journal International 187: 729-742 Paul H. (talk) 02:43, 12 August 2018 (UTC)

Still the same problem as before. In the lead, instead of actually saying what the tidal gauges estimate as the current rate of sea level rise, it i gives several loose estimates on what someone believes it might be if co2 based catastrophic global warming predictions come true. How about we stick to actual measurements? Sea level rise is about 1.75 mm per year. — Preceding unsigned comment added by 24.107.12.180 (talk • contribs)

Given that the estimates are not based upon personal beliefs as is incorrectly stated above, but solid scientific research, I do not see this as a problem. In fact, it would be ethically negligent not note such research. Such changes would be like what the North Carolina state legislature did when they banned local and state agencies in House Bill 819 (S.L. 2012-201) from using in developing coastal policies well vetted and peer-reviewed scientific models indicating an accelerating rise in sea level instead of historical linear predictions. Paul H. (talk) 02:50, 12 August 2018 (UTC)

I do think we should include altimeter and gauge data measurements (or some study that combines the two) in the lede. As with the article about global warming, the scope of this article is the ~post 1850 changes in the earth system. Of course, projections are equally important and should not be removed. Femkemilene (talk) 11:49, 12 August 2018 (UTC) (P.S. don't forget to finish a contribution with 4 tildes, so that it is not anonymous).

Models are not measurements, and have no record of accuracy. If you want a seperate section for predictions then make one. The main of the adticle should be about science not speculation. The fact that the most basic info possible, the tidal gauges measurements, are supressed here is ridiculous. And no I don't see any problem with being anonymous, that was originally the whole point of wikipedia. Who you are doesn't matter only what you say. To recap: sea level rise is about 1.75 mm per year and did not show any acceleration during the 20th century. Nor would we have expected that a few tenths of a degree change in surface temps would make a notable difference. — Preceding unsigned comment added by 24.107.12.180 (talk • contribs)

Models are based on physical laws and as such have a lot of scientific merit. I do agree with you that the lede should have more information about measurements though. Your assertion that tidal gauge data do not show a acceleration in sea level rise is false, see for instance https://www.nature.com/articles/nature14093 and references therein. Femkemilene (talk) 13:11, 12 August 2018 (UTC)

Satellite altimetry also shows that sea level is accelerating since 1993. Go see: Nerem, R.S., Beckley, B.D., Fasullo, J.T., Hamlington, B.D., Masters, D. and Mitchum, G.T., 2018. Climate-change–driven accelerated sea-level rise detected in the altimeter era. Proceedings of the National Academy of Sciences, p.201717312. Paul H. (talk) 13:45, 12 August 2018 (UTC)

I've replaced an old estimate of satellite measurements with this one, as the old one had the miscalibrated Topex/Poseidon estimates. Thanks for pointing me towards the research. Femkemilene (talk) 14:11, 12 August 2018 (UTC)

• @Femkemilene: I prefer a 20th Century header for the Hansen paper, since otherwise the impression is that projections only existed after the year 2000. prokaryotes (talk) 16:41, 12 August 2018 (UTC)

The Hansen projection is mostly about the 21st century, so that's why I placed it there (tbf: I thought it was placed in 20th century because the projection was DONE in that century, instead of about that century). I think that it is indeed good to have the 20th century heading back, but then with projections specifically about that century... Femkemilene (talk) 16:51, 12 August 2018 (UTC)

P and F

This NASA chart represents the satellite bi-monthly data on sea level since 1993, in millimeters, adjusted for seasonal variation.^[1][2]

User:Trurle recently improved the article by tackling the mark-up. One of the changes was putting back a figure that User:prokaryotes had recently removed because of redundancy. I think it was a good idea to have that figure removed, because it took up a lot of space without giving that much information. What are your reasons for putting it back? Femkemilene (talk) 07:14, 14 August 2018 (UTC)

The figure (or to be exact, bar plot) has additional functionality compared to NASA standard graphical plot:
1) The user can read numerical values with 0.1mm precision directly from the bar plot, giving much more detailed feel of short-term changes
2) Seasonal effects are removed (NASA had that data in referenced FTP dataset, but did not publish it in graphical form)
3) The bar plot allows to aggregate data from different publishers with no latency (not used currently, but NASA/NOAA had problems keeping their of observation satellites continuously operational, therefore it can change in future) Trurle (talk) 08:31, 14 August 2018 (UTC)

I don't like the bar plot at all, it looks ugly, breaks the layout, is not updated more frequently, is not easy to read, actually doesn't offer any information from looking at it, other than presenting a curve trend. On the x-axis it counts up to 100, which i personally find just confusing. I want the NASA presentation. prokaryotes (talk) 09:01, 14 August 2018 (UTC)

I personally don't think that 0.1 precision is relevant to the reader. Less is more is also an important line for Wikipedia. To me it is also the same whether seasonal effects were removed (maybe a discussion of seasonal effects would be appropiate in the sea level article). Also: a bit of latency is not really a problem here I don't think.. I get a bit of a headache when I look at the figure, due to the stark blue/white contrast. Is that something you have as well? Femkemilene (talk) 10:57, 14 August 2018 (UTC)

Yes, all the tiny bars make it uncomfortable to watch. prokaryotes (talk) 12:03, 14 August 2018 (UTC)

@Trurle:

At first blush I don't see the value of the big manual chart that requires manual data input in the right format to update, comparerd to the conventional thumbnail that simply requires an image upload from the NASA RS from time to time. Your reasons for liking the bar chart better were ennumerated and my replies are

Re 1, any user who cares about .1mm precision is sufficiently sophisticated they will not rely on Wikipedia for more than a quickie overview and access to the underlying RSs and data so that level of precision is not terribly persuasive

Re 2, Just eyeballing these two options I don't see any noticeable difference with respect to "seasonal variation", so unless i'm missing something this reason seems moot

Re 3, To paraphrase Klingon Chancellor Gowron, you could be right, but not today! Since this is a functionality not presently needed, "just in case" isn't really a reason to choose one that comes with some readability/maintanence costs over another approach that doesn't.

NEW THOUGHT ... for those reasons involving the appearance and readability of either option, there are more formatting bells and whistles that could change the way either one is displayed. I have't made up my own mind yet. NewsAndEventsGuy (talk) 13:53, 14 August 2018 (UTC)

I vote for the NASA chart as it is, at least to me, it shows sufficient detail for Wikipedia, has a better appearance, and is more readable of the two charts. The bar chart appears rather clunky to me and more distracting. Paul H. (talk) 16:33, 14 August 2018 (UTC)

Thanks for your contributions. I will change the figures back to the more modest figure we had before. Femkemilene (talk) 10:00, 15 August 2018 (UTC)

Yes, the NASA original chart is clearer. I tried to improve the bar chart, but did not realize that the original chart was available. Better that way. — JFG ^talk 10:44, 16 August 2018 (UTC)

I plan to finish the physical part first as that is literature I'm most familiar with. One of the major changes to the effects and adaptation section I want to make, is removing the focus in the U.S. (I assume there is some policy for that, but can't find it via Google). User:Prokaryotes: awesome that you're adding stuff, but do keep in mind that the world is bigger than the US. I suspect we'll find Bangladesh mentioned twice as much as US in international sources about the effects of sea level rise. To what extent is it okay to add French, German, Dutch and Spanish sources if I can't find good English sources? I do suspect most of the adaptation literature is produced by governments. With those languages I will be able to cover a big part of the world. Femkemilene (talk) 20:47, 20 August 2018 (UTC)

Just wanted to add something about coastal erosion, was looking for a statement, "that for each inch in slrise, the coast retreats 100 meters" or something like that. The article previously only stated "may cause coastal erosion". For sources I would just recommend to google it. If it is in foreign language and there is no English source for it, it depends I guess, but would try to avoid foreign languages. prokaryotes (talk) 20:53, 20 August 2018 (UTC)

@F, Excellent! You might find assistance at Wikipedia:GLOBALIZE NewsAndEventsGuy (talk) 21:08, 20 August 2018 (UTC)

Cool. The Wikipedia:Verifiability page states that English sources are only preferred when they are of the same (or higher) quality as the non-English source. So I won't stick to the 'foreign' language of English for some details around adaptation I suspect, but have not had time to properly assess the literature. Femkemilene (talk) 09:43, 21 August 2018 (UTC)

At some point I'd like to nominate this article for the Good article category. I realize we still have some ground to cover. I read that the US "human dimension" units (feet/inches, is there a proper name for that?) should then be used as well as the customary/scientific units as meters. Couple of questions and remarks

Questions: How do you convert mm to inches? Is a statement as 0.01 inches insightful? Or is there some smaller unit? Are mm used in the US? In the NOAA page yearly sea level rise is stated in mm/year.

Remark: Reading a text with a lot of numbers is very boring. I've been trying to remove specific numbers whenever they were irrelevant (mostly when there were numbers of <10 years of sea level, or specific locations or a way to detailed comparison of two measuring methods). Considering we'll have to convert a lot of those numbers making the text even more boring, shall we keep with a less technical description of the topic? People can always read the technical reports if they want more details. If there are important numbers, we can always put them in a graph. Femkemilene (talk) 09:54, 23 August 2018 (UTC)

Thanks for doing the heavy lifting here.

(A) For background in answer to your question See Imperial units and United States customary units

(B) But most importantly for drafting this article see Manual of Style, section WP:MEASUREMENT

NewsAndEventsGuy (talk) 12:40, 23 August 2018 (UTC)

I've noticed NASA hasn't updated their 1993-present sat graph since April, more current graph available here via CSIRO http://www.cmar.csiro.au/sealevel/sl_hist_last_decades.html Wait a little or switch to the CSIRO flavor? Copyright: "Figures marked "CSIRO", are copyright CSIRO, but please feel free to use them, conditional on the figures not being altered, and their source being acknowledged, and with a link to this site where possible." prokaryotes (talk) 03:18, 24 August 2018 (UTC)

Patience :). I don't think that we need to have to most updated figure. Primary choice between figures should be which figure conveys information best and looks better with the rest of the page. I find both pictures ugly, but would go for NASA one. Femkemilene (talk) 07:20, 24 August 2018 (UTC)

Agree with Femkemilene. The CSIRO one would be preferable talking to nerds and geeks who will read all the text (and comprehend it first time through) but we have a much broader audience NewsAndEventsGuy (talk) 07:24, 24 August 2018 (UTC)

IPCC AR5 WG1 SPM includes "land water storage" in the list of main contributors. The range of its impact overlaps melting of Greenland ice sheet; overlaps melting of glaciers; and overlaps melting of antarctic ice sheet. Seems like it should be included. Careful readers will see that the low end of its range is lower than any of the others, so an argument could be made for "main" causes being the ones whose ranges start at a higher value. But with the overlap in the ranges I think that's a dubious peg on which to hang ones hat. Land water storage should be included, at least briefly. But wait, I take it back. The above was based on section B. Later in Section D at page 17, the SPM explicitly says thermal expansion and melting are the larges contributors. Rather than delete my comment I left it in case I forget and make this mistake again. NewsAndEventsGuy (talk) 12:20, 24 August 2018 (UTC)

Just noting a primary RS on a nuance for followup later Under-estimated wave contribution to coastal sea-level rise NewsAndEventsGuy (talk) 12:35, 24 August 2018 (UTC)

What the paper is saying is that the amount of change in relative sea level along any stretch of shoreline is not going to match the amount of change in global (eustatic) sea level for the same period, *in part*, because of either positive or negative changes in local relative sea level reflecting changing wave regimes. Therefore, if a person wants to predict the change in relative sea level for a stretch of shoreline for a given amount of change in global (eustatic) sea level, local changes in wave regime resulting form sea level rise need to be factored into how this relative sea level is calculated. Paul H. (talk) 13:29, 24 August 2018 (UTC)

Thanks, and gesundheit NewsAndEventsGuy (talk) 13:32, 24 August 2018 (UTC)

I think we should mention, "The Antarctic Peninsula is among the most rapidly warming areas of the planet, with temperatures having increased by almost 3C over the last 50 years." ... Central West Antarctica among the most rapidly warming regions on Earth prokaryotes (talk) 15:23, 24 August 2018 (UTC)

I get sooooooo tired of repeating the same objections. You know why this matters. I know why this matters. We eds who follow this know why this matters. BUT just like a bunch of prior proposals from you this is original research because appear to be connecting the dots. What we need is RSs that connect the dots and a proposal how the article can be improved without relying on our own implied beliefs about why things are important. Please understand, I'm not opposed to saying something about WAIS warming it genuinely makes sense in the context of our article and it is the RSs speaking not us and not by way of implied anything. NewsAndEventsGuy (talk) 15:50, 24 August 2018 (UTC)

If it goes anywhere, probably the section Sea_level_rise#Antarctica. I'm opposed to just sticking in a random factoid about gee its getting hot there fast. But if there are RSs that talk about rapid warming and potential for ice sheet destablization, etc. sure, suggest something. NewsAndEventsGuy (talk) 16:01, 24 August 2018 (UTC)

How is this OR, (quote from the study I cited above....) "In contrast to previous studies, we report statistically significant warming during austral summer, particularly in December–January, the peak of the melting season. A continued rise in summer temperatures could lead to more frequent and extensive episodes of surface melting of the West Antarctic Ice Sheet." prokaryotes (talk) 16:25, 24 August 2018 (UTC)

I am the top editor of this article, but somehow when I try to be constructive on talk page during times when others are active, my input, at least by you is often misunderstood. you do not seem to check the sources I provide. So I will try to be more on point in the future, but you crying OR is just not helpful. Judge me by my article edits, thanks :) prokaryotes (talk) 16:33, 24 August 2018 (UTC)

