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This article needs to be cited. It contradicts some things here. Zero talk 04:18, 17 January 2015 (UTC)
consistent with prior estimates from tide gauge records", but showing that the "
increase in rate relative to the 1901–90 trend is accordingly larger than previously thought; this revision may affect some projections of future sea-level rise." I see no contradiction, only a refinement and confirmation of the general trend already identified. ~ J. Johnson (JJ) ( talk) 22:26, 24 March 2015 (UTC)
I'm not sure, but I believe I once heard that a lowering of the groundwater also lowers the soil itself, in relation to the sea. This would be mainly because soild with water expands, and dried out soil reduces in size. In addition to this, water is also piped to the sea, which hence becomes a little bit higher (well, the effect of the latter is almost negligable, but perhaps still worth mentioning).
See Sewerage#Effect_of_sewerage_systems_on_water_table
Perhaps that we should mention this in the article, it seems very important to mention it to me. 2A02:A03F:1264:8900:213:20FF:FE3B:A79E ( talk) 13:49, 11 February 2015 (UTC)
This is true. It is called land subsidence. It has happened in big cities in California. There are many reports about it. Some big cities are now 15 to 20 feet lower because too much water was pumped from the ground. In some areas, levees were built to prevent the ocean from flooding the land. e.g. Alviso, California, which is near San Jose, CA. written August 11 ,2015 — Preceding unsigned comment added by 75.37.43.215 ( talk) 12:54, 11 August 2015 (UTC)
Is there a newer version of the graph at the start of the article? MissPiggysBoyfriend ( talk) 21:05, 10 June 2015 (UTC)
As far as I can see, the article makes no mention that the annual sea level rise of ~3mm per year is only 0.1% of the typical tidal range of 3m. Thus, it would take a thousand years for the effects on sea level of postulated climate change to equal those of standard twice-daily tides. Since seawalls have to be built considerably higher than the typical tide range to accommodate spring tides and storm surges, it follows that no flooding is likely due to this very small annual rise for a very long time.
Since the surface measurements seem to originate mostly from tide gauges this also raises the question of whether the resolution of these instruments is sufficient to detect so small a percentage change. In view of the difficult nature of the measurement being made, I would be very surprised if it were that high. More likely, a few percent. However, if the accuracy is less than 0.05% -a phenomenal achievement for any mechanical gauge- then the claimed figure of ~1.7mm annual sea level rise is meaningless. (Tide data source, UK Admiralty)-- Anteaus ( talk) 08:25, 15 August 2015 (UTC)
Note that List of cities impacted by current sea level rise has been proposed for deletion, as an inadequate treatment of an unfeasibly large list. This would be an opportunity to revise the section here on the Sea level rise#Effects of sea-level rise, particularly in regard of cities. ~ J. Johnson (JJ) ( talk) 18:15, 19 August 2015 (UTC)
The list has been deleted, as well as the link to it. The section needs re-writing (still looks like several factoids standing at a bus stop) but I'm feeling under-motivated. It's been a while since I looked, but I vaguely recall that one of the IPCC ARs had some material that would be useful here. ~ J. Johnson (JJ) ( talk) 21:59, 28 August 2015 (UTC)
even these modest effects currently cost $6 billion ...." The $1 trillion looks low: I see one forecast of $3.5 trillion by 2070 just for Miami (and also Guangzhou, China), with $2 trillion for New York-Newark. There are, indeed, plenty of good secondary sources (e.g.: the IPCC ARs, much of the NASA stuff, etc.). I think the article would be improved if we tapped those directly rather than filtered through the newspapers, which tend to have a parochial viewpoint. ~ J. Johnson (JJ) ( talk) 20:54, 31 August 2015 (UTC)
Cripes, I'm getting sucked into the whirlpool. Even after your edits I think the whole "Effects" section still needs to be torn out and rewritten: it's poorly organized, it lacks focus, there is no coherent concept as to what is being communicated. I particularly question the bit about "modest increases ... are likely to be offset when cities adapt" as not quite sensible. (They are not offsetting SLR, they're only trying to cope with it.) Anyway, I'm going to run up a draft (below).
I have also just inserted a new section ("Subsidence"), between "Contributions" and "Effects", as it makes a signficant contribution to effective sea level rise and the ensuing consequences. ~ J. Johnson (JJ) ( talk) 00:04, 2 September 2015 (UTC)
Draft for "Effects" section.
Actual sea level rise to-date has been modest (only xxxx inches citation needed), and the impacts to low-lying coastal cities have been modest. For example, in Miami (Florida) it is reported that certain streets flood at high tide about 10 times a year citation needed, while at Norfolk (Virginia), a few residential streets have been raised. citation needed Yet the cost of effective sea level rise (combined with subsidence) has already (xxxx) reached an estimated xxxxx per year citation needed, due to increased flooding from infrequent storms (as seen with Hurricane Katrina (2005), Hurricane Ike (2008), Cyclone Xynthia (2010), and Hurricane Sandy (2012)) and the cost of defense projects such as the Thames Barrier [( London) and MOSE Project ( Venice). A 2011 study [1] estimated that in 2005 about 40 million people and an estimated US$3,000 billion of assets (about 5% of global GDP) were exposed to a 1 in 100 year coastal flood event.
As sea level rises (in conjunction with subsidence and storm enhancement [2] very substantial economic assets will be subjected to flooding. This will apply especially to ports (as of 2015 13 of the 20 most populous cities in the world are ports [3]), but all cities, as well as broad regions and nations, dependent on those ports will be affected. It has been estimated that by the 2070s exposed assess will exceed US$3 trillion for Miami (USA) and Guangzhou (China), over $2 trillion for New York-Newark, and over $1 trillion for eight other urban agglomerations, including Calcutta, Shanghai, Mumbai, Tokyo, Hong Kong, and New Orleans.
References
- ^ Hanson et al. 2011, p. 89
- ^ Independently of sea level rise, global warming is expected to increase the intensity of storms. Hanson et al. 2011, p. 94
- ^ Hanson et al. 2011, p. 90
- Hanson, S.; Nicholls, R.; Ranger, N.; Hallegatte, S.; Corfee-Morlot, J.; Herweijer, C.; Chateau, J. (2011), "A global ranking of port cities with high exposure to climate extremes", Climatic Change, 104 (1): 89–111, doi: 10.1007/s10584-010-9977-4
Please only use referenced content, for instance Miami has a new pump system, some areas flood less atm. Also i prefer storm surge, instead of storm enhancements. The draft does not mention food growing regions in river deltas, or other low lying areas. If you add something, or rewrite something, take care not to remove referenced content, unless it becomes redundant or is out dated. Also references belong at the end of a sentence. Thanks. prokaryotes ( talk) 20:39, 2 September 2015 (UTC)
references belong at the end of a sentence." That is a stylistic preference, which has strong disadvantage of separating citations from the specific material they support, with consequent confusion. (It doesn't help that I left out one citation, so that sentence has only two citations for three facts. Sigh.) But do it however you want, I don't really care. ~ J. Johnson (JJ) ( talk) 22:13, 3 September 2015 (UTC)
Re the Subsidence section: it is not an effect of sea level rise, and its current location is therefore misleading. While it does not actually contribute to true sea level rise, it is an important contribution to local effective (or apparent) sea level rise. Which is why I put it immediately following the contributions section. (Though I don't think it would be too much of a stretch to put it at the end of "Contributions".) ~ J. Johnson (JJ) ( talk) 18:26, 2 September 2015 (UTC)
I did not see any thing on what will happen to change the Equatorial Bulge and tides with extra water in the oceans. Why not? 98.95.209.243 ( talk) 15:59, 6 September 2015 (UTC)
Could we please have some graphs in centimetres please? Most of the world has no idea what an inch actually represents, and this is an international topic on an international encyclopedia. Anyway, it's a scientific topic. Thanks for your work. 202.154.144.174 ( talk) 22:18, 5 November 2015 (UTC)
Hi all,
I have the source of the referenced document [75] here, and noticed the quoting of the text is not quite correct. The changes are minimal, but important enough. Lets not suggest something that was not said. The numbers quoted are the extremes in the specific area and not some sort of average or general occurrence. The original text also gives a timespan, for example for Rhine Delta. That was also missing from the quoted text. I tried to edit the article section myself, but it seems the changes are gone now. I dont know why that is.
