Talk:Greenland ice sheet

message: :* history and age of the ice sheet (110,000 year old ice vs. reports of millions of year old ice cap?)
:* fix exact percentage of Greenland's area covered by the ice cap (estimates range from 79 to 85%)
:* some nice images, preferably of ice melt, or mass balance (see for example )
:* adding a bit more on mass balance, precipitation, processes.
Jens Nielsen 18:57, 21 February 2006 (UTC)
replies: text: * Add information from here (greenland ice melt ~154 Gt/y) : http://www.ametsoc.org/atmospolicy/documents/ICE_GRACE_ams_briefing.pdf  —Preceding unsigned comment added by 213.216.199.26 (talk) 11:00, 27 April 2008 (UTC)
thread_title: To Do

message: "It was estimated that in the year 2007 Greenland ice sheet lost 592 km3 of its mass. [11]"
Actually the source says that greenland MELT during the SUMMER that amount. It also gained mass by snowfalls etc. According to the source, net lost was only 65 km3. However, I guess that only counts the melt/snowfall, but not icebergs etc.  —Preceding unsigned comment added by 213.216.199.26 (talk) 20:29, 21 April 2008 (UTC)
thread_title:  loosing mass = melting? in year 2007? 

message: *"If the ice would disappear, Greenland would most probably appear as an archipelago."
This is somehow misleading, without taking into account the Post-glacial rebound. The melting of such a mass of ice will certainly been followed by isostatic ajustment, like currently in Scandinavia. universimmedia 22:38, 27 June 2006 (UTC)
thread_title:  Post-melting archipelago ? 

message: * "According to the study, in 1996 Greenland was losing about 96 km3 per year in mass from its ice sheet."
I hope I'm not just being anal, but isn't it incorrect to say "in mass" there, since km3 is a measure of volume?
:~Murftown, 21 July 06
=== Time frame of the melting ? ===
I know scientists are very careful not to say anything about this, but what are the estimates of the time Greenland Ice Sheet takes to melt ?  1500 years (as in the end of the last ice age) - 150 years (as there's ~10 times less ice than in the last ice age)?   —Preceding unsigned comment added by 91.153.60.138 (talk) 07:23, August 26, 2007 (UTC) 
- Quick answer:  We don't know.  Between 50 and 1500 years..  —Preceding unsigned comment added by 87.86.252.131 (talk) 10:21, August 28, 2007 (UTC) 
Great example of scientific innumeracy from questioner and answerer. Time frame = amount of ice/loss rate = 3 million / 200 = 15,000 years roughly. Of course this calculation is not done in the article because the answer is not sufficiently alarming.  —Preceding unsigned comment added by 128.243.220.42 (talk) 15:04, 8 October 2007 (UTC)
replies: text: It's actually more complicated than that. There can be strongly non-linear effects, such as pools of water forming that absorb sunlight much more efficiently than ice, and liquid water build-up below the ice that carries large blocks out into the sea. But even without such effects the ice-loss rate is going to change significantly due to climate change. It could increase (due to higher temperatures) or decrease (due to increased precipitation at high altitude). The most pessimistic scenario in the IPCC graph shown in the article has most of the ice gone by the year 3000. (The graph shows a 600 cm sea level rise, and a 720 cm rise would correspond to all of the ice sheet.) --PeR 19:59, 9 October 2007 (UTC)