I can't read your mind, P. What you wrote in the opening post was OR, "Gee its getting hot there fast" (assuming everyone will know what this has to do with SLR). You only made a complete thought in the reply. If you just assume I'll scream OR when you make these assumptions both of our days on wiki will be brighter. Paying attention to this will help ensure these assumptions don't make it into text. NewsAndEventsGuy (talk) 20:03, 24 August 2018 (UTC)

The introduction now puts both the IPCC and the NOAA numbers next to each other. This implies they two organisations are talking about the same thing, but vastly disagree. This apparent disagreement is amplified by the sentence that modelling sea level rise is difficult. As you might be aware of, the IPCC uses a 66% confidence interval, and the NOAA uses different probabilistic projections in the literature to determine some extreme scenario. The sources they use give an approximate 1% chance for these extreme scenarios. Not entirely sure how to write properly, but this might be interpreted wrong by many readers. Femkemilene (talk) 16:47, 24 August 2018 (UTC)

Speaking as the turd who wrote that stuff..... excellent criticism!!! In the big picture, the really important thing I was trying to convey is the consistent increase in projections (which is true). Start with AR1 and step through all the estimates. Each time it goes up. In the RSs (and better blogs) is the story of what was known, what was assumed, and what was left out as a "known unknown". As the pieces have come in, the projections keep going up... in the IPCC assessment reports themselves. Also, Google and GoogleScholar search for _IPCC "sea level" underestimate OR conservative_ yields many RSs telling versions of this trend in our understanding. I am not concerend with shoving really high numbers into the lead, nor numbers of ultra low probability. What I am very concerned with is that this paragraph explain the basic trend line reported in these RSs, as we learn more projections go up. If we leave off with the AR5 numbers, we can observe that many papers say its possible to have a ton more but odds of it happening are way low. Of course the body will need to go into that in more details. Does any of this paragraph make sense, or does it sound like hand waving? NewsAndEventsGuy (talk) 16:57, 24 August 2018 (UTC)

Of course others may edit in the meantime, but I'll ponder RSs and fixes during my morning session tomorrow.NewsAndEventsGuy (talk) 17:10, 24 August 2018 (UTC)

Makes sense, agree with conveying the increased projections (maybe a bit more subtle??) and agree with mentioning the extreme case (NOAA does a good job in conveying why these numbers are relevant). You are good with wording things simply, so I'll wait for your morning session :). Femkemilene (talk) 17:15, 24 August 2018 (UTC)

For a start, see the discussion at IPCC AR5 WG1 Tech Summary pages 98-99 (as printed on the page). Their projections are (stated range) but then they say (paraphrased) "plus maybe more due to ice sheet instability". Any statement of the range that omits the "plus maybe more" is an incomplete statement of their projection. Its a bit frustrating (as many PRIMARY sources can be) because they seem to say (A) there's no consensus about the 'maybe more' factors and then (B) they seem to quantify a range and likelihood despite the supposed lack of consensus. If I weren't hungry for lunch and hot from labor maybe I would have perceived the nuance. But that's what hunting secondary RSs is for. NewsAndEventsGuy (talk) 17:21, 24 August 2018 (UTC)

The sentence with 'physically plausible' is defintely an improvement. Why the " "? Maybe we could say up to 2.0-2.7 meters? Femkemilene (talk) 07:54, 25 August 2018 (UTC)

Direct quote. As this section is polished (and if it remains) maybe that part will get inline attribution so fact its a direct quote is more obvious. Stay tuned. May take longer than thought, there are loads of RSs to ponder before rushing an attempt at patching, but starting work today. NewsAndEventsGuy (talk) 11:03, 25 August 2018 (UTC)

In this edit JFG removed text asserting a certain RS asserted a rise began about 150 years ago. My preliminary comments are - (A) since there is no SECONDARY source coverage of the PRIMARY source cited, use of this PRIMARY source is dubious. (B) So far I have no opinion whether the reverted text was useful.
Reason for my comment is that I disagree with JFG's reason for the revert. The edit sum reads "Nothing in cited source asserts a new trend since 1850: sea level has remained mostly stable "from 6.7 ka to recent time". What the devil do geologists mean when they use the phrase "recent time"? That's a rhetorical question. We all know that to understand geo-nerds you need a hint of the order of magnitude they're thinking about in any given context. Here, 1850 is indeed "recent" because the abstract does allude to a new trend starting in about 1850. Here is the cited source. The source "significance" paragraph (before the abstract) says

Of particular note is that during the ∼6,000 y up to the start of the recent rise ∼100−150 y ago, there is no evidence for global oscillations in sea level on time scales exceeding ∼200 y duration or 15−20 cm amplitude. (bold added)

and the abstract says

....progressive decrease in the rate of rise from 8.2 ka to ∼2.5 ka BP, after which ocean volumes remained nearly constant until the renewed sea-level rise at 100–150 y ago,.... (bold added)

Since they note the "recent rise" that started in 1850, they have told us how to understand the bit quoted in the edit summary. The RS does indeed say a new trend started about 150 years ago, so the text should be restored if it makes a better article. I haven't focused on this seciton yet and so have not yet formed an opinion. NewsAndEventsGuy (talk) 12:21, 25 August 2018 (UTC)

The issue is indeed with orders of magnitude. The essence of the cited study (and the graph we use to illustrate it) is to show that "recent" SLR over the last few thousand years is immensely slower than the previous rise. We should not conflate this with "very recent" data that shows an increase of the rate of rise from maybe 1 mm/year to 3 mm/year. It does look like a big increase, but in the grand scheme of things, it remains very small. At this rate, mean sea level would only rise 30 cm in a century, and that contradicts some of the predictions for several meters of SLR by 2100. This discrepancy needs to be explained, to avoid leaving our readers puzzled. — JFG ^talk 12:40, 25 August 2018 (UTC)

I hear you, but for all of us just a reminder that we need to be ever on guard against characterizing anything as "small". Or big, for that matter. Such evaluations is the job of RSs. But on the general point you raise. I think I agree. I think you're saying, more or less, is that readers need to understand that the RSs say we are on the earlier (and flatter) parts of a projected exponential curve. Correct me if that's quite it, please NewsAndEventsGuy (talk) 13:13, 25 August 2018 (UTC)

I think this source is 90% secondary source, 10% primary. Most of the points for which I've used the source, I've taken from the part of the paper establishing known facts (when Last Glacial maximum started, the existence of meltwater pulses, the ~125 meter rise). The new thing of this paper is that they have been able to more exactly date the 2500 years ago plateau/8200 slowdown in sea level rise. I think if we want a secondary source, we should only be looking for these two statements. Because this paper is just a extension of old research and therefore not much controversially new, I'm not going to make it a priority to look for secondary sources here.

JFG: I've tried to explain the differences in the 20th century and the 21st century in the first paragraph of contributions. Basically, we have seen sea rise only due to thermal heating and glacial melt in the 20th century, not really the big ice sheets. Evidence from measurements, modelling and paleodata suggests that ice sheet melt will increase. How could that be made more clear in the text? The IPCC AR5 sea level chapter has this on the second page: "It is very likely that the rate of global mean sea level rise during the 21st century will exceed the rate observed during 1971–2010 for all Representative Concentration Pathway (RCP) scenarios due to increases in ocean warming and loss of mass from glaciers and ice sheets". Do you think we should paraphrase that in the first paragraph of the lede (I would live out the RCP scenarios to keep it super simple). Femkemilene (talk) 15:13, 25 August 2018 (UTC)

• The lede now has two statements that are use feet as the primary (and only) measure. According to the page NewsAndEventsGuy sent me, in articles that are not primarily about the US/scientific in nature SI units should be used as the primary unit. Especially since the IPCC uses meters in their projections, we should do that.

Related, False impression of accuracy. 1 m is converted to 3 f 3 inches. The latter is way more precise than the former and I'm not sure that such precision can be backed up.

• I found the source page for the claim that sea level rise is expected to accelerate in 21st century. The exact claim is: compared to 1971-2010, so more than 2.0 mm/year.
• Field work: it is now implied that fieldwork is the only thing that led to improved ice sheet modelling. I think this is quite far from the truth. For instance, this paper https://www.nature.com/articles/s41467-018-05003-z shows that major improvements have been made after some bloke did some theoretical mathematical modelling in ice-sheet instability. This led modelling groups to stop assuming the shallow ice approximation and led to ice sheets reacting to climate change over centuries instead of millenia. Furthermore, I would (unsourced) venture that satellites are more important than field work for collecting measurements.

I will leave it to you to change it for now :). Might help later, but my partner has woken up. Femkemilene (talk) 07:52, 25 August 2018 (UTC)

Thanks for all your work. Reading the lede from a non-expert standpoint, it gives the impression of jumping directly into explanations of sea level rise related to the recent warming of oceans, although we learn later in the article that sea level has risen a lot faster in the past due to post-glacial rebound, and that it has been mostly stable over the last couple of millennia. The introduction sentences would benefit from being rephrased as a more general overview, first describing measurements and trends, then historical and current causes, and finally future projections depending on various hypotheses. — JFG ^talk 09:10, 25 August 2018 (UTC)

@JFG, That hints at the ephemeral question What is the scope of this article? I thought in the merge discussion we'd agreed to treat this topic somewhat analogous to climate change and global warming, where one page covers the internal variation (such as isostatic rebound after regular glacial periods) and the other page covered the current episode driven mostly by humans. The lead can be improved to make whatever we decide clear, for sure. I'd still like to stick with the latter, and put things like internal variation and regional differences mostly in sea level NewsAndEventsGuy (talk) 11:08, 25 August 2018 (UTC)

@Femkemilene,

(A) RE Measurements and the related issue of precision when converting, in the bigger picture, I'd prefer to stay as far from numbers and units as possible, since that makes our science articles harder for the lay public to engage. But I do agree our units should be standardized and agree we should stick to metric. I never both converting units in preexisting text or from units used in RSs until text itself is stabilized. Anyone else can leap on that anytime. In the related issue where wikicode <nowiki>around 1 to 4 metres (3 ft 3 in to 13 ft 1 in) <nowiki> produces text reading "around 1 to 4 metres (3 ft 3 in to 13 ft 1 in)", whoever first typed that was careful to use our standard conversion template. In general, that's a good habit if we want to include alternative units of measure. In this instance, the word 'around' seems a good reason to excercise editorial discretion and dispense with the template, and just type "around 1-4 m (3-13 ft)".

(B) Re the source page and quote for acceleration, we have a great deal of text about that in the body of the article and in the lead its clutter. KISS (Keep it super simple). Remember that no citations are required in the lead at all, except for stuff likely to be challenged. This is a good example of something some arguers will challenge. But we don't need to repeat the body's nerd-speak here in the lead. SO page=good. Quote=clutter.

(C) Why projections changed. Good comments I'll mull on changes as I turn to reading and processing RS today and tomorrow.NewsAndEventsGuy (talk) 11:37, 25 August 2018 (UTC)

@JFG: I agree with NAEG. I've added some things about past sea level rise now, in line with the IPCC report to make clear its relevance to current sea level rise. I would like not to start the discussion about the scope again. The IPCC has a lot of attention to regional differences in sea level rise, so that should be included. Regional differences that are not set to change and internal variations should indeed be in the sea level article.

(A) Agree

(B) Perfect :)

(C) I'm not entirely certain I'm satisfied with this paragraph as it is.. The overall gist I get from it is that we downplay the current knowledge of sea level change ('Projecting future sea level has always been challenging, due to insufficient understanding many aspects of the climate system.' is quite negative). I'm not entirely sure whether such a negative statement is supported by our sources. Reading the IPCC AR5 WGI 13.8 (which is outdated here, so our understanding is further improved since): 'Understanding of the components that contribute to total sea level rise has improved significantly. For the 20th century, the range from an ensemble of such process-based models encompasses the observed rise when allowances are made for lack of inclusion of volcanic forcing in AOGCM control simulations, natural climate variability, and a possible small long-term ice-sheet contribution.' I do feel this is at odd with 'insufficient understanding many aspects'. Let me think about this a bit more.. Femkemilene (talk) 07:27, 26 August 2018 (UTC)

(C) Me neither. Though really knowing what I'm talking about will still take more RS research time. I haven't reviewed new edits since my last session yet. If you already found the right touch, great. If you try before I do, great. But I do intend to make a review when I've done the legwork necessary to think I have a reason to opine. Its a busy time of year. NewsAndEventsGuy (talk) 11:57, 26 August 2018 (UTC)

(e/c) Earlier today Prokaryotes added a new section titled "definition". I found this rather incomprehensible after a quick reading and the wikilink to the broad topic of geomorphology is an EGG. The new text I removed read

-- Definition --

-- See also Glacial isostatic adjustment --

The sea-level equation factors the deformations of the solid Earth, gravitational and rotational effects on sea level. These factors are sensitive to the Earth’s mechanical properties and to the melting chronology of land based ice masses.