Here is the corrected text for anyone who likes to put it in there again (additions between * *): "Total anthropogenic-caused subsidence in the Rhine-Meuse-Scheldt delta (Netherlands) is estimated at 3 to 4 meters *since the Middle Ages*, over nine meters in *some parts of* the Sacramento-San Joaquin River Delta, and over ten feet in *some* urban areas of the Mississippi River Delta (New Orleans).[75]"
Richard — Preceding unsigned comment added by 2001:983:3BAF:1:8989:32A7:D2D3:5512 ( talk) 23:31, 22 November 2015 (UTC)
Not sure what you mean here. The parts are quoted literally from the text but some things left out. It doesnt represent (paraphrase?) what that report is about either. We here in the Netherlands know all about subsidence and sea-levels, and we are not a sort of New-Atlantis. :) Same goes for the other areas mentioned. My edits were reverted and as I said I don't know why. I have no account here so maybe that has something to do with it. I wont try again, but its a bit funny. Richard — Preceding unsigned comment added by 2001:983:3BAF:1:C40F:32AE:EDEE:99A9 ( talk) 17:08, 4 December 2015 (UTC)
Nothing in this article mensions that the Sea level rise is more than compensated by the natural land rising by Post-glacial rebound in Northern Europe like Sweden and Canada. The Post-glacial rebound in Stockholm is 5 mm a year (5 meters in 1000 years) and some aeas in Northern Sweden it is up to 9 mm a year. This is more than most real bad predictions of sea level rise.
Also it gives much better proportions to this sea level rise article to mension that the Sea level rise is only a factor in other parts of the globe. It also gives a perspective of the natural phenomenia of changing coast lines. -- Zzalpha ( talk) 08:08, 5 December 2015 (UTC)
Zzalpa is righ IMHO to put the article in perspective. This is not about "ignoring" (whatever that may mean in a factual article..., this is not something political after all... ), it is just explaining what it is. You agreed that the "subsidence" section was useful, so why complain about the "negative" subsidence? I dont understand your reasoning. Richard — Preceding unsigned comment added by 2001:983:3BAF:1:C9F7:BE8D:FB2E:1E1D ( talk) 16:18, 7 December 2015 (UTC)
Sea level rise is more than compensated by the natural land rising by Post-glacial rebound...", and that "
[n]othing in this article mensions that". Unfortunately his statement is unclear, but perhaps he means that in Sweden and Canada post-glacial rebound exceeds expected SLR. (He provides no sources, but it seems plausible.) Even if, for the sake of argument, this be taken as true, so what? Does it mean, as I said before, that Swedes and Canadians can ignore SLR? (And as I also said before: not likely.) At the best it might explain ("provide perspective") why a Swede making a best-effort to measure SLR in her local fjord might not see it. But (and also as I said before) this is just a local condition, and it is beyond the scope of this article to mention all the local conditions all around the globe.
put the article in perspective", what we have here is nothing more than WP:SOAP-boxing. ~ J. Johnson (JJ) ( talk) 23:41, 11 January 2016 (UTC)
I have read that southern England is sinking and northern England is rising - rebound or tectonic? The US is rising quite rapidly in the middle and sinking on the coasts - same reason? This will probably continue until the next ice age no matter what the temperature is. 2601:181:8301:4510:1D1D:E05C:66CC:8EE8 ( talk) 12:09, 11 April 2018 (UTC)
As part of a University course at Rice University I would like to add to the Island Nations section of the Sea Level Rise wikipedia article. I will expand the given examples of island nations threatened by sea level rise with the addition of the Marshall Islands. Also, I would like to connect the scientific aspects of this section to human capabilities by analyzing how rising sea levels are affecting and changing traditional life styles. This would entail describing efforts in the Maldives, the Marshall Islands, and elsewhere to adapt to rising sea levels. I would greatly appreciate any suggestions about what should or should not be included and used for these articles. OLucier ( talk) 01:52, 12 February 2016 (UTC)
This article is yet another causality in wikipedia's climate wars. Let's start with the very first line which is the estimate of current sea level rise. The Tidal Gauge measurements say it is much less than this article puts at the low estimate range. "Absolute global sea level rise is believed to be 1.7-1.8 millimeters/year.” http://tidesandcurrents.noaa.gov/sltrends/globalregional.htm Next, The claim that sea level rise has accelerated in recent years is not agreed upon at all even by the IPCC which instead says that "No significant acceleration in the rate of sea level rise during the 20th century has been detected." https://www.ipcc.ch/ipccreports/tar/wg1/409.htm
Get all of this man made catastrophic global warming theory stuff out of the lead and into its own section 24.217.75.105 ( talk) 16:39, 30 April 2016 (UTC)
Major re-write needed. Even the most basic things that should be part of this article like the tidal gauge measurements are not here because of some political agenda. Put all of that stuff in it's own section. The global warming advocacy here is not helpful and is a major problem at wikipedia. This is an encyclopedia not a political soapbox— Preceding unsigned comment added by 24.217.75.105 ( talk) 14:41, 3 May 2016 (UTC)
The article says that because the Aurora subglacial basin lies kilometres below sea level, "seawater could penetrate beneath the ice, causing portions of the ice sheet to collapse and float off to sea." It is true that the referenced source says this, but it seems totally illogical. The ice there is very thick, which means that the pressure at the bottom of the ice is very high – too high to allow seawater to penetrate under it. Seawater will not be able to penetrate there unless and until the ice above melts or flows away sufficiently to decrease the thickness significantly. Only then could it become a floating ice shelf and have seawater below it. Eric Kvaalen ( talk) 08:26, 12 May 2016 (UTC)
WMC is correct. You and the article refer to the depth of the ice or the depth of the seawater- that's inadequate.. You need to adduce extra information concerning the height of the ice above sea level at the point/linearea in question, otherwise your point fails.
Gravuritas ( talk) 16:23, 24 May 2016 (UTC)
seems totally illogical" to you is entirely a problem of your personal understanding. What you seem to have missed is: 1) at the bottom of the ice-water contact the pressure of the water is also very high, and 2) ice floats. Well, it floats if it can sink deep enough to displace approximately the same volume of water, the latter being about 10% heavier for equal volumes. The situation you may have in mind is where the ice is resting on the bottom (more or less), so that it can't sink, and there is sufficient ice on top (above sea level) to provide more pressure than exerted by the water. Got it?
Eric, it seems there are quite a few things here that you don't understand, including the significance of transitioning from discussion of a point you don't understand to arguing about why you're right and who said what. As to the latter I have extracted the following time-line from the article and talk page histories, with the edit summaries.
Several itty-bitty details you have wrong. First, William did not "revert ... without responding". He respond to you on the 12th. I removed the tag on the 18th, you retagged on the 23rd, William removed it, you retagged on the 24th, William removed it again, you retagged (missing WP:3RR by three hours), and I removed it. Second, William did not accuse you of edit-warring, I did.
Some other points you don't understand: 1) Discussions are not resolved by whoever gets in the last word. 2) Having attracted everyone's notice with a tag, you don't get to keep adding it just because you don't like the way the discussion has gone. 3) Any interest in aiding your understanding of "seawater penetration" (or of what I think might be a real problem with the Science Daily source) is rapidly melting away in the face of your bickering. Which means you are less likely to get any discussion, but don't forget point #1. ~ J. Johnson (JJ) ( talk) 20:16, 25 May 2016 (UTC)
IF the statement is wrong...": I HAVE ALREADY ADDRESSED IT: "
Consider: Just how do you know this statement is false?" (20:30, 25 May). You are asking how to proceed on a very dubious assumption of falsity. As an experienced editor this should not have to be explained to you. ~ J. Johnson (JJ) ( talk) 21:39, 26 May 2016 (UTC)
discussed enough" is NOT dependent on your satisfaction, but on consensus. You don't understand something? You tagged, four of us have tried to explain it to you, and though you adamantly resist understanding the matter it appears there is consensus that the question regarding the text is settled. (Distinguished from the question in your mind, which isn't really applicable here.) If you don't agree, feel free to ask for a show of hands.
@ William M. Connolley, LeadSongDog, Gravuritas, and J. Johnson: The reason I am asking this question is because I would like to have your agreement that if we all see that something is wrong, then it should either be removed or marked "Dubious", even if there is a reference. The idea of "verifiability, not truth" means that things on Wikipedia must be verifiable, not just true. It does not mean that we can put things that are false just because we can find a reference that says that thing. A falsehood cannot be verified, it can only be referenced. A reference is not verification if the statement is false. I would like to move on to discussing the case in point, but I would like to know that you agree that if I convince you that the statement is false, or very likely false, we should do something about it and not just leave it as it is. Eric Kvaalen ( talk) 16:01, 31 May 2016 (UTC)
But JJ, taking something out of an article is not the same as including original research. Neither is it original research to mark something as dubious. When one marks something as dubious, one is supposed to start a discussion on the talk page about why it's dubious (see Template:Dubious). Then people are meant to discuss whether or not it's dubious. So far there has been very little discussion about that. Originally I said it was dubious, since no one had checked whether the elevation of the top of the ice was low enough for the ice to float. Later I checked that, so now I know that it's not just dubious, it's false. I can easily convince you of that, but you and the others seem to maintain that even if we're all sure that a statement is false, we do not have the right to question it or take it out if there is a reference. It reminds me of the story of the emperor's new clothes. We all know a statement is false, but no one dares to say so. Eric Kvaalen ( talk) 06:33, 5 June 2016 (UTC)
This isn't quite as outrageous as you might like us to think. Let's step through it one step at a time:
Are there false statements in reliable sources? The answer is yes, obviously, and the number is more likely to be measured in billions the millions.