text: Side-effects of ponding were important with the Larsen Ice Shelf collapse. While that was over sea, the role of ponding is somewhat measured in the Greenland ice sheet -
*Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow Originally published in Science Express on 6 June 2002, Science 12 July 2002: Vol. 297. no. 5579, pp. 218 - 222 "The near coincidence of the ice acceleration with the duration of surface melting, followed by deceleration after the melting ceases... provides a mechanism for rapid, large-scale, dynamic responses of ice sheets to climate warming."
*Evolution of melt pond volume on the surface of the Greenland Ice Sheet GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L03501, "estimating the depth and hence volume of surface melt ponds... show large intra- and interannual changes in ponded water volumes, and large volumes of liquid water stored in extensive slush zones."
Then add the tracking of accumulated changes by ponding causing accelerated change in the ice sheet in the earthquake record ....
*Global warming yields 'glacial earthquakes' in polar areas "Glacial earthquakes in Greenland, the researchers found, are most common in July and August, and have more than doubled in number since 2002." - 
*Glacial earthquakes rock Greenland ice sheet 12:36 24 March 2006, NewScientist.com news service " quakes ranged from six to 15 per year from 1993 to 2002, then jumped to 20 in 2003, 23 in 2004, and 32 in the first 10 months of 2005."
Another dynamic of melting ice happens with such events as the Missoula Floods.--Smkolins (talk) 01:14, 12 January 2008 (UTC)
replies: text:  Allow the rate of increase in global warming increases at an increasing rate with periodic discordant surges as the tipping points tip, three earth atmospheres of methane get released, the sea ice melts affecting the albedo, human population doubles by the end of the century doubling the anthropogenic effects, eventually the result is the sixth global extinction event, but factor in also the SLR from West Antarctica and now the Totten glacier in East Antarctica. Add to that the shift from el Nino to La Nina acts to put more heat in the atmosphere than in the oceans where it has been being stored then model that either as doubling or the Fibonacci series and it gets interesting. Using the Rules of 72, 70, or 69 you just divide the rate into the rule to get the doubling time. With the rule of seventy and a rate of one percent the melting rate takes 70 years to double. Suppose the rate increases at an increasing rate as the Fibonacci series 1,1,2,3,5,8... much like what we observe with temperature and sea level rise, we might see Greenland melt in a couple of centuries rather than taking three milenia.142.0.102.164 (talk) 16:53, 29 April 2015 (UTC)
thread_title:  The melting ice sheet 

message: I know scientists are very careful not to say anything about this, but what are the estimates of the time Greenland Ice Sheet takes to melt ?  1500 years (as in the end of the last ice age) - 150 years (as there's ~10 times less ice than in the last ice age)?   —Preceding unsigned comment added by 91.153.60.138 (talk) 07:23, August 26, 2007 (UTC) 
- Quick answer:  We don't know.  Between 50 and 1500 years..  —Preceding unsigned comment added by 87.86.252.131 (talk) 10:21, August 28, 2007 (UTC) 
Great example of scientific innumeracy from questioner and answerer. Time frame = amount of ice/loss rate = 3 million / 200 = 15,000 years roughly. Of course this calculation is not done in the article because the answer is not sufficiently alarming.  —Preceding unsigned comment added by 128.243.220.42 (talk) 15:04, 8 October 2007 (UTC)
replies: text: It's actually more complicated than that. There can be strongly non-linear effects, such as pools of water forming that absorb sunlight much more efficiently than ice, and liquid water build-up below the ice that carries large blocks out into the sea. But even without such effects the ice-loss rate is going to change significantly due to climate change. It could increase (due to higher temperatures) or decrease (due to increased precipitation at high altitude). The most pessimistic scenario in the IPCC graph shown in the article has most of the ice gone by the year 3000. (The graph shows a 600 cm sea level rise, and a 720 cm rise would correspond to all of the ice sheet.) --PeR 19:59, 9 October 2007 (UTC)

text: Side-effects of ponding were important with the Larsen Ice Shelf collapse. While that was over sea, the role of ponding is somewhat measured in the Greenland ice sheet -
*Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow Originally published in Science Express on 6 June 2002, Science 12 July 2002: Vol. 297. no. 5579, pp. 218 - 222 "The near coincidence of the ice acceleration with the duration of surface melting, followed by deceleration after the melting ceases... provides a mechanism for rapid, large-scale, dynamic responses of ice sheets to climate warming."
*Evolution of melt pond volume on the surface of the Greenland Ice Sheet GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L03501, "estimating the depth and hence volume of surface melt ponds... show large intra- and interannual changes in ponded water volumes, and large volumes of liquid water stored in extensive slush zones."
Then add the tracking of accumulated changes by ponding causing accelerated change in the ice sheet in the earthquake record ....
*Global warming yields 'glacial earthquakes' in polar areas "Glacial earthquakes in Greenland, the researchers found, are most common in July and August, and have more than doubled in number since 2002." - 
*Glacial earthquakes rock Greenland ice sheet 12:36 24 March 2006, NewScientist.com news service " quakes ranged from six to 15 per year from 1993 to 2002, then jumped to 20 in 2003, 23 in 2004, and 32 in the first 10 months of 2005."
Another dynamic of melting ice happens with such events as the Missoula Floods.--Smkolins (talk) 01:14, 12 January 2008 (UTC)
replies: text:  Allow the rate of increase in global warming increases at an increasing rate with periodic discordant surges as the tipping points tip, three earth atmospheres of methane get released, the sea ice melts affecting the albedo, human population doubles by the end of the century doubling the anthropogenic effects, eventually the result is the sixth global extinction event, but factor in also the SLR from West Antarctica and now the Totten glacier in East Antarctica. Add to that the shift from el Nino to La Nina acts to put more heat in the atmosphere than in the oceans where it has been being stored then model that either as doubling or the Fibonacci series and it gets interesting. Using the Rules of 72, 70, or 69 you just divide the rate into the rule to get the doubling time. With the rule of seventy and a rate of one percent the melting rate takes 70 years to double. Suppose the rate increases at an increasing rate as the Fibonacci series 1,1,2,3,5,8... much like what we observe with temperature and sea level rise, we might see Greenland melt in a couple of centuries rather than taking three milenia.142.0.102.164 (talk) 16:53, 29 April 2015 (UTC)
thread_title:  Time frame of the melting ? 