The sea level can be expressed as

S = N − U

With S is the rate of change in sea level relative to the solid Earth, N is the geocentric rate of sea-level change, and U is the vertical rate of displacement of the solid Earth. (The ref was called by name so for convenience here on talk, this is the url)

Let's see if we can craft some comprehensible 5th grade level English here on talk before restoring this section. See WP:NOTJARGON paragraphs 7 and 8. NewsAndEventsGuy (talk) 22:57, 28 August 2018 (UTC)

Guy, what about we move that section to Measurements, under Sea level equation? Changing the wording of a formula is not really very feasible. prokaryotes (talk) 22:53, 28 August 2018 (UTC)

I'm opposed to using a formula at all. Instead, write a paragraph any 5th grader can understand that explains the formula. NewsAndEventsGuy (talk) 22:59, 28 August 2018 (UTC)

Done. prokaryotes (talk) 23:18, 28 August 2018 (UTC)

Regarding a recent change to a citation in the "Satellites" section: The original citation was bad, but removing mention of AVISO and Climate Reanalyzer (here here), leaving the text attributed solely and directly to Dr. Hansen, is wrong. The actual source is a blog (https://robertscribbler.com) of unknown authorship, which says: "Sea level rise analysis and update based on information provided by AVISO, Climate Reanalyzer, and the work of Dr. James Hansen." Where specific claims are made the original source should always be cited. This blog might be informed, might be accurate, but is not a reliable source, and citing it misattributes the source of the supposed fact. Remediation requires findng the original, authoritative source; it can probably be found in one of the IPCC reports. ♦ J. Johnson (JJ) (talk) 17:47, 23 August 2018 (UTC)

As an aside, this particular blog knows its stuff but I agree its not RS. I disagree with J Johnson's urging us to find and rely on the PRIMARY original source. Far better to find unquestionably reliable mainstream SECONDARY sources that talk about the primary source and use those. Actually, I usually edit on the basis of science journalism for lay people, and when I add refs I add the SECONDARY source I'm mostly going with but add a link to the PRIMARY source the secondary source is tellign the public about. See WP:NOTJOURNAL and WP:PRIMARY. NewsAndEventsGuy (talk) 18:01, 23 August 2018 (UTC)

• Comment A related study Mass balance of the Antarctic Ice Sheet from 1992 to 2017 "surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres" This study is cited two times in the Antarctic section, but does not states the increases in mm or factor. WAPO on this study, "Csatho noted that comparing the first and last five-year periods in the record reveals an even steeper acceleration. “Actually, if you compare 1997-2002 to 2012-2017, the increase is even larger, a factor of more than 5!!” ... "For the total period from 1992 through the present, the ice sheet has lost nearly 3 trillion tons of ice, equating to just less than 8 millimeters of sea-level rise. Forty percent of that loss has occurred in the past five years."prokaryotes (talk) 18:36, 23 August 2018 (UTC)

It seems like it would be better to at look at the interactive discussion of Hansen et al. (2016) instead of the blog interpreting that paper. By the way, I looked at Google Scholar and it indicated 233 cites for Hansen et al. (2016) as of today. The original paper is:

Hansen, J., Sato, M., Hearty, P., Ruedy, R., Kelley, M., Masson-Delmotte, V., Russell, G., Tselioudis, G., Cao, J., Rignot, E. and Velicogna, I., 2016. Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 C global warming could be dangerous. Atmospheric Chemistry and Physics, 16(6), pp.3761-3812. Paul H. (talk) 20:46, 23 August 2018 (UTC)

Nice find! Though I reckon any significant statements are likely also found in the IPCC ARs. As to why we should cite the cite the original and authoritative sources of data (distinguished from novel interpretations): I hope to have a comment ready tomorrow. ♦ J. Johnson (JJ) (talk) 23:38, 23 August 2018 (UTC)

(A) Much of the 2016 Hansen paper is likely not covered by the 2013/2014 AR5 statements (and remember the latter are based on even older data).

(B) Look forward to your comment, and hope it is consistent with WP:PRIMARY and subsequent sections on WP:SECONDARY and WP:TERTIARY. NewsAndEventsGuy (talk) 23:56, 23 August 2018 (UTC)

A lot discussed here at the same time I feel. A few additional comments:

• The original question was about the sources of the very recent sea level rise. I think we shouldn't mention trends that are smaller than 10 years to a) not report trends that might be internal variability b) make prose readable without having too many numbers c) keep it easy for this article to remain up to date.
• The Hansen paper is already mentioned in the text under the projections section. The discussion paper (paper before peer review) is cited. At the very least, we should check whether there comments are still true in the peer-reviewed paper
• High citation score does not mean it is reliable/consensus view, but only that many people were interested, maybe because they did NOT agree with methodology.
• In conclusion: I'd say get rid of very recent sea level rise altogether, check whether Hansen paper remained the same after peer review, give paper less space and check whether secondary sources agree with Hansen paper. Femkemilene (talk) 07:31, 24 August 2018 (UTC)

I agree with Femkemilene, though I'd quibble about we shouldn't mention trends that are smaller than 10 years to a) not report trends that might be internal variability because we should report what we find in RSs and if they think smaller trends are important we should cover them too. In that case, hopefully we will be able to do that without bogging down with numbers and stats as we explain the climate system, ocean dynamics, and what it all means. Its all in the SECONDARY reliable sources baby. Yeah!! Where such small trends are reported as internal variability if we mention them at all, it might be better to do it at Sea level NewsAndEventsGuy (talk) 07:46, 24 August 2018 (UTC)

I agree that "...high citation score does not mean it is reliable/consensus view,..." I take it to mean that fellow researchers consider the paper to be significant enough to be worth their time and effort to either use or discuss it regardless he or she either agrees or disagrees with it. In either case, there is something about the paper, either positive or negative, that the commentators feel strongly that their collegues should either know about or corrected. By the way, Femkemilene, keep up the excellent work. Paul H. (talk) 13:42, 24 August 2018 (UTC)

• The essential element of WP:PRIMARY is that primary sources may be used, "but only with care". Specifically, a primary source may be used "to make straightforward, descriptive statements of facts that can be verified by any educated person with access to the primary source but without further, specialized knowledge."

A key concern is the evaluation or interpretation of material from a primary source. (This actually applies to all sources.) In the case at hand the content supported was that the rate of sea-level rise "in 2010-2018 was 4.6 millimetres per year". This is, clearly and definitely, a straightforward, descriptive statement of an alleged fact, that can be verified given access to the correct, and original, source. Which is now attributed to Dr. Hansen, but without any identification of where. Note that from this blog actually cited we have only a statement by this anonymous "robertscribbler.com" which is ambiguously (amtriguously?) attributed to Hansen, "Aviso", and "Climate Reanalyzer", with absolutely no information on any of those sources. Removing (as here) any mention of these latter two alleged sources makes it harder to find the original source of this alleged statement. It is also an inherent interpretation (perhaps even OR?) that Hansen is the actual source. As it currently stands, the material can attributed only to "robertscribbler.com", who does not qualify as a reliable source.

There is another aspect of primary sources that WP:PRIMARY does not get into: that such sources are generally present new, even novel, data, theories, and interpretations, which are not necessarily accepted as "true". Part of the role of secondary sources is to assess whether such data, etc., can be accepted as true, and it is extremely valuable, in addition to citing the original source, to cite a secondary source (as NAEG describes above) to support the implicit assertion that the primary source is valid. In this regard it should be noted that the IPCC summaries are a secondary source of the highest quality, whereas self-published blogs are largely valueless, and "generally unacceptable" (per WP:USERG; see also WP:BLOGS). ♦ J. Johnson (JJ) (talk) 20:08, 25 August 2018 (UTC)

I've removed this part, it is really too vague, had too many issues. Generally year to year trends are not that reliable, due to the high amount of inter annual variability of discharge rates. prokaryotes (talk) 02:02, 29 August 2018 (UTC)

I propose we keep numbers in the contribution section to a minimum and instead have an informative box-plot with the following information:

• rates of important contributors up till now
• rates of RCP2.6
• rates of RCP8.5

There are a few reasons for this

• Too many numbers make the text very boring to read.
• Numbers don't give intuitive information to readers
• Numbers become outdated fast, leading to difficulty in interpretation
• Without a figure, it's difficult to compare numbers spread across a text
• Different sources give numbers in different forms. I don't have a clue what a gigaton is, expressed in mm per year and would like to remove all mentions of this.

Specifically for the contributions section I'd like to propose there to be a rough indication of the magnitude of all contributions in the first paragraph (percentages are good, thanks User:Prokaryotes, but no/barely any mention in the subsection. This information would instead be captured in a graph based on the IPCC values. If you agree, could you help doing this? I really shouldn't be spending my work hours on Wikipedia now. I'll put the code for the figure up on Github, so that with the September 2019 IPCC report, it can be updated easily. Femkemilene (talk) 08:50, 29 August 2018 (UTC)

Yes, we should just keep numbers to the section lead, or to a subsection called Estimates (Contribution -> Estimates)?

There could be a infobox with figures, could serve well too. So this infobox would have about a dozen of figures? It could look similar to this table here. :Notice however, some studies exclude thermal expansion, or only look at Greenland's ice caps and glaciers, or only the main ice sheet. Then we have glaciers and the attribution from land stored water, which are generally sparsely covered, so different studies offer different results, but usually agree with the trend (only few outliers).

Personally, I find the mm values much easier to imagine instead of xx gigatons figures (so this table/infobox, should state gt's/mm) - how do you imagine a specific gigaton in sea level equivalent? Yes it offers some brief magnitude estimate too, but imho much easier to think of the actual amount the sea is raised. We should also note below the table that these figures usually do not account for thermal expansion, and that it varies locally.

The table should not be constraint to just IPCC values, ie. also important contribution rates up till now. prokaryotes (talk) 11:04, 29 August 2018 (UTC)

The formulation of "according to at least one study in 2017' is problematic. Is it held true or not? What do secondary sources say? Either you trust a study (because you use the paper as a secondary source or other secondary sources have used this study) and you leave out the 'according to', or you don't trust it and don't include it in Wikipedia. Femkemilene (talk) 10:00, 29 August 2018 (UTC)

Some eds seem to string studies together like this as if we were making popcorn garlands, and I agree the tendency is problematic. However, sometimes we can use inline attribution. Whether adding a given study to the popcorn chain in this fashion makes a better article is another question. NewsAndEventsGuy (talk) 10:58, 29 August 2018 (UTC)

It isn't always the question if a result/conclusion is true or not, but how reliable it is. Since that study concluded that ice cap and glacier melt at Greenland are irreversible, it should be pointed out that this result comes from a single study. Because, it was not immediately clear if other studies are in agreement, hence the emphasis there. I slightly edited the part. prokaryotes (talk) 11:12, 29 August 2018 (UTC)

If it isn't clear to you that other studies are in agreement, could you please not add it yet, but first try to figure out if other studies agree? Femkemilene (talk) 11:25, 29 August 2018 (UTC)

The idea that Greenland has passed a "tipping point" is not controversial, though I don't like the TP language myself William M. Connolley (talk) 11:29, 29 August 2018 (UTC)

There are many examples where we cover results, even if controversial (And to my knowledge this study is not considered controversial), as long peer-reviewed and covered in secondary sources - both the case here. This helps to inform the reader about the topic at hand (what are the extremes, what are the conservative estimates, and so on). If there is a equal study we would then continue later along the lines, eg. "However, it was later shown that only about 50% of glaciers and ice caps crossed a irreversible tipping point." prokaryotes (talk) 11:37, 29 August 2018 (UTC)

I've been a bit grumpy this morning, sorry. I've not read the source myself, so this was mainly expressing that we should not have articles that are a string of 'Study A says X, study B says Y', without looking at overarching research. If you did, the study is interchangeable and a note as reference suffices. Only if there is a controversy covered in secondary sources it is important to note in our text who said what, but as you say this isn't controversial, that shouldn't be the case and the reference can be done in the normal manner, without referring to 'the study', 'the researchers' or 'the year' in our main text.