Are there false statements in Wikipedia which are referenced to a reliable source?? The answer, again is yes.
What should be done if a false statement is found in Wikipedia which has a reference to a reliable source?
The short answer is it depends. The longer answer depends on the specific situation but some generalities can be discussed.
In the simplest situation, the statement is false and Wikipedia because the editor misread the reference. The solution here is simple—correct the sentence in Wikipedia.
In another simple situation the statement in Wikipedia accurately reflects the source, but the source has issued a subsequent correction. Again, the solution is simple and straightforward, after one fiuds the correction.
In a more complicated situation, one source says X and other reliable sources say Y. Wikipedia has well-established protocols for dealing with this.
Ratcheting up the complication, we might have some sources saying X and some other sources saying Y, with no clear preponderance. Again, Wikipedia has well-established protocols for how to address this.
Next, we might consider a case where there are not dueling sources, but only a single source with an obvious mathematical error. It is well-established that simple math does not constitute original research and corrections can be made. (This situation is not example of simple math.)
Now we might consider a situation restatement appears to be false, but one needs to bring in some scientific knowledge even if basic to refute the claim. In these situations, we at venturing into original research if we use that to change the claim. Presumably, if it is an important point, some other reliable source at some time will publish a contrary view, and we can move it into one of the categories discussed above where protocols exist.
Absent that, we are outside what I think are well-established protocols. We might examine how important the statement is. There are false statements that don't get corrected because they are so unimportant. If this statement is important and no one has corrected it why is that? Perhaps it hasn't been time, and we have to wait, perhaps it isn't as important as we think, or perhaps it isn't false.
With all this text I haven't suggested exactly what should be done in this specific situation, but I couldn't let the the implication that leaving a false statement in Wikipedia is absurd on its face.-- S Philbrick (Talk) 17:07, 6 June 2016 (UTC)
Please answer yes or no." (Do you understand the nature of leading questions?) Note also that the argument you keep trying to force on us is invalid as it is based on two unproven premises. Which, in the current case, are highly unlikely. Meanwhile: is it "yes" or "no"? ~ J. Johnson (JJ) ( talk) 21:08, 6 June 2016 (UTC)
it seems totally illogical." Now if an expert, with many years of experience, says "hmmm, something here doesn't seem right", that would be a good sign to pause and take a look. However, Eric doesn't have that kind of expertise. He is running purely on some inner sense of dissatisfaction. He has talked of doing some kind of calculation, but it seems to me he totally fails to appreciate just what kind of calculation he would have to do in regard of the specific case of the Aurora basin. And in any event any calculation he did would not suffice to delete material, only to convince the rest of us that would be the right thing to. Which he hasn't.
I have access to the primary source. Contact me using the link at Email Paul H.. Unfortunately, I have a publication that I need to finish ASAP and do not have the time to read through paper and prepare comments at this time. Paul H. ( talk) 13:50, 7 June 2016 (UTC)
Is the disputed sentence only supported by the news article or also by the Nature article? I searched the Nature article for "penetrate" and didn't find anything relevant to us, but they may have used different wording -- Distelfinck ( talk) 17:51, 8 June 2016 (UTC)
In relation to this discussion, but not the Sea level rise article, is Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica. by A. P. Wright, D. A. Young, and many others, 2012 in the Journal of geophysican Research. vol. 117, F01033, doi:10.1029/2011JF002066. It presents solid arguments that an active hydrological system, including subglacial lakes, at the base of a warm based ice sheet filling the Aurora Subglacial Basin allows discharge from subglacial lakes near the Dome C ice divide to reach the coast. This papers provides evidence that despite the pressure of the ice sheet filling the basin, liquid water exists at its base. Although the water is flowing out to the sea, the subglacial meltwater system would provide subaqueous conduit along which melting of the ice sheet would occur with shrinkage of the ice sheet and warming of the sea water. Frankly, we are flogging a dead horse that it should be allow to rest in peace. This paper shows why I rely upon peer-reviewed papers, not anonymous editors of doubful and unknown expertise. Surely, there must be a Wikipedia procedure for ending a pointless discussion. Paul H. ( talk) 02:09, 11 June 2016 (UTC)
Magnificent! I also prefer the original sources, for the same reason.
As to discussion of the original point, let's have a show of hands as to whether we done, or not.
@ LeadSongDog and Paul H.: JJ seems to have gone back to saying the statement is not dubious, or that it is dubious but we don't have the right to say so! Those of us who think the statement is false do not have to prove that it is false in order for the Dubious tag to be justified. But let me address your points. First of all, LeadSongDog, the areas where we know that that grounding lines are retreating are, by definition, near the coast. As I have already said, the Aurora basin is far inland in East Antarctica, and (crucially) the elevation of the upper surface of the ice is much higher. I don't think the word "fjord" applies to the whole basin, but rather only to the parts that were sculpted by glacier movement. It is true that the depth is not constant, but in my calculation I used the maximum depth. At other points my argument is even stronger. I don't see what the "fluidity" of the ice has to do with it. We actually do know the melting point. For example, at Lake Vostok, the melting point is −3°C, at a similar pressure. But I don't see what that has to do with our question. I am not saying that there is no water down at the bottom of the Aurora basin. In fact I said that there may be water, but the " head" difference would push it toward the sea, rather than sea water flowing into the basin. Finally, I do not understand your question "If it were as simple as you think, would someone not have published an explanation for the measurements seen?" What measurements are you talking about?
Paul, the article you cite makes it clear (as you yourself say) that the flow is from the continent toward the sea, because that is the direction of the gradient of hydraulic potential ("head", to use the engineering term). I don't see why you say "despite the pressure of the ice sheet filling the basin" water exists at its base. The pressure makes it more likely for water to exist (by lowering the freezing point by 3°C) and because thicker ice means that the bottom is more insulated from the cold air above. I also don't know what you mean by "subaqueous conduit". The rate of melting is determined by the rate of geothermal heating minus the rate of conduction of heat through the ice to the surface (or convection by flowing water and ice). I don't see what that has to do with the question of whether seawater can penetrate below the ice of the Aurora Basin. And just to remind you (though I still maintain that false statements should not be put in Wikipedia), the statement in question is not from a peer-reviewed paper.
To get back to the point, there's no way that seawater can get into the Aurora Subglacial Basin, because the elevation of the upper surface of the ice is much too high. The statement in the article is false.
Eric Kvaalen ( talk) 13:41, 12 June 2016 (UTC)
Without any noticed posted here, a discussion, "Are we allowed to delete a referenced statement if we all agree that it is false?" has been opened at Wikipedia:Village pump (policy). Although I am tired of flogging this dead horse, there might be other people who might have appreciated a notification about a discussion related to this article. Paul H. ( talk) 15:21, 12 June 2016 (UTC)
The tidal gauge measurements, the most basic thing possible, say that the very first line in this article is wrong. http://tidesandcurrents.noaa.gov/sltrends/globalregional.htm This is the official consensus source for the tidal gauge measurements and it says that their measurement is lower than your low range estimate. This needs fixing as well as everything else in the article but we will just start with the first line and go from there.
Moving on to sentence #2 "Additionally, sea level rise has accelerated in recent years.[4] For the period between 1870 and 2004, global average sea levels are estimated to have risen a total of 195 millimetres (7.7 in), and 1.7 millimetres (0.067 in) ± 0.3 millimetres (0.012 in) per year, with a significant acceleration of sea-level rise of 0.013 millimetres (0.00051 in) ± 0.006 millimetres (0.00024 in) per year per year."
Now to sentence #3: "According to one study of measurements available from 1950 to 2009, these measurements show an average annual rise in sea level of 1.7 millimetres (0.067 in) ± 0.3 millimetres (0.012 in) per year during this period, with satellite data showing a rise of 3.3 millimetres (0.13 in) ± 0.4 millimetres (0.016 in) per year from 1993 to 2009.[5]" This is laughable "study". What they are doing is comparing completely different kinds of measurements and then claiming that difference shows change. There were no sat measurements in 1950, and the tidal gauge measurements which do go back to 1950 don't show an increase by 2009. This is just junk science and should be removed completely. — Preceding unsigned comment added by 97.91.188.153 ( talk) 16:18, 11 September 2016 (UTC)
The present article, starting with the lead section, is obscure and rambling. Wikipedia:Manual of Style/Lead section says that the lead should be clear and accessible and “should identify the topic, establish context, explain why the topic is notable, and summarize the most important points, including any prominent controversies” It should say what sea level rise is and what it is not. In addition, several references are old: IPPC Fifth Assessment Report (AR5, 2013-14) is good but earlier versions are probably not. Current citations are vital.