message: "Because the overwhelming majority of humans in the world live near the water, it would inundated almost every major coastal city in the world, absent heroic mitigation."
does not make sense.
1) IF TRUE? then regardless of the number of people living near water, it would still inundate (not -inundated) almost every major coastal city in the world.
2) also "absent heroic mitigation" does not reflect any fact, and thus does not belong in an encyclopedia.
My suggestion is:
1) delete it altogether, or
2) change it to: "This would inundate most coastal cities in the world and remove several small island countries from the face of Earth." —Preceding unsigned comment added by 24.106.210.234 (talk • contribs) 
:I've noticed that too... I've followed your suggestion. --Bletch 14:39, 1 October 2006 (UTC)
thread_title:  Sentence needs reconsideration 

message: It's worthy of note that the mass loss is due more to the ice flow in the outlet glaciers than to melting on the ice sheet (at least since 1996).  Should the section on melting be rewritten to reflect this?  71.32.19.55 (talk) 01:31, 25 May 2008 (UTC)
thread_title:  Mass loss is more due to flow of ice though outlet glaciers than melting 

message: This news story...
http://www.latimes.com/news/science/la-sci-greenland23-2008aug23,0,750881.story
...claims Petermann Glacier has a huge crack, and is about to calve a mega-iceberg.
Could someone who knows anything about the situation Wikify Petermann Glacier, then, maybe, point to the crack on those satellite photos? They all look like a bunch of ice to us civilians.  —Preceding unsigned comment added by 76.212.171.42 (talk) 20:47, 24 August 2008 (UTC)
replies: text: Certainly some cracking. Here is the Google maps sat picture... https://www.google.com/maps/place/Greenland/@80.3531993,-56.254893,277041m/data=!3m1!1e3!4m5!3m4!1s0x4ea20dbbe3c07715:0x34cf9d830114e218!8m2!3d71.706936!4d-42.604303 Tatlayoko (talk) 21:24, 24 March 2021 (UTC)
thread_title:  Where's the crack?? 