TP language? Femkemilene (talk) 12:20, 29 August 2018 (UTC)

For now, I removed Prokaryotes text "and this trend could further destabilize the main ice-sheet" because after reading both references (the primary source and the HuffPo column) I can not find text that links the trend now underway on the "peripheral glaciers and ice caps" with destabilization of the main ice sheet. Fun (to me) side note, I posted some speculative OR many years ago in online forum(s) wondering if we would see faster runoff when the firn fills and refreezes. Now when I do some more OR, I agree if the peripheral glaciers and ice caps go away that might - in my opinion - contribute to destabilization of the main ice sheet. I can certainly understand why you might think that way too P. HOWEVER, maybe I missed the text in these RSs that connects these dots. Below please quote the specific sentence or two you think makes this connection from these sources? NewsAndEventsGuy (talk) 11:41, 29 August 2018 (UTC)

The trend here refers to the warming/thawing - it is stated as "and will continue to melt, and this trend could further destabilize the main ice-sheet" (the trend is, it is warming, and it is subsequently thawing - it is a trend), for now primarily affecting Greenland's glaciers and ice caps, but this same warming induced melt trend also is already affecting the main ice sheet. From the HuffPost article (which cites the studies authors), "The ice sheet is larger and more climatologically isolated than the coastal ice bodies and therefore more stable, but researchers have already observed similar changes to certain parts of the ice sheet’s firn layer, said Howat. These changes are part of “an important process in increasing the rate at which the ice sheet responds to warming, even if it is much slower than the little glaciers at the periphery,” he said." -- Can this be worded differently to define the meaning of the trend more precise, yes certainly. We could write, similar, the rate of melting is also increasing for Greenland's main ice sheet ....prokaryotes (talk) 11:59, 29 August 2018 (UTC)

In my view, you're stretching to shoehorn in more OMG ITS REALLY BAD implications while pretty much skipping over the really interesting stuff here. How about starting with IPCC's projecitons and their statement that they really don't know enough about ice sheet dynamics, and then telling a few stories about work being done to learn more about ice sheet dynamics? If we took that approach, then we could tell the real meat of these RS ---- what firn is... these researchers observation that firn can be a sponge until its turned to ice.... after its ice instead of firn nonlinear runoff happens..... This is an example of filling in the gaps of knowledge so the next IPCC projections can be mire informed than the last ones. We don't make a very interesting or useful article dropping discrete this/that and shoehorning in speculative implications for worst case scenarios. Instead we should weave an interconnected story. NewsAndEventsGuy (talk) 12:15, 29 August 2018 (UTC)

Another quote from the HP article, "The same processes that have caused the accelerated melting of Greenland’s coastal ice bodies could also influence the island’s massive ice sheet — with devastating results, Noël said.". Notice that we probably should write about the underlying mechanism related to the accumulation of fern, and the refreezing regime. prokaryotes (talk) 12:13, 29 August 2018 (UTC)

Telling the firn story is a good idea, but let's not dilute the presentation with a rhetorical reference to the all encompassing "same processes might melt the main ice sheet too" as we tell it. We have a whole section talking about Greenland. If we include this study we should only talk about the firn and maybe this teams belief that the peripheral glaciers and ice caps are doomed. I don't htink they said how long they have, did they? NewsAndEventsGuy (talk) 12:22, 29 August 2018 (UTC) PS Elsewhere, or in the future, I suppose someone will have something to say about how the loss of the peripheral ice might alter albedo, regional weather changes, etc and how those changes will impact the main ice. But these sources don't say those things. NewsAndEventsGuy (talk) 12:25, 29 August 2018 (UTC)

Does anyone object if I combine the archives for the various years into just one page? For example, I already combined the multiple archive pages for 2006 into just one. Most of them had just one or two short threads. This effort is intended as a prelude to tuning up the auto archive feature so it mimics the way we do it at Talk:Global warming, except we can still archive here at 180 days, compared to just 21 over there. NewsAndEventsGuy (talk) 00:32, 20 December 2016 (UTC)

No objection, would be good if we can automatically archive here as well. Femkemilene (talk) 14:27, 12 August 2018 (UTC)

This is fairly gnomish, I'll resume work on it slowly NewsAndEventsGuy (talk) 12:48, 23 August 2018 (UTC)

Work in progress NewsAndEventsGuy (talk) 16:40, 23 August 2018 (UTC)

 Done. I have finished merging yearly archives to a sequence of Archive 1 to Archive 6, up to 2014. The bot is reconfigured to take over from there, starting with Archive 7. Year archives are redirected to the appropriate numbered archives. If we can ascertain that there are no more incoming links to them, they could be deleted. — JFG ^talk 16:56, 23 August 2018 (UTC)

Crumbs are now all cleaned up. Thanks for help JFG! NewsAndEventsGuy (talk) 21:50, 29 August 2018 (UTC)

@JFG: you just changed the size of the figures in the article. I assume that absolute sized figures lead to problems on different devices?? Is there a way to make the figures somewhat bigger without using absolute sizes? Some of the figures would definitely benefit from being somewhat bigger. Femkemilene (talk) 10:41, 24 August 2018 (UTC)

Yes, please keep the previous sizes, the sorting changes are good. Also the lede image needs an update, additional for more context, an image with previous acceleration (last few years) should be added. prokaryotes (talk) 14:40, 24 August 2018 (UTC)

Yes, we are not supposed to specify absolute pixel sizes. If anything, my changes increased some sizes which were hard-coded, so I'm not sure which figures you would like to see bigger. Can you specify which ones you mean? — JFG ^talk 17:02, 24 August 2018 (UTC)

I think the first two ones need to be bigger, the one on the processes around the Antarctic ice sheet and the map of cities. I have difficulty reading them on my laptop at least. Femkemilene (talk) 17:35, 24 August 2018 (UTC)

I've made the top picture larger, as a good summary of the SLR trend for the lede section. The second one, about post-glacial rebound, looks good enough at standard size, and would overwhelm this short paragraph if bigger. The map of cities can not be saved by scaling up, lest we give it full screen width (and even there, it's hard to read because of a poor color choice). Either this map should re-drawn with larger dots for cities, or we could remove it entirely and replace it with a list of relevant cities. Note there is a full list of cities, with a 2007 OECD report cited as source, in the map's file description at File:Major cities threatened by sea level rise.png. — JFG ^talk 17:46, 24 August 2018 (UTC)

Also, for the lede image, it would look better if cropped to omit the small text at the bottom; the most relevant parts of this text should be reflected in the image caption. — JFG ^talk 17:50, 24 August 2018 (UTC)

Yes, crop the small text. If it is needed for understanding the graph it can be put into a note.

As a general note: I think figures (etc.) should always be large enough to read the text, especially axis labels. ♦ J. Johnson (JJ) (talk) 20:14, 25 August 2018 (UTC)

@JFG: thanks for that. I might remake the first figure and the cities figure myself. The first figure is in inches at the moment, so not really clear to an international public. Could solve this by adding a caption, but don't like the figure in general, so might as well make a better one. Femkemilene (talk) 07:30, 26 August 2018 (UTC)

First graph looks much cleaner now (File:Evolution-of-GMSL-time-series-from-six-different-groups’.jpg), thanks Prokaryotes for uploading it. I do agree we should be consistent with units of measurement. As this article discusses a worldwide phenomenon, MOS:UNITS mandates the use of SI units throughout, with imperial units converted when necessary, or kept when directly quoted from sources. More subtly, we should avoid mixing millimeters, centimeters and meters in prose and in graphs, because that creates misunderstandings about the order of magnitude of events. I'll work on that. — JFG ^talk 06:16, 30 August 2018 (UTC)

User:Prokaryotes: you recently added information about the marine ice cliff instability, which I believe is important. The previous paragraph is about the marine ice sheet instability, which I believe is better established. I think mentioning the slopes of the cliff is confusing, as this is not part of the ice cliff instability, but instead the mechanims behind the ice sheet instability. Could you correct your grammar + write an explanation that does not confuse the two processes? Here a paper explaining both: https://www.nature.com/articles/s41467-018-05003-z. Femkemilene (talk) 09:02, 29 August 2018 (UTC)

I have clarified these parts in more detail, there is room for a dedicated article, unless it is decided to merge it into the existing ice sheet dynamics article. prokaryotes (talk) 13:42, 29 August 2018 (UTC)

Re this edit, Femkemilene can you point out what is wrong, didn't you wrote it? If the newly added part on meltwater and surface lid conflicts, maybe just move that part? prokaryotes (talk) 00:23, 30 August 2018 (UTC)

The processes described are okay, it's just that those processes are not called the marine ice sheet instability. This type of instability is when you have a retrograde sloping surface. I'll edit it myself. Femkemilene (talk) 07:53, 30 August 2018 (UTC)

I've shortened the explanation so that it does not get undue weight in the article. I've removed the information about the meltwater acting as a lid, as the importance of this process is somewhat controversial and ice sheet dynamics is the proper location to go in all the details of the dozen processes that go on in ice sheets while they are melting. Femkemilene (talk) 09:07, 30 August 2018 (UTC)

a) I think we should mention the terminology of grounding line, which appears everywhere when this topic is discussed. b) In regards to cliff stability I prefer Pollard et al 2015, emphasis is this, "Increased oceanic melting at the base of floating ice shelves causes thinning and reduces their buttressing effect (back stress) on interior ice, and if the bed deepens upstream, this can lead to runaway retreat due to the very strong dependence of ice flux on grounding-line depth – termed “Marine Ice Sheet Instability” (MISI) (Weertman, 1974, Mercer, 1978, Schoof, 2007)" Currently the article only mentions the retrograde slope, and if part of the ice sheet melts. Also I would put emphasis on grounding line retreat + slope deepens, instead of increased thickness, unless we explain ice cliff stability in relation to ice sheet thickness with the related threshold of ~800 m. c) can you point me to something discussing your mentioned controversy, I am unaware. Will add that part later to the ice sheet dynamics page. prokaryotes (talk) 10:10, 30 August 2018 (UTC)

Your new version does not explain the process of cliff failure, this is too simplistic ..melt leads to additional ice flow. prokaryotes (talk) 10:37, 30 August 2018 (UTC)

a). I have a slight preference for not mentioning it. Trying to avoid jargon where possible. If you feel strongly about it, you could add it back. Do keep the length and balance of the total article in mind.

b) I now understand why you keep on using the wrong definition of marine ice sheet instability (including in the new article). Pollard's sentence can be interpreted in two ways.

Way 1, (your way): processes that lead to runaway melting

Way 2. (my way, and I strongly believe the correct way): the runaway retreat do to deepening of the bed upstream. While Pollard's sentence is ambiguous, the paper I sent you previously (https://www.nature.com/articles/s41467-018-05003-z) is not. The papers cited by Pollard (I read Weertman and Schoof) are also very clear in their definition of marine ice sheet instability. It is defined to be the instability due to the deepening bed.

c) Our article already mentions the controversy to some extent in the sentence: "However, Greg Holland from the National Center for Atmospheric Research, who reviewed the James (Jim) Hansen study, noted “There is no doubt that the sea level rise, within the IPCC, is a very conservative number, so the truth lies somewhere between IPCC and Jim.”[66]. Hansen paper itself (if i remember correctly) also mentioned they are not sure how big the effect is. They claim it could possibly be very large.. I'm not against re-adding it as long it is not given undue weight (say, maximally 1 sentence, no quotes). The paper is now described both here and at projections, so that was one of the reasons I deleted it here. If you can find a better balance, please do.

d) The cliff instability is mostly the fact that the ice shelves become unstable, which is summarily explained. If you feel you can improve it, again without giving undue weight to this particular physical process, please do. Femkemilene (talk) 16:43, 30 August 2018 (UTC)

Shall we try to keep a consistent citation style in this article? I have a preference for not mentioning names in the main text (Baker et al (2001) said X), but using the superscript style instead because (a) names are not sources of information people come looking for and therefore make it more difficult to read actual content (b) Names imply, to me at least, that the statement is dependent on the opinion of the author. With good reliable sources, this shouldn't really be the case. If if it too controversial, better not mention it except when it's extremely important. (c) Names are already mentioned in the reference section. Femkemilene (talk) 11:19, 23 August 2018 (UTC)

• Support standard wiki reference citiation templates with all the info in the "reference" section is best on this platform. NewsAndEventsGuy (talk) 12:36, 23 August 2018 (UTC)
• Support I won't mind having names, but also do not object to this mentioned CCS, thus support. prokaryotes (talk) 15:41, 23 August 2018 (UTC)
• Support standard citation style (not Harvard), with references grouped at the end of the article. — JFG ^talk 16:43, 29 August 2018 (UTC)

• Comment re 'names'. Let's slow down and take a closer look at the situation. For sure: the citations here are in terrible shape, which really ought to be cleaned up. Which in turn invites a general discussion on "consistent citation style". But for the moment let's focus on Femkemilene's thoughts re "mentioning names in the main text".

Taking Femkemilene's points in reverse order: a full citation should include include the full name of the lead author and at least the first two or three coauthors, as authorship is the key element (along with date) of identifying a work, and the basis of reliability. Generally we don't need to mention authorship right in the text, though there are exceptions, such as when an "author" is so notable (such as the IPCC, or Michael Mann and Senator Inhofe in the context of the Hockey_stick_controversy) that they are notable even for general readers. In such cases (and in a quick scan I saw only one here, in the "Projections" section) it is best to use the author's full name. E.g.: "In 1981 Robert Hansen and others^[] predicted ..." (leaving out the report name), with the citation (short, as in "Hansen, et al., 1981", or full) in the note.

Femkemilene: your comment (b) is troubling. All statements of supposed facts are, largely, "opinion", but the opinions of experts, vetted through the edtiorial and peer-review process, are a class apart from the general run of opinions, and not to be disdained. The "names" of the authors is how we identify a work, and really is a key part of what makes a source accepted as good and reliable. As to putting the details of the sources of information into the actual content: of course not. That's what the notes are for. ♦ J. Johnson (JJ) (talk) 20:27, 29 August 2018 (UTC)

This debate is drifting off into realms of abstractness which would be better suited somewhere in the Wiki Project namespace. I don't necessarily agree with all the statements here, but it isn't really the place to debate the abstract fine points of citation in general. NewsAndEventsGuy (talk) 20:57, 29 August 2018 (UTC)

Let's indeed not discuss this further, I feel we're all on the same page. Try to do consistent Wikipedia-style references. @J. Johnson, as a publishing scientist I of course value scientific articles as more than a simple opinion. A lot of Wikipedia articles give the impression they don't though and just publish a string of statements from scientists instead of speaking in the Wikivoice, which comes across as less reliable than should. Femkemilene (talk) 21:39, 29 August 2018 (UTC)

Hey, I didn't even get close to the "abstract fine points of citation in general" (as NAEG puts it); I was addressing (with a concrete example, no less) specific comments which bear on the actual work you are doing.

As the citations here are in really bad shape, and as you are putting in some major effort to remedy that, it would seem most opportune to consider "consistent citation style". And I think it would be easiest if all the full citations (considering their number and complexity) were pulled out of the text and put into the "reference" section (as NAEG says) "at the end of the article" (per JFG). But I have a feeling that may not be precisely what these guys really have in mind. JFG also says "not Harvard", but ambiguity runs rampant: does he mean not Harvard style referencing? Or not Harv templates? The problem is that many, many WP editors confound these two. "Harv" templates are for creating short-cites, and avoid the short-comings of named-refs (and the abominable {{rp}}).