Now for an attempt at constructive input. How about something like this for the lead paragraph?
Your input and improvement is requested. Rlsheehan ( talk) 00:32, 26 January 2017 (UTC)
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It would be useful if there was an introductory paragraph that noted the distinction between "eustatic" versus "relative" sea level rise and these two types were differentiated where referred to in this article. Paul H. ( talk) 03:29, 26 January 2017 (UTC)
WP:DENY (see this). JudgeRM (talk to me) 04:51, 29 January 2017 (UTC) |
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The following discussion has been closed. Please do not modify it. |
The Taiwan animation is distracting and does not let the reader read the text with peace, please delete it. Дэеюп8 ( talk) 14:15, 28 January 2017 (UTC)
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The article says "Sea Level Rise...has accelerated in recent years." However, Dr. Judith Curry disagrees, based upon the chart published in the IPCC AR5 report:
There is no measurement that shows recent acceleration. Period. The tidal gauges are the only one that goes back very far and if you calculate them the same way all the way through they show no acceleration in the rate of sea level rise (Hence Antarctica gaining ice and the reduced rate of warming we have seen the last 20 years as opposed to the previous 20 period). There are people who claim otherwise, but they have no long term data set to prove it. It is entirely hypothetical — Preceding unsigned comment added by 2600:100A:B11D:E1C1:91FC:3AF7:F68A:D51E ( talk) 21:15, 3 March 2017 (UTC)
Per BRD, I reverted this edit.
The source is worth reading.
It is a 1965 report published by the White House covering some interesting aspects of many subjects and including an appendix on atmospheric carbon dioxide.
I can see value in including material based on this document. For example, the report presumably summarizes the state of climate science with respect to carbon dioxide in 1965. A number of factual statements are made. It might be useful to identify some that have stood up to the test of time and others that have not. Perhaps most have stood up well, or perhaps the last 50 years have materially improved our understanding.
The report also includes a number of projections, some for the year 2000 as well as some others. It might be useful to identify some projections where actual results have come close to projections and it might be useful to identify projections where the intervening time has demonstrated different results.
I think we might be justified in doing any of these things but that wasn't what was done in this edit. The writers of this report presumably wanted to give the readers some information about the importance of the Antarctic ice cap, and used a hypothetical scenario, assuming the ice cap would be melted in 1000 years to illustrate the impact on sea level rise. However, there is absolutely nothing in the report to suggest that the selection of 1000 years for the complete melting of the ice Is an actual projection based on solid science or even a plausible scenario. Pulling that quote out of the report and dropping it into this article leaves the impression that the scientific minds in 1965 wanted the reader to think that a sea level rise of 40 feet per century was a plausible number. While I am only speculating as to their intent, I am not speculating about the context of the report. It is most certainly not a projection — it is a hypothetical as is clearly indicated by the use of phrases such as "sometimes been suggested", "suppose that the pollward heat flux were increased", "supposing a change in the earth wide radiation balance", "if 1000 years were required".-- S Philbrick (Talk) 18:13, 21 May 2017 (UTC)
I suggest to add projections for sea level rise from this 1981 study:
Melting of the world's ice sheets is another possible effect of CO2 warming. If they melted entirely, sea level would rise - 70 m [..] Danger of rapid sea level rise is posed by the West Antarctic ice sheet, which, unlike the land-based Greenland and East Antarctic ice sheets, is grounded below sea level, making it vulnerable to rapid disintegration and melting in case of general warming. The summer temperature in its vicinity is about -5°C. If this temperature rises ~5°C, deglaciation could be rapid, requiring a century or less and causing a sea level rise of 5 to 6 m. If the West Antarctic ice sheet melts on such a time scale, it will temporarily overwhelm any sea level change due to growth or decay of land-based ice. A sea level rise of 5 m would flood 25 percent of Louisiana and Florida, 10 percent of New Jersey, and many other lowlands throughout the world. https://pubs.giss.nasa.gov/docs/1981/1981_Hansen_ha04600x.pdf https://pubs.giss.nasa.gov/abs/ha04600x.html
prokaryotes ( talk) 09:57, 22 May 2017 (UTC)
As a semantic point, when I see the Section "Projections" followed by subsections "20th century", "21st century", and "After 2100", it seemed obvious that these were projections about those periods. Consistent with that assumption, the discussion in "after 2100" is a discussion about what happens after 2100. Similarly, the entries in "21st century" are predominated by predictions about the 21st century. However, the subsection "20th century" is not a prediction about the 20th century but a prediction about the 21st century made in the 20th century. We are mixing apples and oranges.-- S Philbrick (Talk) 15:03, 23 May 2017 (UTC)
The word "predicted" in the recent addition:
Hansen et al 1981, published the study Climate impact of increasing atmospheric carbon dioxide, and predicted that anthropogenic carbon dioxide warming and its potential effects on climate in the 21st century could cause a sea level rise of 5 to 6 m, from melting of the West Antarctic ice-sheet alone. (emphasis added)
is too strong. Confusingly, Hansen uses the term prediction on occasion, but in context it is clear he is talking about predictions based upon scenarios, which might better be called projections or perhaps scenario-based projections. For example he specifically says "prediction of the climate effect of CO2 requires projections of the amount of atmospheric CO2…". Note he further goes on to identify variables that are specifically neglected which is perfectly acceptable in a scenario-based projection but cannot possibly be called a prediction.-- S Philbrick (Talk) 15:28, 23 May 2017 (UTC)
We also have to be careful about cherry picking. The very same article includes the statement: ...It is not certain whether CO2 warming will cause the ice sheets to shrink or grow. For example, if the ice warms but the air above the ice sheets remains below freezing, the effect could be increased snowfall, net ice sheet growth, and thus lowering of sea level".
In an article about sea level rise, why would we choose one scenario in which the sea level rise is significant and ignore the one in which the sea level rise is negative? While the author goes on to suggest that the West Antarctic ice sheet melting could overwhelm the effects generating a sea level decrease, that conclusion is contingent, if the West Antarctic ice sheet melts on such a timescale....
The author has made sure to cover himself — if the sea level rises in the 21st century he can point to his article "predicting" it, if the sea level drops in the 21st century can point to the same article "predicting" it. One option is to report this honestly and note that he mentions both projections, another possibility is that this isn't the best source to be summarizing.-- S Philbrick (Talk) 15:39, 23 May 2017 (UTC)
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...erosion, sedimentation and the accumulation of sediment in rivers, oceans and other bodies of water. That sedimentation eventually causes all "reservoirs" to become full of sediment displacing all the water. Its a known issue in almost ever man-made reservoir ever created. It also causes water depths to be reduced, increases sunlight heating of water and drives up water temperatures throughout the reservoir. It can't be ignored and its evident every time a port or river channel has to be dredged to keep it navigable. Yet there's absolutely no mention of it whatsoever as even a POSSIBLE cause or contributing factor in "sea level rise". But "subsidence" is, even though increasing sediment volume and depth in coastal and delta regions should offset the supposed "settling" of coastal areas into the bodies of water they border.
Where "subsidence" is a concern, its primarily due to dewatering of the soil when wells are drilled to provide drinking water or to lower water tables so basements and foundations don't flood. Of course it goes without saying that when you take water out of the soil, it dries, contracts and becomes compressed. Buildings and other structures don't or at least shouldn't sink when they're large and heavy enough to be heavier and more dense than the soil supporting them because they should have foundations built on pilings driven down to "bedrock". But that hasn't occurred in many major coastal cities with rapid development and lots of land created by "fill" And even "bedrock" can sink if it's supporting enough weight. Especially if IT'S dewatered and dries out and contracts.
Regardless, sedimentation USED TO BE AN IMPORTANT PART OF EARTH SCIENCES AS TAUGHT IN ANY U.S. ELEMENTARY SCHOOL SCIENCE CLASS. Which is understandable because it so obviously exists, its so visible and so easily understood. And how old is the "average person" when he or she discovers that throwing solid objects in a container of liquid pushes the "level" of the fluid up inside the container? But supposed "scientists" and Wikipedians allegedly interested in and devoted to "science" AND "building an encyclopedia" have never heard of it or are completely ignoring it?