message: *http://de.wikipedia.org/wiki/Grönländischer_Eisschild#Einzelnachweise
Also der Wikipedia Artikel beruht auf Quellen des IPCC. Die Groesse des Eisschildes Greenlandes wird mit 1.700.000 Quadratkilometer angeben. Haben die beim IPCC einen Erdglobus? Bei dem koennen sie das Gradssytem der Nordhalbkugel sehr gut betrachten, dieses unterteilt die Nordhalbkugel in 90 Kreise. Davon umfasst der Nordpol mit 90 Grad und 360 Graden eine Flaeche von Null Quadratmetern. Und nun behaupten die Referenzquellen auf die Kreisflaechen zwischen dem 83 Grad und dem 63 Grad bzw. dem 20 bis 60 Grad (Hauptflaeche liegt zwischen dem 30 und 50 Grad) soll eine Flaeche von 1.700.000.000 Quadratmetern passen. Ohne das genau auszurechnen, schaetze ich mal, dass es als Mathematiker und Geograph unmoeglich ist, bei diesen Gradzahlen des Erdglobuses von Groenland eine Flaeche 1.700.000.000 Quadratmeter Eisschild unterzubringen, rein mathematisch (Kreisflaechenberechnung Kugelberechung) und geographisch unmoeglich ist (koennen sie auch mit einem Zirkel nachpruefen). 
Ich schaetze das Eisschild von Greenland hat auf Grund von Mathematischen und Geographischen Gegebenheiten eine moegliche Groesse von 170 Millionen bis 350 Millionen Quadratmetern. Das gleiche gilt wahrscheinlich auch genauso fuer das Antarktische  Eisschild, dass im Greenland Eisschild Artikel Wikipedia erwaehnt wird (Link).
:Nehmen Sie mal ein A1 Blatt Papier. Zeichnen Sie mit einem Zirkel da einen Kreis von 90 Zentimeter. Der Mittelpunkt davon ist (Erdglobus) der  Nordpol. Nun zeichne sie weitere 89 Kreise auf das Blatt Papier. Nun makieren sie die Koordinaten von Greenland und des Greenland Eisschilds. Als naechstes berechnen sie fuer jeden der 90 Kreise den Radius, den Durchmesser, den Kreisumfang, die Kreisflaeche (Erdenordhalbkugel in 90 Scheiben geschnitten). Das schwierigste ist nun die Flaechen zwischen zwei Kreisumfaengen zu berechnen. Als letztes muessen sie nun die Daten des groessten  Kreisumfanges in die Zeichnung einrechnen, unzwar die des 40.085 Kilometer langen Aequators (90:40.085). 
:In der gleichen Weise koennen sie mit einem Zirkel auch die Flaeche der Antarktis und des Antartischen Eisschildes zeichnen und berechnen. 
*http://de.wikipedia.org/wiki/Antarktischer_Eisschild
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http://rapidshare.com/files/309919401/FOI2009.zip
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:82.109.84.114 (talk) 14:29, 23 November 2009 (UTC)
thread_title: "1700.000 km²"

message: The statement had been that "at this rate, it would melt in 11,900" years and had cited a 2001 report by IPCC. Since this report is not the msot recent, I had earlier today updated the sentence to "At this rate of ice loss the IPCC estimated in 2001 that  Greenland ice sheet would melt in 11,900 years" However there are several additional problems:
* 1. The previous sentence was about 2006 estimates (loss of 239 km^3/yr). It thus makes no sense to start this sentence with "at this rate..." and then cite a 2001 IPCC report which would obviously not have used the 2006 estimate. At best the sentence should be, "using similar estimates back in 2001..."
* 2. A bigger problem that no direct reference to "11,900 years" or to the year 13,900A.D. is in the reference cited
* 3. he biggest problem comes from a misleading and scientifically inaccurate interpretation of the annual melt as a percent of total mass. One of the numbers in the reference may have been used by the editor who put in the "11,900" years, though it's not clearly stated. This, in any event, is scientifically inaccurate, namely there is no prediction for melting to take 11,900 years. The melt rates are not predicted to be linear, or in more basic terms, they are not predicted to continue at a constant rate.  Thus "11,900 years" even if it were citing a reference which gave something like "annual melt is equal to 0.007% or 0.008% of the total mass" (an annual melt which, if kept constant would cause 11,900 or so years to be 'how long total melt would take') it would still be inaccurate and misleading since there is no scientific prediction of the melt rate being constant. Quite to the contrary, it is expected to be highly nonlinear. Not only that, it's not only expectations but the data show more recent melt rates to be much higher than those only 10 or so years earlier.
For all these reasons and especially the third, I've removed this sentence. (The 2001 reference (currently ref [2] in the article) is still there and is cited in other parts of the article. For useful background  on point 3. see  foremost; also ) Harel (talk) 19:36, 16 August 2010 (UTC)
thread_title:  "11,900 years" 

message: The Al Gore, and the other Climate Change is all America's fault forget to mention that millions of years ago when there was no connection between South America, and Central/North America. The Panama Gap was wide open for any ship or whale to pass from the Atlantic to the Pacific, there was no northern ice pack at all. The climate was very warm. I am unsure what prehistoric automobile company was to blame. The fact is the climate would change on earth regardless of what creature is at the top of the food chain.  —Preceding unsigned comment added by 98.248.200.121 (talk) 21:49, 30 January 2011 (UTC)
replies: text: Using "Al Gore" in any comment on this page is an excellent way to get precisely nobody to take it seriously. If you find specific inaccuracies in the article, please post them along with verifiable sources to back up your claims. Otherwise, Wikipedia Is Not A Discussion Forum. Matteric (talk) 23:03, 17 November 2012 (UTC)
thread_title:  Northern Ice Cap is only a recent occurrance in geological time. 