Even with the best of sources, shoddy referencing (citation) of those sources suggests lack of care by the editors, to the detriment of the article. ♦ J. Johnson (JJ) (talk) 22:38, 29 August 2018 (UTC)

Recalling our climate page history with IPCC and HARV templates you built a few years back, I can't help but wonder if you're testing the waters here JJ, but just in case I am Opposed' to using Harv anything. I have never understood it, have never seen the value of it, did not understand your presentaation in the past, and I don't want to take time away from researching RSs to try again. For my whole wiki career the drop down citation templates in the editing window have worked just fine. NewsAndEventsGuy (talk) 23:19, 29 August 2018 (UTC)

"RSs"? I presume you mean "how to do citation". Well, I have studied the matter, and found that the various problems and issues inherent in our standard so-called "style" are quite unnecessary. But it seems the mass of Wikipedia editors are like you: having learned (perhaps at some cost) how to do "referencing" in some way that gets passed ("good enough"), you have become inured to the problems, and flatly refuse to do any more learning.

Why is it that you (and so many others) flatly oppose "Harv anything"? Is there such hatred of Harvard referencing style that it carries over to anything remotely connected with it? The "Harv" family of templates are the best way we have of doing short cites, and needs not get any closer to "Harvard" style than that. So would you feel any better about using short cites if the templates had a different name? ♦ J. Johnson (JJ) (talk) 22:14, 30 August 2018 (UTC)

@J. Johnson: For clarity, I meant to use named references; sorry you dislike them. I understand the benefits of Harvard-style references when an article uses multiple citations from a book, which happens often in biographies. That does not seem to be a frequent occurrence in this article, obviating the need for changing the dominant citation style. — JFG ^talk 06:10, 30 August 2018 (UTC)

By my quick count there are 15 sources in this article that are cited more than once. Is that frequent enough?

A serious deficiency in using named-refs is the inability to provide different in-source locations (such as page numbers), which seriously hinders verification. On the other hand, where is it said that our "dominant citation style" forbids the use of short cites? What is the problem with them? ♦ J. Johnson (JJ) (talk) 22:17, 30 August 2018 (UTC)

Ah, maybe you don't know that problem is solved with judicious use of Template:rp. Works for me. The only question is a subjective one, as described in the documentation for that template. NewsAndEventsGuy (talk) 22:44, 30 August 2018 (UTC)

No, the problem is not solved, as {rp} is an abomination. But never mind that. What I would really (yes) like to know is: why are you so opposed to "Harv anything"? Does it carry a stink of Harvard reference style? Or what? ♦ J. Johnson (JJ) (talk) 23:53, 30 August 2018 (UTC)

Ain't broke and there's a lot of work to do. Your mileage may vary. This is going nowhere, so I'm done here. NewsAndEventsGuy (talk) 00:03, 31 August 2018 (UTC)

Same feeling. Considering {{rp}} an "abomination" or a "neat way to refer to pages" is in the eye of the beholder. — JFG ^talk 09:43, 31 August 2018 (UTC)

I think I can provide definite, objective bases for my views. Apparently you guys can't support your views, other than WP:JUSTDONTLIKEIT. And I guess that's where we leave it. ♦ J. Johnson (JJ) (talk) 20:46, 31 August 2018 (UTC)

Recap I think we have agreed we will use the drop-down citation templates (or their close cousins that are not in the dropdown menu) in a straightforward way, and call it a day. If that's true, can we please close this thread? If it's not true can someone please state the proposal or question in twenty words or less? NewsAndEventsGuy (talk) 23:15, 29 August 2018 (UTC)

Can someone please post a citation for reference, thanks. prokaryotes (talk) 00:04, 30 August 2018 (UTC)

Based on time of my typing, you added one yourself in your most recent article edit NewsAndEventsGuy (talk) 01:13, 30 August 2018 (UTC)

Ah okay, thanks, thought it is something new :) prokaryotes (talk) 01:36, 30 August 2018 (UTC)

I took the liberty to improve this citation thus:[1]

• Use {{cite news}} instead of {{cite web}} when citing a newspaper
• Add author's first and last name
• Link to the publication's own article: The Guardian
• Replace year with exact date of publication; add |access-date=
• Add spaces between parameters to ease further editing

I think it would be beneficial to readers and editors alike if we'd adhere to those principles throughout. — JFG ^talk 06:06, 30 August 2018 (UTC)

Well done and said NewsAndEventsGuy (talk) 10:19, 30 August 2018 (UTC)

I just reverted this edit which added this text

In 2018 the impacts of sea level rise are already strong on the eastern coast of United States. In some areas the effects are strengthened by the weakening in the Gulf Stream what may be also related to climate change, changes in North Atlantic oscillation and the El Niño, so the rate reaches an inch per year. In some areas the beaches are eroding by 10 feet (3 metres) annually. In Nags Head beaches are eroding by 2 metres (6 feet) per year, so the town is spending 48 million dollars to nourish the beaches and raise the taxes for it. But nourished beaches are eroded at least two times faster than natural^[1][2].

There are multiple issues here. The most important issue has to do with the 1 inch/year number. The cited sources have their own links, so I dug and found the original study, "Spatial and temporal variability of sea level rise hot spots over the eastern United States". The first problem is that this text implies seas are going up an inch per year and will stay like that. In reality, the sources are talking about temporary "hot spots" that appear along different parts of the coast. The study says they haven't been sure why, and these scientists think El Nino' drives most of the rise and the Atlantic oscillation mostly determines where that rise shows up along the coast. A news tease say this runs in contrast to the prior speculation that it was tied to climate change and slowing thermohalince circulation. That's also what this ScienceDaily news story says. Another big problem is reporting beach erosion rates but not mentioning the complex factors including - as the sources say - that beach outlines and sandbars are always migrating. Overall, coastal impacts and regional variation is indeed something we need to carefully explain. But this paragraph needs substantial work.NewsAndEventsGuy (talk) 12:55, 26 August 2018 (UTC)

Thanks, NAEG :). User:אלכסנדר סעודה, please do not put your edit back before responding to these points. Also keep in mind that the article is already focussing disproportionally on the US, so try adding stuff that represents different areas of the world, as found in preferable international reliable secondary sources. Femkemilene (talk) 09:57, 28 August 2018 (UTC)

What I have writed is not contradicting the remarks of NewsAndEventsGuy. I do not write " climate change cause sea level rise of inch per year in the eastern coast of USA" exactly for the reasons that he mentioned. That is why I writed "in some areas" "strengthened by". Also you know that there is a section "regional sea level rise" in the page who talks about the link between climate change, weakening of the AMOK and extreme sea lever rise events on the eastern cost of USA. The study who talks about the link is this

An extreme event of sea-level rise along the Northeast coast of North America in 2009–2010.

They say in the chapter "Results"

" Future projections of extreme SLR events

Similar to extreme temperature and precipitation events, extreme SLR events on the interannual time scale may be also linked to human-induced climate change35. Increased greenhouse gas concentrations are likely to shift the probability density function towards more extremes. To study future changes of extreme SLR events, we consider the ten GFDL climate models and their long-term control runs, and idealized 1% per year CO2 increase experiments for 100 years. Along the NE coast of North America, most of these models (CM2.6, CM2.5, CM2.5 FLORa6, CM2.5 FLOR, ESM2M and ESM2preG) suggest an increase in the magnitude and frequency of the extreme SLR events in response to the CO2 increase (Fig. 5 and Supplementary Fig. 14). In five of these models (CM2.6, CM2.5 FLORa6, CM2.5 FLOR, ESM2M and ESM2preG), the increase in the yearly SLR extrema is unproportionately larger than the increase in mean sea level (Supplementary Fig. 14)."

So it probably "will stay like that".

As you can see from this summary

Flooding Hot Spots: Why Seas Are Rising Faster on the U.S. East Coast

The scientists talk about 3 causes to the extreme sea level rise: Gulf stream, El nino and North Atlantic oscillation - exactly what I have writed.

The facts that say that sea level rise are linked with the slowing of the gulfstream are not speculation - they have been proved in peer reviewed studies.

In 22 August this year a new study said, what climate scientists said a long time a go: Climate Change make El nino stronger.

ENSO's Changing Influence on Temperature, Precipitation, and Wildfire In a Warming Climate

So, he can add that not all studies support it, but he have no right to delete. About the link between sea level rise and cost erosion, also, he can add that the coast line always move, but according to most studies, modern beach erosion is strongly linked to climate change. He should not delete it. He is right about the sources: next time I will put the original studies.

--אלכסנדר סעודה (talk) 08:33, 12 September 2018 (UTC)

Please see WP:THREAD, and WP:SECONDARY. More concerning, in reply to "he has no right" please review WP:CONSENSUS and WP:Assume good faith. Most concerning, is your bolding "So it probably 'will stay like that'." Clearly, you have a strong opinion about the implications of this WP:PRIMARY source. We don't add text based on what we infer because that is prohibited WP:Original research. NewsAndEventsGuy (talk) 12:02, 12 September 2018 (UTC)

In this edit Femkemilene added some nicely explained text about sediments and mangroves. Of the three RSs, this one is paywalled, and from the abstract page it isn't clear that this article really encompasses sediments and mangroves, as opposed to sediments and other habitats. So I couldn't verify this part of the paragraph. (The rest is great, thanks.) F, when you have the chance, could you please ensure that the RS I linked here really supports the text you added? For context, please review the English Wikipedia's understanding of WP:SYNTH. We want to make sure we don't do that. Thanks NewsAndEventsGuy (talk) 07:52, 7 September 2018 (UTC)

Will do once I have time. A mangrove forest is a form of tidal wetland if I'm not mistaken, but will double check if they are mentioned explicitly. Femkemilene (talk) 20:35, 10 September 2018 (UTC)

In terms of synthesis; I try to avoid it, but I don't think it's completely avoidable. I have not been able to find a single source with all the effects of SLR, so I have to make some value judgement about the relative importance of different sources. In terms of mangroves; they are very often studied are have a maybe disproportionate weight in google scholar/web of science results because of that. Of course the synthesis of adding source A and B by logic for unsupported conclusion C is avoidable and will double check whether I've done that here. Femkemilene (talk) 20:35, 10 September 2018 (UTC)

Double checked and you were right, the article did not mention mangroves explicitly. For future reference, you should never use Sci-Hub to get access to scientific results that are paid for by public money and then paywalled by companies making huge profits. Femkemilene (talk) 15:35, 30 September 2018 (UTC)

An awesome aphorism, thought a bit wordy for bumper-stickers NewsAndEventsGuy (talk) 13:49, 1 October 2018 (UTC)

Article talk pages are not for general discussion about the subject of the article.
The following discussion has been closed. Please do not modify it.
These models assume ice melt is linear when in fact ice melt is exponential. Ice melt is a complicated subject but fundamentally it melts away from the heat sources which are primarily on top and bottom so the ice thins. Heat transfer through ice is not instantaneous so you get surface melt. You basically have the same surface area exposed to the heat sources so less and less ice has to absorb the same amount of heat. The ice that is remaining is absorbing more latent heat needing less and less additional heat to make it melt and that is exponential. If you're not familiar with an exponential curve you win the Lottery. They give you the choice of 3 million dollars in hand or a penny the first day two pennies the next doubling it each day for 30 days (exponential), which one would you choose? Where are we in an exponential curve? The data would suggest we're right where the exponential curve start heading to the stratosphere. James B MacDonald — Preceding unsigned comment added by James B MacDonald (talk • contribs) 20:33, 13 October 2018 (UTC) James Brian MacDonald 15:12, 14 October 2018 (UTC)

User:Distelfinck just removed some information about hard and soft adaptation strategies, because apparently there is a more common definition of hard and soft. I'm willing to believe I made a mistake here; I'm not an expert in the nonphysical side of sea level rise. Having come across the term multiple times, I do think it is important to include the correct definition in the article though. What other definitions are around and which sources support that different definition?

(For reference, the text that was removed: These adaptation options can be further divided into hard and soft. Hard adaptation relies mostly on capital-intensive human-built infrastructure and involves large-scale changes to human societies and ecological systems. Because of its large scale, it is often not flexible. Soft adaptation involves strengthening natural defenses and adaptation strategies in local communities and the use of simple and modular technology, which can be locally owned. The two types of adaptation might be complementary or mutually exclusive. The building of a dike (hard adaptation) for instance destroys the natural dune system and dune nourishment will not be possible anymore.^[1][2]). Femkemilene (talk) 21:19, 4 December 2018 (UTC)

Actually, not sure if this stuff is relevant enough to be included (I mean, this terminology doesn't seem to be used that often -- very few search results) --Distelfinck (talk) 22:27, 4 December 2018 (UTC)

I restored this well-referenced neutrally-stated text because there was no weighty reason for removing it. See Arguments to avoid when discussing article content . NewsAndEventsGuy (talk) 19:05, 5 December 2018 (UTC)

Eh, I actually looked at the sources and some of the article text is only sourced by one of the sources at most. So what's the relevancy here? That one author uses the terminology? I looked for other sources and found the OECD, who uses the same term with another meaning. --Distelfinck (talk) 19:58, 5 December 2018 (UTC)

The first source is paywalled. I have access to the whole thing. Except for the last line the entire paragraph is supported by the first source. The last sentence looks like original research. The second source does talk a lot about dikes and beach nourishment, but does not say a dike destroys natrual dune systems or prevents dune nourishment. I'll remove the last sentence but I'll keep the second reference which supports the distinction of hard v soft adaptation described here. Besides the OECD there are other sources that use these terms, including IPCC AR2. In AR5 they seem to have saved "hard" and "soft" to describe the limits of adaptations rather than classes of adaptations. NewsAndEventsGuy (talk) 00:58, 6 December 2018 (UTC)

The beginning of the lead establishes cm as the dominant unit, at least below 1000 cm.