Pathetic. — Preceding unsigned comment added by 68.234.100.139 ( talk) 21:00, 16 July 2017 (UTC)
It provides a misleading view of the most recent data. See the latest NASA graph here for years after 2014: https://climate.nasa.gov/vital-signs/sea-level/ — Preceding unsigned comment added by [[User:{{{1}}}|{{{1}}}]] ([[User talk:{{{1}}}#top|talk]] • [[Special:Contributions/{{{1}}}|contribs]])
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This article needs to be cited. It contradicts some things here. Zero talk 04:18, 17 January 2015 (UTC)
consistent with prior estimates from tide gauge records", but showing that the "
increase in rate relative to the 1901–90 trend is accordingly larger than previously thought; this revision may affect some projections of future sea-level rise." I see no contradiction, only a refinement and confirmation of the general trend already identified. ~ J. Johnson (JJ) ( talk) 22:26, 24 March 2015 (UTC)
I'm not sure, but I believe I once heard that a lowering of the groundwater also lowers the soil itself, in relation to the sea. This would be mainly because soild with water expands, and dried out soil reduces in size. In addition to this, water is also piped to the sea, which hence becomes a little bit higher (well, the effect of the latter is almost negligable, but perhaps still worth mentioning).
See Sewerage#Effect_of_sewerage_systems_on_water_table
Perhaps that we should mention this in the article, it seems very important to mention it to me. 2A02:A03F:1264:8900:213:20FF:FE3B:A79E ( talk) 13:49, 11 February 2015 (UTC)
This is true. It is called land subsidence. It has happened in big cities in California. There are many reports about it. Some big cities are now 15 to 20 feet lower because too much water was pumped from the ground. In some areas, levees were built to prevent the ocean from flooding the land. e.g. Alviso, California, which is near San Jose, CA. written August 11 ,2015 — Preceding unsigned comment added by 75.37.43.215 ( talk) 12:54, 11 August 2015 (UTC)
Is there a newer version of the graph at the start of the article? MissPiggysBoyfriend ( talk) 21:05, 10 June 2015 (UTC)
As far as I can see, the article makes no mention that the annual sea level rise of ~3mm per year is only 0.1% of the typical tidal range of 3m. Thus, it would take a thousand years for the effects on sea level of postulated climate change to equal those of standard twice-daily tides. Since seawalls have to be built considerably higher than the typical tide range to accommodate spring tides and storm surges, it follows that no flooding is likely due to this very small annual rise for a very long time.
Since the surface measurements seem to originate mostly from tide gauges this also raises the question of whether the resolution of these instruments is sufficient to detect so small a percentage change. In view of the difficult nature of the measurement being made, I would be very surprised if it were that high. More likely, a few percent. However, if the accuracy is less than 0.05% -a phenomenal achievement for any mechanical gauge- then the claimed figure of ~1.7mm annual sea level rise is meaningless. (Tide data source, UK Admiralty)-- Anteaus ( talk) 08:25, 15 August 2015 (UTC)
Note that List of cities impacted by current sea level rise has been proposed for deletion, as an inadequate treatment of an unfeasibly large list. This would be an opportunity to revise the section here on the Sea level rise#Effects of sea-level rise, particularly in regard of cities. ~ J. Johnson (JJ) ( talk) 18:15, 19 August 2015 (UTC)
The list has been deleted, as well as the link to it. The section needs re-writing (still looks like several factoids standing at a bus stop) but I'm feeling under-motivated. It's been a while since I looked, but I vaguely recall that one of the IPCC ARs had some material that would be useful here. ~ J. Johnson (JJ) ( talk) 21:59, 28 August 2015 (UTC)
even these modest effects currently cost $6 billion ...." The $1 trillion looks low: I see one forecast of $3.5 trillion by 2070 just for Miami (and also Guangzhou, China), with $2 trillion for New York-Newark. There are, indeed, plenty of good secondary sources (e.g.: the IPCC ARs, much of the NASA stuff, etc.). I think the article would be improved if we tapped those directly rather than filtered through the newspapers, which tend to have a parochial viewpoint. ~ J. Johnson (JJ) ( talk) 20:54, 31 August 2015 (UTC)
Cripes, I'm getting sucked into the whirlpool. Even after your edits I think the whole "Effects" section still needs to be torn out and rewritten: it's poorly organized, it lacks focus, there is no coherent concept as to what is being communicated. I particularly question the bit about "modest increases ... are likely to be offset when cities adapt" as not quite sensible. (They are not offsetting SLR, they're only trying to cope with it.) Anyway, I'm going to run up a draft (below).
I have also just inserted a new section ("Subsidence"), between "Contributions" and "Effects", as it makes a signficant contribution to effective sea level rise and the ensuing consequences. ~ J. Johnson (JJ) ( talk) 00:04, 2 September 2015 (UTC)
Draft for "Effects" section.
Actual sea level rise to-date has been modest (only xxxx inches citation needed), and the impacts to low-lying coastal cities have been modest. For example, in Miami (Florida) it is reported that certain streets flood at high tide about 10 times a year citation needed, while at Norfolk (Virginia), a few residential streets have been raised. citation needed Yet the cost of effective sea level rise (combined with subsidence) has already (xxxx) reached an estimated xxxxx per year citation needed, due to increased flooding from infrequent storms (as seen with Hurricane Katrina (2005), Hurricane Ike (2008), Cyclone Xynthia (2010), and Hurricane Sandy (2012)) and the cost of defense projects such as the Thames Barrier [( London) and MOSE Project ( Venice). A 2011 study [1] estimated that in 2005 about 40 million people and an estimated US$3,000 billion of assets (about 5% of global GDP) were exposed to a 1 in 100 year coastal flood event.
As sea level rises (in conjunction with subsidence and storm enhancement [2] very substantial economic assets will be subjected to flooding. This will apply especially to ports (as of 2015 13 of the 20 most populous cities in the world are ports [3]), but all cities, as well as broad regions and nations, dependent on those ports will be affected. It has been estimated that by the 2070s exposed assess will exceed US$3 trillion for Miami (USA) and Guangzhou (China), over $2 trillion for New York-Newark, and over $1 trillion for eight other urban agglomerations, including Calcutta, Shanghai, Mumbai, Tokyo, Hong Kong, and New Orleans.
References
- ^ Hanson et al. 2011, p. 89
- ^ Independently of sea level rise, global warming is expected to increase the intensity of storms. Hanson et al. 2011, p. 94
- ^ Hanson et al. 2011, p. 90
- Hanson, S.; Nicholls, R.; Ranger, N.; Hallegatte, S.; Corfee-Morlot, J.; Herweijer, C.; Chateau, J. (2011), "A global ranking of port cities with high exposure to climate extremes", Climatic Change, 104 (1): 89–111, doi: 10.1007/s10584-010-9977-4
Please only use referenced content, for instance Miami has a new pump system, some areas flood less atm. Also i prefer storm surge, instead of storm enhancements. The draft does not mention food growing regions in river deltas, or other low lying areas. If you add something, or rewrite something, take care not to remove referenced content, unless it becomes redundant or is out dated. Also references belong at the end of a sentence. Thanks. prokaryotes ( talk) 20:39, 2 September 2015 (UTC)
references belong at the end of a sentence." That is a stylistic preference, which has strong disadvantage of separating citations from the specific material they support, with consequent confusion. (It doesn't help that I left out one citation, so that sentence has only two citations for three facts. Sigh.) But do it however you want, I don't really care. ~ J. Johnson (JJ) ( talk) 22:13, 3 September 2015 (UTC)
Re the Subsidence section: it is not an effect of sea level rise, and its current location is therefore misleading. While it does not actually contribute to true sea level rise, it is an important contribution to local effective (or apparent) sea level rise. Which is why I put it immediately following the contributions section. (Though I don't think it would be too much of a stretch to put it at the end of "Contributions".) ~ J. Johnson (JJ) ( talk) 18:26, 2 September 2015 (UTC)
I did not see any thing on what will happen to change the Equatorial Bulge and tides with extra water in the oceans. Why not? 98.95.209.243 ( talk) 15:59, 6 September 2015 (UTC)
Could we please have some graphs in centimetres please? Most of the world has no idea what an inch actually represents, and this is an international topic on an international encyclopedia. Anyway, it's a scientific topic. Thanks for your work. 202.154.144.174 ( talk) 22:18, 5 November 2015 (UTC)
Hi all,
I have the source of the referenced document [75] here, and noticed the quoting of the text is not quite correct. The changes are minimal, but important enough. Lets not suggest something that was not said. The numbers quoted are the extremes in the specific area and not some sort of average or general occurrence. The original text also gives a timespan, for example for Rhine Delta. That was also missing from the quoted text. I tried to edit the article section myself, but it seems the changes are gone now. I dont know why that is.