So there are two problems with the sentence below:

For example, in 2007 the high end of Intergovernmental Panel on Climate Change (IPCC) projections through 2099 was less than 2 feet (0.61 m), but in their 2014 report the high end was considered to be about 3 feet (0.91 m).

The first is that it's disruptive to be switching here into feet (though perhaps this is to honour the source, which in any case I would regard as actually more of a disservice to the reader than benefit to the source) and the second is that the metric units should be glossed (if they must be glossed) in cm to remain consistent with the previous metric units introduced, rather than meters.

The IPCC is a body of the United Nations. Maybe they put out one version of the report in Imperial units for a certain affluent, but proudly ostracized audience, though surely metric is their own native unit internally, and primary unit in most of their publications. — MaxEnt 18:27, 6 December 2018 (UTC)

I have re-written the lede paragraphs to use centimeters as the base unit throughout, except for the latter extreme long-term predictions which are better understood in meters. I also clarified some sentences to ease understanding for a lay reader. — JFG ^talk 22:03, 6 December 2018 (UTC)

I think the article is almost ready for a good article nomination. Here a list of the criteria, and what I think we should still do before nominating the article.

1. Well-written:
   1. the prose is clear, concise, and understandable to an appropriately broad audience; spelling and grammar are correct; and
   2. it complies with the Manual of Style guidelines for lead sections, layout, words to watch, fiction, and list incorporation.^[1]
2. Verifiable with no original research:^[2]
   1. it contains a list of all references (sources of information), presented in accordance with the layout style guideline;^[3]
   2. reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose);^[4]
   3. it contains no original research; and
   4. it contains no copyright violations or plagiarism.
3. Broad in its coverage:
   1. it addresses the main aspects of the topic;^[5] and
   2. it stays focused on the topic without going into unnecessary detail (see summary style).
4. Neutral: it represents viewpoints fairly and without editorial bias, giving due weight to each.
5. Stable: it does not change significantly from day to day because of an ongoing edit war or content dispute.^[6]
6. Illustrated, if possible, by media such as images, video, or audio:^[7]
   1. media are tagged with their copyright statuses, and valid non-free use rationales are provided for non-free content; and
   2. media are relevant to the topic, and have suitable captions.

1. Well written
   • Fine
2. Verifiable
   • I think I've checked 90% of the sources, will try to go over the rest
3. Broad in its coverage:
   • Sometimes there might be too many details, mostly about number (why is it interesting to know that exactly 68 of beaches in one small area of the world have erosion, a phenomenon that is only partially caused by sea level rise
4. Neutral
   • I think the article is quite neutral. Some final decisions about what to include in the projections section should be made, preferably by still staying focused and not including too many sources (conciseness).
5. Stable
   • Fine
6. Media
   • I think copyright state is automatically checked, but will double-check.

Femkemilene (talk) 08:41, 13 October 2018 (UTC)

@Femkemilene: Thanks for all your hard work. I have improved the prose to clarify some facts for lay readers, especially in the lede section that suffered from inconsistencies in units. I have also added some citation needed tags in locations where they are missing. Even if it may sound obvious that coastal cities are particularly vulnerable to sea level rise, every statement in the article should be backed by RS. I'd be happy to help with further copyediting towards GA approval. — JFG ^talk 23:12, 6 December 2018 (UTC)

Thanks. I'll try to find the references around Christmas/modify the text if no RS can be found. Further copyediting would be really appreciated :). Femkemilene (talk) 14:55, 7 December 2018 (UTC)

Just echoing JFG... thanks! NewsAndEventsGuy (talk) 01:12, 8 December 2018 (UTC)

With all the citation needed tags addressed, I think the article is ready for nomination. I will read the entire article one more time and might nominate it in the next couple of days. Femkemilene (talk) 15:18, 28 December 2018 (UTC)

There was a section on extreme slr events, which I think should be re-added because it appears significant if larger parts of ice sheets begin to disintegrate, or there are more similar events. See the section here. prokaryotes (talk) 17:07, 15 January 2019 (UTC)

I think that there is good material for this in the literature. The previous section I mostly deleted because it was poor and overly specific. I think I remember some more global and reliable sources mentioning extreme SLR events as well. I'll refer to NCA and IPCC for correct heading and placement. Femkemilene (talk) 10:21, 16 January 2019 (UTC)

Thanks for your continued work here, Femkemilene. In an edit summary you wronte science of SLR progresses fast; estimates done in 2010/2011 not relevant. There is an aspect that I've always believed to be highly relevant.... plotting old projections over time. When you drill down into the details of old projections, a story unfolds of (A) how we learned some things while learning that we did not know things (the so-called "known unknowns"), (B) as the known-unknowns become quantified the projections consistently go up, and (C) ... this might be redundant.... but over time the big reports with updates projections seem to keep going up. So the old projections aren't entirely meaningless. Just to be clear, I'm not objecting to your recent deletion of some of the old projections. Just saying that the data underlying the deleted text is useful in other ways and we should be open to using it in another context. NewsAndEventsGuy (talk) 12:39, 28 December 2018 (UTC)

I've tried to keep the information in that the estimates have been revised upwards because of addition of more physical processes. The processes involved are partially described in the contributions section. I agree plotting old projections over time is quite interesting, but because I can't find a source doing something of that kind (I've tried to find one, but Twitter and Google couldn't help me find a history of SLR research) stringing this info together feels like OR to me. Sources usually compare themselves only with the previous iteration/previous important study. If you can find a good source for your (A) and (B) you'd make me quite happy. An other important reason I deleted it, is to prevent an avalanche of different numbers and estimates that make the text less rather than more informative. Femkemilene (talk) 14:04, 28 December 2018 (UTC)

OK, and FYI, in my earlier comment, I should have mentioned this section. NewsAndEventsGuy (talk) 14:20, 28 December 2018 (UTC)

I just wanted to make the same point as NAEG, I agree that we should not discard older estimates. Because they showcase how we have underestimated the rate of change. prokaryotes (talk) 16:56, 15 January 2019 (UTC)

There is two reasons I am careful not to include too many old estimates. 1. The article should not be made too complicated. Complicated articles hide useful content in clutter and are a pain to maintain. Secondly: we need a reliable source for the conclusions we make from a series of estimates. The IPCC typically only reflects on changes from its last report and is not helpful as a source for larger historical comparison. We are not the people to make this synthesis of of the available literature. As I find it interesting personally, I have searched for literature that gives an historical overview, but have not been able to find it, nor were people on my Twitter feed.

You have readded a study by Hansen. This introduced two inconsistencies in the article

A) The Hansen study is not the original study, but only cites the Mendel study, which I have included. The same study is now mentioned twice, without that being clear at all.

B) the headings are now incorrect. Where the 20th century refers to predictions made IN the 20th century, the 21st and long-term projections refer to the period ABOUT which predictions were made. I've pointed this out before. This error could have been prevented if you had carefully read my comments when editing or the paper. Femkemilene (talk) 10:17, 16 January 2019 (UTC)

You mean the 1978 Mercer study, okay. Thanks for pointing this out, and sorry I do not read every of the hundreds of edit summaries. prokaryotes (talk) 10:54, 16 January 2019 (UTC)

Don't worry, I don't expect you to read all my edit summaries. I would only appreciate it that you try to find them when you're undoing one of my edits :). Of course I make mistakes, but I do make an effort to explain each change to the article and that effort seems a bit pointless when it seems to be ignored, hence the grumpiness. Femkemilene (talk) 11:07, 16 January 2019 (UTC)

When one regular is editing work of another regular, I ___do___ expect them to read edit sums... or just ask... Saves a lot of time and makes better relations. When I want to find a change in a long list, I do a binary search. Comparer 2015 to 2019. The change happened? OK, compare 2015 to 2017. No change? OK it must have been in the later half of the first search. Keep splitting the interval in half and quickly find the relevant tweaks. Study diffs before and after in case there was a series that day. NewsAndEventsGuy (talk) 12:02, 16 January 2019 (UTC)

You might be aware already, but there is an ill-named tool for that: http://wikipedia.ramselehof.de/wikiblame.php Femkemilene (talk) 12:10, 16 January 2019 (UTC)

Thanks, I did know about it. Your mileage may vary.... I prefer the manual binary search because for me its just as fast plus by simply backing up a screen once you find the right diff, you see the whole series by all eds at that time. So you get not just the pinpoint but the evolution. But hey, whatever floats your boat! NewsAndEventsGuy (talk) 14:49, 16 January 2019 (UTC)

The lead section is not bad but does not meet Wikipedia requirements. MOS:LEADELEMENTS It should be short and precise about what the subject is and is not. The title should be included in Bold type. Rlsheehan (talk) 19:12, 7 September 2018 (UTC)

(A) On the subject of bolding, that's not necessarily correct. The MOS says don't struggle with awkward language just to turn the title into the subject of the first sentence. See Wikipedia:Manual_of_Style/Lead_section#First_sentence and several subsequent sections on using bold.

(B) Besides that, thanks for your generalized comment but could you be more specific? If you have identified mismatches between the lead summary and the body of the article, please tell us what those mismatches are. Merely asserting that mystery mismatches exist does not help us address the claimed issue. NewsAndEventsGuy (talk) 19:51, 7 September 2018 (UTC)

The MOS says:"If possible, the page title should be the subject of the first sentence". That is easily accomplished and was done so in wording up to 24 August.

Sea level rise (SLR) is the increase in global average sea level as a result of an increase in the volume of water in the world’s oceans. Current sea level rise is mostly attributed to global warming by thermal expansion of the water in the oceans and by melting of ice sheets and glaciers on land.[2] In the period afterwards (1993-2017), this accelerated to 3.0 ± 0.4 mm per year.[3]

That wording seems simple and clear. Readers know what the article is about. I suggest we go back to that wording or something similar. Rlsheehan (talk) 20:41, 7 September 2018 (UTC)

Opposed. As a matter of consensus, WP:CONTENTAGE is irrelevant, and in this case the old language you want to go back to is grammatically circular... Sea level rise is increasing sea level. Surely we can do better. The new attempt may not be perfect, but it's better than saying "rising sea level is increasing sea level". Our #1 objective is to write something useful and engaging for our readers and you make what I think is the key point... readers already know what this article is about. Remembering that Wikipeida is WP:NOTBUREAUCRACY, what problem are you trying to fix? There is no mandate that the article title form the subject of sentence 1, nor that it be bold in sentence 1. On the contrary, the MOS allows for cases where that would just be awkward. My goal is to avoid awkward writing like circularity, so the product is both useful and makes engaging reading. Can you think of a third version that might satisfy both of us? NewsAndEventsGuy (talk) 21:54, 7 September 2018 (UTC)

PS Thanks for your efforts on the article last year. I think I was on Wikibreak then, or I probably would have replied. NewsAndEventsGuy (talk) 22:00, 7 September 2018 (UTC)

a) Article should start with Sea level rise ... b) Sea level rise is already accelerating. The article count is ten mentions for acceleration, should be clear in this regard. prokaryotes (talk) 10:11, 8 September 2018 (UTC)

• In response to the banner: shall we remove it? This is a discussion about language, not the content of the lead section.
• I have a slight preference for the wording of NAYG, but don't mind the slightly circular definition either.
• If I understand it correctly, something like: Sea level is rising as a consequence of... is not allowed by the rule, right? Synonyms are allowed to be boldfaced, but if you change the grammatical construction, boldface should not be applied?
• In response to Prokaryotes: a) Would be nice, can you formulate a non-circular sentence though? I'm not able to. b) . Do you have a better proposal? I'm not sure we want to mention both the past acceleration and future accelation in the second sentence, that would be too dense. If you can find some nice sentence with both in I'm in favor. Femkemilene (talk) 20:30, 10 September 2018 (UTC)

Currently a little busy, but this was the older version. Also glaciers do not necessarily raise sea levels, due to human land use changes, water management... (can be checked here) also should mention marginal attribution from sea ice/floating ice (?). Maybe next days if I have more time I make a revision. prokaryotes (talk) 13:31, 12 September 2018 (UTC)

I don't have a lot of time atm, I think we should re-add the previous version. prokaryotes (talk) 19:33, 20 September 2018 (UTC)

Disagree. Now what? NewsAndEventsGuy (talk) 20:27, 20 September 2018 (UTC)

I'll propose a compromise sentence. Less of a circle-reasoning compared to old version, but including boldface. It is more awkward than the sentence proposed by NEAG.

For at least a century global warming has been driving thermal expansion of seawater and melting land-based ice sheets and glaciers, which in combination with changes in land storage leads to sea level rise.