Here is the corrected text for anyone who likes to put it in there again (additions between * *): "Total anthropogenic-caused subsidence in the Rhine-Meuse-Scheldt delta (Netherlands) is estimated at 3 to 4 meters *since the Middle Ages*, over nine meters in *some parts of* the Sacramento-San Joaquin River Delta, and over ten feet in *some* urban areas of the Mississippi River Delta (New Orleans).[75]"
Richard — Preceding unsigned comment added by 2001:983:3BAF:1:8989:32A7:D2D3:5512 ( talk) 23:31, 22 November 2015 (UTC)
Not sure what you mean here. The parts are quoted literally from the text but some things left out. It doesnt represent (paraphrase?) what that report is about either. We here in the Netherlands know all about subsidence and sea-levels, and we are not a sort of New-Atlantis. :) Same goes for the other areas mentioned. My edits were reverted and as I said I don't know why. I have no account here so maybe that has something to do with it. I wont try again, but its a bit funny. Richard — Preceding unsigned comment added by 2001:983:3BAF:1:C40F:32AE:EDEE:99A9 ( talk) 17:08, 4 December 2015 (UTC)
Nothing in this article mensions that the Sea level rise is more than compensated by the natural land rising by Post-glacial rebound in Northern Europe like Sweden and Canada. The Post-glacial rebound in Stockholm is 5 mm a year (5 meters in 1000 years) and some aeas in Northern Sweden it is up to 9 mm a year. This is more than most real bad predictions of sea level rise.
Also it gives much better proportions to this sea level rise article to mension that the Sea level rise is only a factor in other parts of the globe. It also gives a perspective of the natural phenomenia of changing coast lines. -- Zzalpha ( talk) 08:08, 5 December 2015 (UTC)
Zzalpa is righ IMHO to put the article in perspective. This is not about "ignoring" (whatever that may mean in a factual article..., this is not something political after all... ), it is just explaining what it is. You agreed that the "subsidence" section was useful, so why complain about the "negative" subsidence? I dont understand your reasoning. Richard — Preceding unsigned comment added by 2001:983:3BAF:1:C9F7:BE8D:FB2E:1E1D ( talk) 16:18, 7 December 2015 (UTC)
Sea level rise is more than compensated by the natural land rising by Post-glacial rebound...", and that "
[n]othing in this article mensions that". Unfortunately his statement is unclear, but perhaps he means that in Sweden and Canada post-glacial rebound exceeds expected SLR. (He provides no sources, but it seems plausible.) Even if, for the sake of argument, this be taken as true, so what? Does it mean, as I said before, that Swedes and Canadians can ignore SLR? (And as I also said before: not likely.) At the best it might explain ("provide perspective") why a Swede making a best-effort to measure SLR in her local fjord might not see it. But (and also as I said before) this is just a local condition, and it is beyond the scope of this article to mention all the local conditions all around the globe.
put the article in perspective", what we have here is nothing more than WP:SOAP-boxing. ~ J. Johnson (JJ) ( talk) 23:41, 11 January 2016 (UTC)
I have read that southern England is sinking and northern England is rising - rebound or tectonic? The US is rising quite rapidly in the middle and sinking on the coasts - same reason? This will probably continue until the next ice age no matter what the temperature is. 2601:181:8301:4510:1D1D:E05C:66CC:8EE8 ( talk) 12:09, 11 April 2018 (UTC)
As part of a University course at Rice University I would like to add to the Island Nations section of the Sea Level Rise wikipedia article. I will expand the given examples of island nations threatened by sea level rise with the addition of the Marshall Islands. Also, I would like to connect the scientific aspects of this section to human capabilities by analyzing how rising sea levels are affecting and changing traditional life styles. This would entail describing efforts in the Maldives, the Marshall Islands, and elsewhere to adapt to rising sea levels. I would greatly appreciate any suggestions about what should or should not be included and used for these articles. OLucier ( talk) 01:52, 12 February 2016 (UTC)
This article is yet another causality in wikipedia's climate wars. Let's start with the very first line which is the estimate of current sea level rise. The Tidal Gauge measurements say it is much less than this article puts at the low estimate range. "Absolute global sea level rise is believed to be 1.7-1.8 millimeters/year.” http://tidesandcurrents.noaa.gov/sltrends/globalregional.htm Next, The claim that sea level rise has accelerated in recent years is not agreed upon at all even by the IPCC which instead says that "No significant acceleration in the rate of sea level rise during the 20th century has been detected." https://www.ipcc.ch/ipccreports/tar/wg1/409.htm
Get all of this man made catastrophic global warming theory stuff out of the lead and into its own section 24.217.75.105 ( talk) 16:39, 30 April 2016 (UTC)
Major re-write needed. Even the most basic things that should be part of this article like the tidal gauge measurements are not here because of some political agenda. Put all of that stuff in it's own section. The global warming advocacy here is not helpful and is a major problem at wikipedia. This is an encyclopedia not a political soapbox— Preceding unsigned comment added by 24.217.75.105 ( talk) 14:41, 3 May 2016 (UTC)
The article says that because the Aurora subglacial basin lies kilometres below sea level, "seawater could penetrate beneath the ice, causing portions of the ice sheet to collapse and float off to sea." It is true that the referenced source says this, but it seems totally illogical. The ice there is very thick, which means that the pressure at the bottom of the ice is very high – too high to allow seawater to penetrate under it. Seawater will not be able to penetrate there unless and until the ice above melts or flows away sufficiently to decrease the thickness significantly. Only then could it become a floating ice shelf and have seawater below it. Eric Kvaalen ( talk) 08:26, 12 May 2016 (UTC)
WMC is correct. You and the article refer to the depth of the ice or the depth of the seawater- that's inadequate.. You need to adduce extra information concerning the height of the ice above sea level at the point/linearea in question, otherwise your point fails.
Gravuritas ( talk) 16:23, 24 May 2016 (UTC)
seems totally illogical" to you is entirely a problem of your personal understanding. What you seem to have missed is: 1) at the bottom of the ice-water contact the pressure of the water is also very high, and 2) ice floats. Well, it floats if it can sink deep enough to displace approximately the same volume of water, the latter being about 10% heavier for equal volumes. The situation you may have in mind is where the ice is resting on the bottom (more or less), so that it can't sink, and there is sufficient ice on top (above sea level) to provide more pressure than exerted by the water. Got it?
Eric, it seems there are quite a few things here that you don't understand, including the significance of transitioning from discussion of a point you don't understand to arguing about why you're right and who said what. As to the latter I have extracted the following time-line from the article and talk page histories, with the edit summaries.
Several itty-bitty details you have wrong. First, William did not "revert ... without responding". He respond to you on the 12th. I removed the tag on the 18th, you retagged on the 23rd, William removed it, you retagged on the 24th, William removed it again, you retagged (missing WP:3RR by three hours), and I removed it. Second, William did not accuse you of edit-warring, I did.
Some other points you don't understand: 1) Discussions are not resolved by whoever gets in the last word. 2) Having attracted everyone's notice with a tag, you don't get to keep adding it just because you don't like the way the discussion has gone. 3) Any interest in aiding your understanding of "seawater penetration" (or of what I think might be a real problem with the Science Daily source) is rapidly melting away in the face of your bickering. Which means you are less likely to get any discussion, but don't forget point #1. ~ J. Johnson (JJ) ( talk) 20:16, 25 May 2016 (UTC)
IF the statement is wrong...": I HAVE ALREADY ADDRESSED IT: "
Consider: Just how do you know this statement is false?" (20:30, 25 May). You are asking how to proceed on a very dubious assumption of falsity. As an experienced editor this should not have to be explained to you. ~ J. Johnson (JJ) ( talk) 21:39, 26 May 2016 (UTC)
discussed enough" is NOT dependent on your satisfaction, but on consensus. You don't understand something? You tagged, four of us have tried to explain it to you, and though you adamantly resist understanding the matter it appears there is consensus that the question regarding the text is settled. (Distinguished from the question in your mind, which isn't really applicable here.) If you don't agree, feel free to ask for a show of hands.
@ William M. Connolley, LeadSongDog, Gravuritas, and J. Johnson: The reason I am asking this question is because I would like to have your agreement that if we all see that something is wrong, then it should either be removed or marked "Dubious", even if there is a reference. The idea of "verifiability, not truth" means that things on Wikipedia must be verifiable, not just true. It does not mean that we can put things that are false just because we can find a reference that says that thing. A falsehood cannot be verified, it can only be referenced. A reference is not verification if the statement is false. I would like to move on to discussing the case in point, but I would like to know that you agree that if I convince you that the statement is false, or very likely false, we should do something about it and not just leave it as it is. Eric Kvaalen ( talk) 16:01, 31 May 2016 (UTC)
But JJ, taking something out of an article is not the same as including original research. Neither is it original research to mark something as dubious. When one marks something as dubious, one is supposed to start a discussion on the talk page about why it's dubious (see Template:Dubious). Then people are meant to discuss whether or not it's dubious. So far there has been very little discussion about that. Originally I said it was dubious, since no one had checked whether the elevation of the top of the ice was low enough for the ice to float. Later I checked that, so now I know that it's not just dubious, it's false. I can easily convince you of that, but you and the others seem to maintain that even if we're all sure that a statement is false, we do not have the right to question it or take it out if there is a reference. It reminds me of the story of the emperor's new clothes. We all know a statement is false, but no one dares to say so. Eric Kvaalen ( talk) 06:33, 5 June 2016 (UTC)
This isn't quite as outrageous as you might like us to think. Let's step through it one step at a time:
Are there false statements in reliable sources? The answer is yes, obviously, and the number is more likely to be measured in billions the millions.