Trying to formulate a sentence myself, I'm becoming more in favor of the current sentence. Femkemilene (talk) 07:38, 21 September 2018 (UTC)

While I do appreciate the effort, Femkemilene, your suggested alternative only tells the how, not the what. The meaning of "sea level rise" does not enjoy the same degree of obviousness as WP:SKYISBLUE. NewsAndEventsGuy (talk) 13:32, 21 September 2018 (UTC)

The lead section needs to start at a basic elementary level. Many people do not have a background here. Half of Americans reject climate change and associated sea level rise. Our government has cut money for observation and research. No, this is not an "obvious" topic. We need a good lead paragraph.Rlsheehan (talk) 13:04, 27 September 2018 (UTC)

@RLsheehan: do you think there are sentences that are too difficult in the lede? Could you specify which and possibly propose simpler sentences? (On a side not: your assertion that half of Americans don't believe in global warming is not entirely true: a 2016 Gallup poll showed that 65% believe humans to be the primary cause: https://news.gallup.com/poll/190010/concern-global-warming-eight-year-high.aspx)

@NEAG: You're right, your sentence is definitely better.Femkemilene (talk) 18:32, 28 September 2018 (UTC)

I've removed the banner. Not saying the lede is now perfect and suggestions for improvements are of course still welcome. At the moment it does summarize the article and satisfies all requirements. Femkemilene (talk) 18:32, 28 September 2018 (UTC)

The first reference in the lead is a) from 1997, b) is behind a paywall, and c) the abstract makes no mention of the statement being made in the article. I am uncomfortable with the use of the word "about" in the lead's first para (twice) when referring to measurements. It is ambiguous as to whether "about" means the measurements are uncertain, differ between ensembles or has been rounded. I am just flagging this because I read the first para, and thought: "wait, what?". I am happy to go looking for a set of free access supporting references (rather than just one) for some of the lead's claims ... but I'm still a very new editor. I have experience at the tertiary education level, but am still learning WP's guidelines and rules. By all means, stop me if I'm going down the wrong track here. Thanks to all, commenters here in talk and those who've worked on this article to date. Prime Lemur (talk) 13:07, 25 November 2018 (UTC)

Thanks! I agree that the rise we have had should be supported by a more modern source, preferable not behind a paywall. I also agree that the word about is ambiguous. When editing the lede, please do make sure that scientific precision doesn't interfere with how easy it is to understand for a layperson. Femkemilene (talk) 10:52, 26 November 2018 (UTC)

I've replaced the first reference with a modern estimate. It seems that current estimates of 20th century SLR are a bit lower. The estimate in inches is also rounded to whole numbers in the source, meaning that the estimate in cm in more precise. I find it quite annoying that sources use both the word about and uncertainty estimates, but I'll just copy their word use.Femkemilene (talk) 13:37, 18 January 2019 (UTC)

(continuation from previous discussion, that went off track)

Femkemilene, please confirm that we should not point out linear vs exponential trends in models. Notice also that it is perfectly fine to post technical comments on article talk pages. prokaryotes (talk) 13:41, 18 January 2019 (UTC)

None of the current modelling strategies (complex GCMs, SEMs or Hansen's paper) have a linear trend I don't think, so indeed we should not point that out. All have acceleration, the difference is how much. This translates to different prediction of SLR in (2050 and) 2100, of which there I think we have good overview focusing on estimates after IPCC AR5 (different techniques: Hansen's exponential paper, a SEM and two systematic reviews).

Onedown is a useful way of thinking about how easy to make it! Femkemilene (talk) 13:58, 18 January 2019 (UTC)

Weren't projections linear at one time? I thought IPCC said something like SLR by 2100=59cm extending a linear trend of past observations of mostly thermal expanison..... but subject to dynamical ice sheet changes which we can't include due to lack of understanding.... that was the 2000 or 2007 report, I think. Am I remember that right? Kind of related.... if we don't have a gripping way to show how projections have changed over time that might be a high impact graphic waiting to be createdNewsAndEventsGuy (talk) 15:02, 18 January 2019 (UTC)

(I think there is consensus not to mention the words linear and exponential, so this is for information sake). I was referring to the different current estimates when I said no estimate is linear. I've never seen a mention of linear increase, but I'm sure there are some near-linear estimates to be found. The TAR says the following about thermal expansion (with other contributions being very uncertain and smaller) : thermal expansion of 0.11 to 0.43 m, accelerating through the 21st century. With estimates having increased in AR4, I assume they don't mention linearity either. Femkemilene (talk) 16:37, 18 January 2019 (UTC)

Thanks, I appreciate your patience and attention here. On the other thing... I also think showing how projections ahve changed over time is worth doing, if it hasn't been done already NewsAndEventsGuy (talk) 17:05, 18 January 2019 (UTC)

I think the linear discussions evolve around ice sheet dynamics, due to a lack of models to adequately produce response times. You get results when searching for ie. "linear response from ice sheet" prokaryotes (talk) 17:18, 18 January 2019 (UTC)

@NEAG There is one source I found when looking specifically for this. The paradigm shift in Antarctica, currently ref 49. I thought I made some general comment but apparently only mentioned their mention of the 1978 Mercer paper and changes since 2013. Will add a sentence to last paragraph of projections section from this reference for the period in between. I have not found (I have looked) a source on the history of overall SLR estimates over the years and I do not want to make a synthesis myself. I feel that that constitutes OR and that it's difficult to make it sufficiently easy.

@P that makes sense. We still agree that the current way of implementing is okay, i.e. mention current higher estimates, but not the specific mathematics (linear/nonlinear/exponential)? Femkemilene (talk) 17:23, 18 January 2019 (UTC)

I would certainly mention briefly that newer models better capture trends, and if those are exponential trends, then we should point this out. I do not know of any consensus to not mention the words linear and exponential. prokaryotes (talk) 17:32, 18 January 2019 (UTC)

@P We only violate WP:SYNTH when we string things together to present WP:OR that was not in the RS's in the first place. There is nothing wrong with making graphical presentation of RS data....FWIW....image policy encourages us to create new graphics that can pass WP:Verification. If the inspiration ever strikes, go for it NewsAndEventsGuy (talk) 17:34, 18 January 2019 (UTC)

@P. You want us to mention that newer models better capture trends. So far the introductions mentions a general new models are better. The model section mentions: "This type of modelling was partially motivated by the fact that in previous IPCC assessments most physical models underestimated the amount of sea level rise compared to observations of the 20th century". Do you want it to be more specific? If so, what concrete changes do you want? Femkemilene (talk) 08:57, 19 January 2019 (UTC)

When we have a grip on P's ideas, one possibility is to only add a little bit more here, keeping to WP:SUMMARY style, and add the graduate student level text at Climate model. This article has lots of traffic from a wide range of reader-ability. NewsAndEventsGuy (talk) 11:31, 19 January 2019 (UTC)

@NEAG. I'm afraid that if you string together a lot of old estimates, you automatically make a narrative of climate scientist are too conservative, maybe even implying that these estimates could go further up. If there is a reference explaining this in the context of SLR, I'm okay with dedicating a line to that. Femkemilene (talk) 08:57, 19 January 2019 (UTC)

An excellent point which the RSs already overcome. (A) Each individual projection is documented so it passes WP:Verification that way and (B) Others have already used evolving SLR projections to complain that in their view IPCC is too conservative. See Intergovernmental_Panel_on_Climate_Change#Conservative_nature_of_IPCC_reports.NewsAndEventsGuy (talk) 11:31, 19 January 2019 (UTC)

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This review is transcluded from Talk:Sea level rise/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Hurricanehink (talk · contribs) 19:30, 26 January 2019 (UTC)

I'll be reviewing this important article. I got up to the end of "Sea level measurement".

• 'At least since 1880, the average global sea level has been rising. - considering it's the fourth word, you should probably mention this fact somewhere else in the article, namely the 1880 bit. I'm not the biggest fan of the current wording for the first sentence, as I'd prefer to see "Since at least 1880", but I'm sure the wording is deliberate, so I won't be picky about that. Also, the article says before the recent rising trend starting approximately in 1850 - so is it 1880 or 1850?  Done
• Between 1900 and 2016 sea level rose by approximately 16 to 21 cm (7-8 inch). - add comma after 2016. Done Also, since it's the first time mentioning these units, they should be spelled out and linked.  Done
• The acceleration is due mostly to anthropogenic global warming that is driving the thermal expansion of seawater while melting land-based ice sheets and glaciers. - probably the most important sentence in the article (and arguably in our world right now). Perhaps link anthropogenic? I think a few more commas would be helpful, maybe say "warming, which is..."  Done The driving the thermal expansion is a bit odd to me, and even reading the link for thermal expansion, I didn't really get it. Is the water getting bigger? The article should be written for the laymen, and just having links might not be enough to make it understandable for everyone.

Hmmm. Water indeed takes up more volume when its temperature rises (except for fresh water of 4 degrees and below). I think it best to keep the term thermal expansion in the lede, but explain in the contributions section. I cannot think of a formulation that is simple, but not so simple people are put off. Femkemilene (talk) 22:00, 29 January 2019 (UTC)

• The current trend is expected to further accelerate during the 21st century. - expected by whom? Rather than having it in passive voice, perhaps say "Computer models and climate scientists expect the current trend to further accelerate during the 21st century."  Done
• Projecting future sea level has always been challenging, due to imperfect understanding of many aspects of the climate system. - I'm not a fan of the always here. Could you word it differently?

Is this better? Femkemilene (talk) 22:00, 29 January 2019 (UTC)

• Your units in the 2nd lede paragraph go from inches to ft. Please be consistent  Done
• The contributing factors to sea level rise between 1993 and 2018 are thermal expansion of the oceans (42%), melting of temperate glaciers (21%), Greenland (15%) and Antarctica (8%). - I feel like this should be with the bit in the first paragraph when you mention the thermal expansion and glacier melting.  Done
• Could the tiny 4th and 5th lede paragraphs be merged?

I've instead expanded the 4th paragraph a bit. I think it is important to keep these two things separately, because they are both important.

• In the recent geological past changes in land ice and thermal expansion from increased temperatures are the dominant reasons of sea level rise. - add a comma after "past"  Done
• 8.2 thousand years - please be consistent with how you handle these years. Why not just "8,200 years?"

The source does not provide four significant digits, but says 8.2 kyr. 8,200 years implies that we do know the precise year. Femkemilene (talk) 16:13, 30 January 2019 (UTC)

• Is an "altimetric satellite" should link to satellite altimetry when it's first mentioned.  Done
• with data for the Southern Hemisphere remained scarce up to the 1970s. - grammar  Done
• near the Port Arthur convict settlement in 1841. - ref? The reference was earlier in the sentence, not sure if it applies to all.  Done

Will finish later. ♫ Hurricanehink (talk) 19:30, 26 January 2019 (UTC)

Contributions

• Sea level rise in the last 150 years - at some point, this year will have to be changed. Elsewhere in the article, it says "Since X year". Please do the same here  Done
• but the contributions of the two large ice sheets (Greenland and Antarctica) is expected - shouldn't it be "are expected"?  Done
• If the rest of the ice returns to the ocean as icebergs and from melting at the edges then the icesheet remains the same mass and does not affect sea level. - please improve sentence structure  Done
• In terms of heat content, it is the world ocean that dominates the atmospheric climate. - odd sentence structure  Done
• The oceans store more than 90% of the heat in Earth's climate system and act as a buffer against the effects of climate change. For instance, an average temperature increase of the entire world ocean by 0.01 °C may seem small, but in fact it represents a very large increase in heat content. If all the heat associated with this anomaly was instantaneously transferred to the entire global atmosphere it would increase the average temperature of the atmosphere by approximately 10 °C.[35] Thus, a small change in the mean temperature of the ocean represents a very large change in the total heat content of the climate system. - this all sounds like it's written out of a textbook  Done
• The additional snowfall causes increased ice flow which leads to further loss of ice. - could you rewrite this?  Done
• , which holds enough ice to raise global sea levels by 53.3 m. - add ft  Done
• concluded that East Antarctica is losing significant amounts of ice mass. - the italics seems dramatic.  Done
• The researcher Eric Rignot - surely he could get a better introduction. He's a professor after all.  Done
• How big is the Totten Glacier? Might be useful to mention  Done

The size of the glacier itself is not really relevant. Relevant is what volume drains through it. Femkemilene (talk) 21:00, 31 January 2019 (UTC)

• 0.08 °C per decade and 0.96 °C per decade between 1976 and 2012. - please add Fahrenheit  Done
• A rapid collapse of the West Antarctic Ice Sheet could raise sea level by 3.3 metres (11 ft) at an unknown rate. - if it's at an unknown rate, is it worth mentioning?  Done
• Most ice on Greenland is part of the Greenland ice sheet which rises to an average of 2.135 kilometres (1.327 mi). The rest of the ice on Greenland is part of isolated glaciers and ice caps. - this is unsourced. Is it part of the following paragraph? If so, make it one paragraph.  Done

I think that claim came from different Wikipedia page, which had Encyclopedia Britannica as its source. Google scholar didn't provide a good alternative, so I'm now mentioning maximum height. The precision of that old estimate is completely unjustifiable anyway. Femkemilene (talk) 17:34, 2 February 2019 (UTC)

• Average annual ice loss in Greenland more than doubled in the early 21st century compared to the 20th century. - I gotta ask, but the early 21st century and the 20th century could technically be only two years apart. Some more context here would be good.
• 43% of current sea level rise is due to the Greenland ice sheet, its peripheral glaciers and ice caps. - I think there's a rule somewhere that you're not supposed to start new paragraphs with a number, but more importantly, are you deliberately not using the oxford comma here? Just checking.
• 1.32 mm per year - units  Done

Converting these things to inches looks weird (especially the smaller ones). I heard some people say US English speakers do use mm to subdivide inches? Femkemilene (talk) 21:07, 28 January 2019 (UTC)

Come to think of it, yea, I don't think there's a need if it's below 2 mm, since that is below 0.1 inches, and at that point, the mm is more effective. ♫ Hurricanehink (talk) 21:27, 28 January 2019 (UTC)

• Different research has put this threshold value as low as 1.0 °C, and definitely 4.0 °C - Fehrenheit too  Done
• The roughly 200,000 glaciers on earth are spread out across all continents. - how much mass, or how big of an area, are they? You said 1% vs 99%, but a figure here would be nice.