Are there false statements in Wikipedia which are referenced to a reliable source?? The answer, again is yes.
What should be done if a false statement is found in Wikipedia which has a reference to a reliable source?
The short answer is it depends. The longer answer depends on the specific situation but some generalities can be discussed.
In the simplest situation, the statement is false and Wikipedia because the editor misread the reference. The solution here is simple—correct the sentence in Wikipedia.
In another simple situation the statement in Wikipedia accurately reflects the source, but the source has issued a subsequent correction. Again, the solution is simple and straightforward, after one fiuds the correction.
In a more complicated situation, one source says X and other reliable sources say Y. Wikipedia has well-established protocols for dealing with this.
Ratcheting up the complication, we might have some sources saying X and some other sources saying Y, with no clear preponderance. Again, Wikipedia has well-established protocols for how to address this.
Next, we might consider a case where there are not dueling sources, but only a single source with an obvious mathematical error. It is well-established that simple math does not constitute original research and corrections can be made. (This situation is not example of simple math.)
Now we might consider a situation restatement appears to be false, but one needs to bring in some scientific knowledge even if basic to refute the claim. In these situations, we at venturing into original research if we use that to change the claim. Presumably, if it is an important point, some other reliable source at some time will publish a contrary view, and we can move it into one of the categories discussed above where protocols exist.
Absent that, we are outside what I think are well-established protocols. We might examine how important the statement is. There are false statements that don't get corrected because they are so unimportant. If this statement is important and no one has corrected it why is that? Perhaps it hasn't been time, and we have to wait, perhaps it isn't as important as we think, or perhaps it isn't false.
With all this text I haven't suggested exactly what should be done in this specific situation, but I couldn't let the the implication that leaving a false statement in Wikipedia is absurd on its face.-- S Philbrick (Talk) 17:07, 6 June 2016 (UTC)
Please answer yes or no." (Do you understand the nature of leading questions?) Note also that the argument you keep trying to force on us is invalid as it is based on two unproven premises. Which, in the current case, are highly unlikely. Meanwhile: is it "yes" or "no"? ~ J. Johnson (JJ) ( talk) 21:08, 6 June 2016 (UTC)
it seems totally illogical." Now if an expert, with many years of experience, says "hmmm, something here doesn't seem right", that would be a good sign to pause and take a look. However, Eric doesn't have that kind of expertise. He is running purely on some inner sense of dissatisfaction. He has talked of doing some kind of calculation, but it seems to me he totally fails to appreciate just what kind of calculation he would have to do in regard of the specific case of the Aurora basin. And in any event any calculation he did would not suffice to delete material, only to convince the rest of us that would be the right thing to. Which he hasn't.
I have access to the primary source. Contact me using the link at Email Paul H.. Unfortunately, I have a publication that I need to finish ASAP and do not have the time to read through paper and prepare comments at this time. Paul H. ( talk) 13:50, 7 June 2016 (UTC)
Is the disputed sentence only supported by the news article or also by the Nature article? I searched the Nature article for "penetrate" and didn't find anything relevant to us, but they may have used different wording -- Distelfinck ( talk) 17:51, 8 June 2016 (UTC)
In relation to this discussion, but not the Sea level rise article, is Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica. by A. P. Wright, D. A. Young, and many others, 2012 in the Journal of geophysican Research. vol. 117, F01033, doi:10.1029/2011JF002066. It presents solid arguments that an active hydrological system, including subglacial lakes, at the base of a warm based ice sheet filling the Aurora Subglacial Basin allows discharge from subglacial lakes near the Dome C ice divide to reach the coast. This papers provides evidence that despite the pressure of the ice sheet filling the basin, liquid water exists at its base. Although the water is flowing out to the sea, the subglacial meltwater system would provide subaqueous conduit along which melting of the ice sheet would occur with shrinkage of the ice sheet and warming of the sea water. Frankly, we are flogging a dead horse that it should be allow to rest in peace. This paper shows why I rely upon peer-reviewed papers, not anonymous editors of doubful and unknown expertise. Surely, there must be a Wikipedia procedure for ending a pointless discussion. Paul H. ( talk) 02:09, 11 June 2016 (UTC)
Magnificent! I also prefer the original sources, for the same reason.
As to discussion of the original point, let's have a show of hands as to whether we done, or not.
@ LeadSongDog and Paul H.: JJ seems to have gone back to saying the statement is not dubious, or that it is dubious but we don't have the right to say so! Those of us who think the statement is false do not have to prove that it is false in order for the Dubious tag to be justified. But let me address your points. First of all, LeadSongDog, the areas where we know that that grounding lines are retreating are, by definition, near the coast. As I have already said, the Aurora basin is far inland in East Antarctica, and (crucially) the elevation of the upper surface of the ice is much higher. I don't think the word "fjord" applies to the whole basin, but rather only to the parts that were sculpted by glacier movement. It is true that the depth is not constant, but in my calculation I used the maximum depth. At other points my argument is even stronger. I don't see what the "fluidity" of the ice has to do with it. We actually do know the melting point. For example, at Lake Vostok, the melting point is −3°C, at a similar pressure. But I don't see what that has to do with our question. I am not saying that there is no water down at the bottom of the Aurora basin. In fact I said that there may be water, but the " head" difference would push it toward the sea, rather than sea water flowing into the basin. Finally, I do not understand your question "If it were as simple as you think, would someone not have published an explanation for the measurements seen?" What measurements are you talking about?
Paul, the article you cite makes it clear (as you yourself say) that the flow is from the continent toward the sea, because that is the direction of the gradient of hydraulic potential ("head", to use the engineering term). I don't see why you say "despite the pressure of the ice sheet filling the basin" water exists at its base. The pressure makes it more likely for water to exist (by lowering the freezing point by 3°C) and because thicker ice means that the bottom is more insulated from the cold air above. I also don't know what you mean by "subaqueous conduit". The rate of melting is determined by the rate of geothermal heating minus the rate of conduction of heat through the ice to the surface (or convection by flowing water and ice). I don't see what that has to do with the question of whether seawater can penetrate below the ice of the Aurora Basin. And just to remind you (though I still maintain that false statements should not be put in Wikipedia), the statement in question is not from a peer-reviewed paper.
To get back to the point, there's no way that seawater can get into the Aurora Subglacial Basin, because the elevation of the upper surface of the ice is much too high. The statement in the article is false.
Eric Kvaalen ( talk) 13:41, 12 June 2016 (UTC)
Without any noticed posted here, a discussion, "Are we allowed to delete a referenced statement if we all agree that it is false?" has been opened at Wikipedia:Village pump (policy). Although I am tired of flogging this dead horse, there might be other people who might have appreciated a notification about a discussion related to this article. Paul H. ( talk) 15:21, 12 June 2016 (UTC)
The tidal gauge measurements, the most basic thing possible, say that the very first line in this article is wrong. http://tidesandcurrents.noaa.gov/sltrends/globalregional.htm This is the official consensus source for the tidal gauge measurements and it says that their measurement is lower than your low range estimate. This needs fixing as well as everything else in the article but we will just start with the first line and go from there.
Moving on to sentence #2 "Additionally, sea level rise has accelerated in recent years.[4] For the period between 1870 and 2004, global average sea levels are estimated to have risen a total of 195 millimetres (7.7 in), and 1.7 millimetres (0.067 in) ± 0.3 millimetres (0.012 in) per year, with a significant acceleration of sea-level rise of 0.013 millimetres (0.00051 in) ± 0.006 millimetres (0.00024 in) per year per year."
Now to sentence #3: "According to one study of measurements available from 1950 to 2009, these measurements show an average annual rise in sea level of 1.7 millimetres (0.067 in) ± 0.3 millimetres (0.012 in) per year during this period, with satellite data showing a rise of 3.3 millimetres (0.13 in) ± 0.4 millimetres (0.016 in) per year from 1993 to 2009.[5]" This is laughable "study". What they are doing is comparing completely different kinds of measurements and then claiming that difference shows change. There were no sat measurements in 1950, and the tidal gauge measurements which do go back to 1950 don't show an increase by 2009. This is just junk science and should be removed completely. — Preceding unsigned comment added by 97.91.188.153 ( talk) 16:18, 11 September 2016 (UTC)
The present article, starting with the lead section, is obscure and rambling. Wikipedia:Manual of Style/Lead section says that the lead should be clear and accessible and “should identify the topic, establish context, explain why the topic is notable, and summarize the most important points, including any prominent controversies” It should say what sea level rise is and what it is not. In addition, several references are old: IPPC Fifth Assessment Report (AR5, 2013-14) is good but earlier versions are probably not. Current citations are vital.