I will try to find a comparison in terms of area. I am not a big fan of numbers that people can't comprehend. Femkemilene (talk) 21:07, 28 January 2019 (UTC)

On second thought, I think this is a good location not to mention numbers. Article has too many of them as it stands. I think they melt so quickly that if I can find a number, it will be outdated very soon. Femkemilene (talk) 17:34, 2 February 2019 (UTC)

Models

• Why isn't the Models section part of Projections?  Done (Don't know why I didn't think about this myself)
• that in previous IPCC assessments - since you only mentioned it once in the lede, it could be good to spell out the acronym here, especially if you made this paragraph part of the lead for the next section  Done

Projections

• Why is there a 21st century section? Will there eventually be a section for 20th century projections? IF so, why isn't it there now? (I see it mentions 1978, so my suggestion is remove "21st century" and merge the "Models" paragraph into this section, and don't have a 3rd level sub-header until Long-term rise)

The idea is to have a section on medium-long projections (till 2100) and long-term projections. It's not about when the projections are made. I will change the subsection to Projections for the 21st century.

• This could mean rapid sea level rise of up to 19 millimeters per year - units  Done
• According to the Fourth (2017) National Climate Assessment (NCA) of the United States it is very likely sea level will rise between 30 and 130 cm (1.0 - 4.3 feet) in 2100 compared to the year 2000; and 2.4 m (8 feet) is physically possible but the authors were unable to say how likely. - could you elaborate a bit? Maybe split up the sentence too.  Done
• There is a widespread consensus that substantial long-term sea-level rise will continue for centuries to come even if the temperature stabilizes.[ - among who? Penguins? Polar bears? Conspiracy theorists?  Done
• It is thought that - by? If it's a consensus or a group of people, you should identify who holds this view, and by which research. It's probably based on something elsewhere in the article, if I had to guess.  Done
• Crossing such tipping points implies that ice-sheet changes are potentially irreversible - I don't like that "implies" for an encyclopedia article  Done
• For Greenland estimates roughly range between 1 and 4 °C - add comma and Fahrenheit  Done
• Melting of the Greenland ice sheet could contribute an additional 4 to 7.5 m (13 to 25 ft) over many thousands of years.[11] It has been estimated that we are committed to a sea-level rise of approximately 2.3 m (7 ft 7 in) for each degree of temperature rise within the next 2,000 years. - who says this? The "could" is vague, so is "It has been estimate that we..." - you should never refer to the reader in the article, or the collective "we".  Done
• Warming beyond the 2 °C target - Fahrenheit  Done

Regional sea level change

Subsidence, isostatic rebound, gravitational effects of changing ice masses, and spatially varying patterns of warming lead to differences in sea level change around the globe,[83] including regions with sea level fall (near current and former glaciers and ice sheets). - that is too much for one sentence. Warm up your readers with an introduction to the subject matter you're about to introduce, not throw in everything but the kitchen sink! If this entire section is about Greenland, then you should say as such, and put the last sentence of that paragraph first.  Done

• up to possibly 25 centimeters per year - inches?  Done
• So you go from smallest to largest for subsidence? When you say "up to possibly 25 cm", it should instead say the largest first - over 9 m (30 ft) in the Sacramento-San Joaquin River Delta.. Then you can say "Other regional examples include..."

Here the confusion lies in the difference between total and yearly subsidence.. I dropped the yearly examples (too many examples anyway). Femkemilene (talk) 13:25, 2 February 2019 (UTC)

Effects

• Current and future climate change - this article is about sea level rise, not climate change. I suppose you can question its semantics, but I think it should be switched  Done
• Many of these impacts are detrimental — especially for the three-quarters of the world's poor who depend on agriculture. - I have to ask, is this about climate change or sea level rise? Will the agrticulture of 3/4 of the world's poor be negatively affected by sea level rise? I'm guessing so because of River deltas in Africa and Asia and small island states are particularly vulnerable to sea-level rise. which you say later, but I'm confused by when you mention that. You also mention Asian countries being affected in the next paragraph.  Done It might be better to have the effects by areas in the same paragraph.

I do not have access to the source, but judging from the title (Climate shocks: Risk and vulnerability in an unequal world) and common sense, this is about climate change in general. I've struggled with the ordering of information in this section, but I think ordering per effect might be equally good/better than per location. We can't give an exhaustive summation of locations, but we can give a good overview of the types of effect locations might get. Femkemilene (talk) 17:34, 2 February 2019 (UTC)

• if following the current trajectory of 3°C. - Fahrenheit  Done
• This area can be huge as rights extend to a radius of 224 nautical miles (415 km; 258 mi) around the entire island state. - could you find a better way of saying it than "can be huge"?  Done

Adaptation

• About a quarter of the Netherlands lies beneath sea level, while more than 50% of the nation's area would be inundated by tidal floods if it did not have an extensive levee system. - source?  Done
• The New York City Panel on Climate Change (NPCC) is an effort to prepare the New York City area for climate change. - you didn't say anything about the NYC panel. The next sentence is about Miami  Done
• Options that have been proposed to assist island nations to adapt to rising sea level include abandoning islands, building dikes, and "building upwards." - none of this has been ascribed to anyone.  Done

Replaced that very old source with examples of adaptation that is actively considered or in place. Femkemilene (talk) 16:38, 2 February 2019 (UTC)

That's my review. There is a lot here, but a lot of it is number formatting. It could be doable within a week. I'll leave it open until February 2, next Saturday. ♫ Hurricanehink (talk) 03:27, 27 January 2019 (UTC)

Ow wow, thanks for your thorough review. I hope I can finish on the 2nd, might need the 3rd as well. Femkemilene (talk) 09:14, 28 January 2019 (UTC)

No prob. If you're still working on the review, I'll just leave it on hold. I'll only fail it if no work was done after a week. ♫ Hurricanehink (talk) 15:40, 28 January 2019 (UTC)

I think I've now addressed all of your points. I think the article has significantly improved and I hope it is now ready to be a good article :). Thanks again for your very good review. Femkemilene (talk) 17:34, 2 February 2019 (UTC)

Thanks so much for addressing all of this! Great work on the article, I'm happy to pass the article now. ♫ Hurricanehink (talk) 17:51, 2 February 2019 (UTC)

Why remove the word sophisticated? And why use outdated source (IPCC 2013) here when IPCC 1.5 report also talks about these models, and how drastically they have changed? Femkemilene (talk) 13:53, 17 January 2019 (UTC)

What DIFF are we talking about, F? NewsAndEventsGuy (talk) 14:09, 17 January 2019 (UTC)

I came across this when reading the AR5 chapter, and extended the part because I found information missing, and the previous line, "Semi-empiral modelling relies on sophisticated statistical techniques", not really easy understandable. And I couldn't really find something in regards to "more sophisticated", when now looking at the PNAS ref, it states, "Their simpler nature makes them feasible for probabilistic assessments and makes their results easier to reproduce." If you think they are more sophisticated re-add it, though it would be nicer to have this per a source. prokaryotes (talk) 14:12, 17 January 2019 (UTC)

For future reference, how do I link to a diff? Femkemilene (talk) 14:23, 17 January 2019 (UTC)

See HELP:DIFF NewsAndEventsGuy (talk) 14:55, 17 January 2019 (UTC)

One of the reasons your previous edit is outdated, is that it states that SEM "use relationships between observed global mean sea level and global mean temperature". This is incorrect for the newest generation of SEMs. They use more sophisticated techniques, specifically they now don't only regard GMSL but also the different contributions and time lagging. This can be found in the new 1.5 report. Could you correct your edit yourself? Femkemilene (talk) 14:31, 17 January 2019 (UTC)

And while you're at it, could you also make sure that the referencing is not duplicated. That chapter of IPCC was used a few times before. Femkemilene (talk) 14:32, 17 January 2019 (UTC)

The diff [2] in question. Femkemilene (talk) 15:00, 17 January 2019 (UTC)

This is not how Wikipedia works, only because something is outdated doesn't make it incorrect per se. My edit provided additional information in an effort to improve the article, it is not wrong. If you want to add the newest extended SEM definition simply hit that article edit button. i did not read the IPCC 1.5 report yet, and I have currently no time to begin looking into this, maybe later, maybe not. prokaryotes (talk) 15:17, 17 January 2019 (UTC)

If you don't have time to properly look for a description that is still accurate, you should not be editing Wikipedia now. Of course, a source from 2013 could still be accurate, but you should really check if that is the case. I'm not here to correct all of your edits. Femkemilene (talk) 15:21, 17 January 2019 (UTC)

Usually you would either edit the part we discuss here, or you would add a line with ..."since 2018, semiempirical models also use ...", again it is not wrong. Your previous edit was poorly written, it added something per your own synthesis, without providing a source, mentioning sophisticated, the part was also too technical. prokaryotes (talk) 15:31, 17 January 2019 (UTC)

If you see something that is poorly written, but don't have time to properly correct it, you could instead point towards it on the talk page. I will acknowledge and correct mistakes. Additions such as " Since 2018, we now have a different definition" are often clutter. We should give the current definition and only mention historical definition when sources describe the changes between definitions as significant. I think the word sophisticated popped up in personal communication with the lead author. I sent him an email to assess whether the findings were sufficiently supported by a wider research community to warrant inclusion in Wikipedia. It is fair that that word sophisticated is dropped, as it is not often used to describe their techniques. Femkemilene (talk) 15:51, 17 January 2019 (UTC)

i don't have a strong opinion how we frame this here, but I personally find it also informative to read about progress. Bottom line, in regards to ice sheet dynamics models still seem to perform poorly in relation to rapid periods of sea level rise in Earth's past, at least that's what I get from current researchers. Which then brings us back to linear projections such as from Hansen et al, and those larger estimates, which imho could also be pointed out when discussing modelling. prokaryotes (talk) 15:59, 17 January 2019 (UTC)

That is the reason SEMs should be included the model section. The post 2013 SEMs perform better in modelling rapid periods of sea level rise than most physical models. (Again, Hansen only referred to projection 1978, it was not him that made the projection. It was a projection based on MISI, so per definition not linear.) I might make a reference to such analytical models in the model section if I can find current sources for them. Femkemilene (talk) 16:09, 17 January 2019 (UTC)

I was referring to Hansen et al 2016 "Church et al. (2013) increased estimates of sea level rise compared to prior IPCC reports, but scenarios they discuss are close to linear responses to the assumed rising climate forcing. The most extreme climate forcing (RCP8.5, 936 ppm CO2 in 2100 and GHG forcing 8.5 W m−2 ) is estimated to produce 0.74 m sea level rise in 2100 relative to the 1986–2005 mean sea level, with the “likely” range of uncertainty at 0.52–0.98 m. Church et al. (2013) also discuss semi-empirical estimates of sea level rise, which yield ∼ 0.7–1.5 m for the RCP8.5 scenario, but express low confidence in the latter, thus giving preference to the model-based estimate of 0.52–0.98 m. We note that Sect. 4.4.4.2 on ice sheet processes in the IPCC chapter on cryosphere observations (Vaughan et al., 2013) contains valuable discussion of nonlinear ice sheet processes that could accelerate ice sheet mass loss but which are not fully included in current ice sheet models. AND The fundamental question we raise is whether ice sheet melt in response to rapid global warming will be nonlinear and better characterized by a doubling time for its rate of change or whether more linear processes dominate. Hansen (2005, 2007) argued on heuristic grounds that ice sheet disintegration is likely to be nonlinear if climate forcings continue to grow, and that sea level rise of several meters is possible on a timescale of the order of a century. Given current ice sheet melt rates, a 20-year doubling rate produces multi-meter sea level rise in a century, while 10- and 40-year doubling times require about 50 and 200 years, respectively" https://www.atmos-chem-phys.net/16/3761/2016/acp-16-3761-2016.pdf prokaryotes (talk) 17:28, 17 January 2019 (UTC)

I looked now at your suggestion for IPCC 1.5, but there is nothing on semi... https://www.ipcc.ch/site/assets/uploads/sites/2/2018/07/SR15_SPM_High_Res.pdf prokaryotes (talk) 17:31, 17 January 2019 (UTC)

What is your opinion about mentioning this here in regards to SEM, "Empirical analyses are needed if we doubt the realism of ice sheet models, but semi-empirical analyses lumping multiple processes together may yield a result that is too linear." also from Hansen 2016, has this changed? prokaryotes (talk) 17:49, 17 January 2019 (UTC)

Whatever happened to comprehensible WP:NOTJOURNAL secondary sources? NewsAndEventsGuy (talk) 19:42, 17 January 2019 (UTC)

I got carried away a bit too much in the details. @Prokaryotes: look in the chapter on physical changes instead of SPM. Newer SEMs lump less processes together and often produce less linear results than complex climate models. I'll tweak the text a bit, but I think NEAG is right in saying this is too technical for Wikipedia to devote a lot of space on. Femkemilene (talk) 09:33, 18 January 2019 (UTC)

Thanks, F! College undergrads will be regular readers here, so we should write for kids 14-18 years old per WP:ONEDOWN. NewsAndEventsGuy (talk) 10:29, 18 January 2019 (UTC)

Not entirely convinced by the sources provided in that article (multiple old interviews with respected scientist, no systematic analysis). I do remember there is a more systematic analysis about IPCC in general out there, not sure whether it mentions SLR, but will look into it. Femkemilene (talk) 20:36, 20 January 2019 (UTC)