Now for an attempt at constructive input. How about something like this for the lead paragraph?
Your input and improvement is requested. Rlsheehan ( talk) 00:32, 26 January 2017 (UTC)
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It would be useful if there was an introductory paragraph that noted the distinction between "eustatic" versus "relative" sea level rise and these two types were differentiated where referred to in this article. Paul H. ( talk) 03:29, 26 January 2017 (UTC)
WP:DENY (see this). JudgeRM (talk to me) 04:51, 29 January 2017 (UTC) |
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The following discussion has been closed. Please do not modify it. |
The Taiwan animation is distracting and does not let the reader read the text with peace, please delete it. Дэеюп8 ( talk) 14:15, 28 January 2017 (UTC)
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The article says "Sea Level Rise...has accelerated in recent years." However, Dr. Judith Curry disagrees, based upon the chart published in the IPCC AR5 report:
There is no measurement that shows recent acceleration. Period. The tidal gauges are the only one that goes back very far and if you calculate them the same way all the way through they show no acceleration in the rate of sea level rise (Hence Antarctica gaining ice and the reduced rate of warming we have seen the last 20 years as opposed to the previous 20 period). There are people who claim otherwise, but they have no long term data set to prove it. It is entirely hypothetical — Preceding unsigned comment added by 2600:100A:B11D:E1C1:91FC:3AF7:F68A:D51E ( talk) 21:15, 3 March 2017 (UTC)
Per BRD, I reverted this edit.
The source is worth reading.
It is a 1965 report published by the White House covering some interesting aspects of many subjects and including an appendix on atmospheric carbon dioxide.
I can see value in including material based on this document. For example, the report presumably summarizes the state of climate science with respect to carbon dioxide in 1965. A number of factual statements are made. It might be useful to identify some that have stood up to the test of time and others that have not. Perhaps most have stood up well, or perhaps the last 50 years have materially improved our understanding.
The report also includes a number of projections, some for the year 2000 as well as some others. It might be useful to identify some projections where actual results have come close to projections and it might be useful to identify projections where the intervening time has demonstrated different results.
I think we might be justified in doing any of these things but that wasn't what was done in this edit. The writers of this report presumably wanted to give the readers some information about the importance of the Antarctic ice cap, and used a hypothetical scenario, assuming the ice cap would be melted in 1000 years to illustrate the impact on sea level rise. However, there is absolutely nothing in the report to suggest that the selection of 1000 years for the complete melting of the ice Is an actual projection based on solid science or even a plausible scenario. Pulling that quote out of the report and dropping it into this article leaves the impression that the scientific minds in 1965 wanted the reader to think that a sea level rise of 40 feet per century was a plausible number. While I am only speculating as to their intent, I am not speculating about the context of the report. It is most certainly not a projection — it is a hypothetical as is clearly indicated by the use of phrases such as "sometimes been suggested", "suppose that the pollward heat flux were increased", "supposing a change in the earth wide radiation balance", "if 1000 years were required".-- S Philbrick (Talk) 18:13, 21 May 2017 (UTC)
I suggest to add projections for sea level rise from this 1981 study:
Melting of the world's ice sheets is another possible effect of CO2 warming. If they melted entirely, sea level would rise - 70 m [..] Danger of rapid sea level rise is posed by the West Antarctic ice sheet, which, unlike the land-based Greenland and East Antarctic ice sheets, is grounded below sea level, making it vulnerable to rapid disintegration and melting in case of general warming. The summer temperature in its vicinity is about -5°C. If this temperature rises ~5°C, deglaciation could be rapid, requiring a century or less and causing a sea level rise of 5 to 6 m. If the West Antarctic ice sheet melts on such a time scale, it will temporarily overwhelm any sea level change due to growth or decay of land-based ice. A sea level rise of 5 m would flood 25 percent of Louisiana and Florida, 10 percent of New Jersey, and many other lowlands throughout the world. https://pubs.giss.nasa.gov/docs/1981/1981_Hansen_ha04600x.pdf https://pubs.giss.nasa.gov/abs/ha04600x.html
prokaryotes ( talk) 09:57, 22 May 2017 (UTC)
As a semantic point, when I see the Section "Projections" followed by subsections "20th century", "21st century", and "After 2100", it seemed obvious that these were projections about those periods. Consistent with that assumption, the discussion in "after 2100" is a discussion about what happens after 2100. Similarly, the entries in "21st century" are predominated by predictions about the 21st century. However, the subsection "20th century" is not a prediction about the 20th century but a prediction about the 21st century made in the 20th century. We are mixing apples and oranges.-- S Philbrick (Talk) 15:03, 23 May 2017 (UTC)
The word "predicted" in the recent addition:
Hansen et al 1981, published the study Climate impact of increasing atmospheric carbon dioxide, and predicted that anthropogenic carbon dioxide warming and its potential effects on climate in the 21st century could cause a sea level rise of 5 to 6 m, from melting of the West Antarctic ice-sheet alone. (emphasis added)
is too strong. Confusingly, Hansen uses the term prediction on occasion, but in context it is clear he is talking about predictions based upon scenarios, which might better be called projections or perhaps scenario-based projections. For example he specifically says "prediction of the climate effect of CO2 requires projections of the amount of atmospheric CO2…". Note he further goes on to identify variables that are specifically neglected which is perfectly acceptable in a scenario-based projection but cannot possibly be called a prediction.-- S Philbrick (Talk) 15:28, 23 May 2017 (UTC)
We also have to be careful about cherry picking. The very same article includes the statement: ...It is not certain whether CO2 warming will cause the ice sheets to shrink or grow. For example, if the ice warms but the air above the ice sheets remains below freezing, the effect could be increased snowfall, net ice sheet growth, and thus lowering of sea level".
In an article about sea level rise, why would we choose one scenario in which the sea level rise is significant and ignore the one in which the sea level rise is negative? While the author goes on to suggest that the West Antarctic ice sheet melting could overwhelm the effects generating a sea level decrease, that conclusion is contingent, if the West Antarctic ice sheet melts on such a timescale....
The author has made sure to cover himself — if the sea level rises in the 21st century he can point to his article "predicting" it, if the sea level drops in the 21st century can point to the same article "predicting" it. One option is to report this honestly and note that he mentions both projections, another possibility is that this isn't the best source to be summarizing.-- S Philbrick (Talk) 15:39, 23 May 2017 (UTC)
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...erosion, sedimentation and the accumulation of sediment in rivers, oceans and other bodies of water. That sedimentation eventually causes all "reservoirs" to become full of sediment displacing all the water. Its a known issue in almost ever man-made reservoir ever created. It also causes water depths to be reduced, increases sunlight heating of water and drives up water temperatures throughout the reservoir. It can't be ignored and its evident every time a port or river channel has to be dredged to keep it navigable. Yet there's absolutely no mention of it whatsoever as even a POSSIBLE cause or contributing factor in "sea level rise". But "subsidence" is, even though increasing sediment volume and depth in coastal and delta regions should offset the supposed "settling" of coastal areas into the bodies of water they border.
Where "subsidence" is a concern, its primarily due to dewatering of the soil when wells are drilled to provide drinking water or to lower water tables so basements and foundations don't flood. Of course it goes without saying that when you take water out of the soil, it dries, contracts and becomes compressed. Buildings and other structures don't or at least shouldn't sink when they're large and heavy enough to be heavier and more dense than the soil supporting them because they should have foundations built on pilings driven down to "bedrock". But that hasn't occurred in many major coastal cities with rapid development and lots of land created by "fill" And even "bedrock" can sink if it's supporting enough weight. Especially if IT'S dewatered and dries out and contracts.
Regardless, sedimentation USED TO BE AN IMPORTANT PART OF EARTH SCIENCES AS TAUGHT IN ANY U.S. ELEMENTARY SCHOOL SCIENCE CLASS. Which is understandable because it so obviously exists, its so visible and so easily understood. And how old is the "average person" when he or she discovers that throwing solid objects in a container of liquid pushes the "level" of the fluid up inside the container? But supposed "scientists" and Wikipedians allegedly interested in and devoted to "science" AND "building an encyclopedia" have never heard of it or are completely ignoring it?
Pathetic. — Preceding unsigned comment added by 68.234.100.139 ( talk) 21:00, 16 July 2017 (UTC)
It provides a misleading view of the most recent data. See the latest NASA graph here for years after 2014: https://climate.nasa.gov/vital-signs/sea-level/ — Preceding unsigned comment added by [[User:{{{1}}}|{{{1}}}]] ([[User talk:{{{1}}}#top|talk]] • [[Special:Contributions/{{{1}}}|contribs]])