message: why there is ice sheet on greenland while not near it in canada and not in similar places in siberia? i have found this: http://200.ksu.ru/index.php?sci_news=451 , http://www.eurekalert.org/pub_releases/2008-08/uob-wig082608.php . so, it is unknown by modern science. --Qdinar (talk) 06:30, 7 April 2012 (UTC)
replies: text: One can't make this conclusion "unknown by modern science" from just two reports.  As a Wikipedia editor: if these two sources meet WP:RS, they could be used to add balance and an WP:NPOV to the article. Lentower (talk) 07:37, 7 April 2012 (UTC)
replies: text:  The reason why Greenland has ice and Canada does not is precipitation. The Canadian arctic is EXTREMELY dry compared to Greenland.Tatlayoko (talk) 21:28, 24 March 2021 (UTC)
thread_title:  why there is ice sheet on greenland while not near it? 

message: The section on surface melting only mentions data up to 2002. This needs to be updated with considerations of more recent events, notably, the period in mid-July 2012 where something like 97% of the surface area of the ice sheet experienced melting. EthicsEdinburgh (talk) 21:08, 26 July 2012 (UTC)
thread_title:  July 2012 melt event 

message: If the temperature is projected to increase to where tipping points such as methane releases occur
generating feedback loops where the melting occurs faster, and scientists already observe the rate
of melting is showing surprising acceleration, won't the thousands of years presently projected for
the ice caps to melt completely be reduced as substantially as the warming is increased? On other words,
is it correct that if the rate of warming is doubled the time of melting would be halved, and if multiplied
by a factor of ten the same? 12.187.94.154 (talk) 17:18, 18 April 2013 (UTC)
thread_title:  rate of melt increasing at an increasing rate 

message: It is currently stated that the melting of the ice sheet would result in a 7.2 metre rise in sea level. However an article in Nature implies up to a 13 metre rise, to quote: "global mean sea level 6 to 13  metres above the present level around 410,000 to 400,000 years ago, implying substantial mass loss from the Greenland ice sheet". http://www.nature.com/nature/journal/v510/n7506/full/nature13456.htmlRoyalcourtier (talk) 19:43, 25 June 2014 (UTC)
replies: text: The 7 m figure is the most common estimate, the study you cite is from 2014 which might suggest that the figure needs to be revised upwards. Maybe if we get another recent study with a similar estimate we change the article? Or we could add a mention that a study from 2014 estimates up to 13 m.prokaryotes (talk) 08:57, 27 August 2015 (UTC)
thread_title:  Increase in mean sea level 

message: The ice sheet, consisting of layers of compressed snow from more than 100,000 years, contains in its ice today's most valuable record of past climates.
Claiming that it is the most valuable record is quite presumptive. What about the Antarctic ice cores that go back further in time are they not more valuable since they hold more information?
Haloway13 (talk) 20:52, 23 June 2016 (UTC)
thread_title:  Extraordinary claim? 

message: Hello fellow Wikipedians,
I have just modified 4 external links on Greenland ice sheet. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
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*Added archive https://web.archive.org/web/20111022020035/http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_2.pdf to http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_2.pdf
*Added archive https://web.archive.org/web/20081224121803/http://geography.swan.ac.uk/glaciology/adrian/luckman_GRL_feb06.pdf to http://geography.swan.ac.uk/glaciology/adrian/luckman_GRL_feb06.pdf
*Added archive https://web.archive.org/web/20061003013255/http://www.jpl.nasa.gov/news/news-print.cfm?release=2006-023 to http://www.jpl.nasa.gov/news/news-print.cfm?release=2006-023
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thread_title:  External links modified 

message: This article seems extremely lacking in information on the actual ice sheet itself, seemingly like a lot of others. Compare to Ross Ice Shelf for a more relevant article on a similar feature. Has anyone considered reworking this to be more about the ice sheet itself and less about climate change? 156.57.210.83 (talk) 17:52, 28 August 2018 (UTC)
replies: text: What do you think is missing about the ice sheet itself (and which does not involve our climate)? prokaryotes (talk) 18:26, 28 August 2018 (UTC)
replies: text: exploration....   NewsAndEventsGuy (talk) 11:56, 29 August 2018 (UTC)

text: Something about its influence on culture, history, settlement, and politics... coordinate that with text at Greenland NewsAndEventsGuy (talk) 11:59, 29 August 2018 (UTC)
thread_title:  Hyperfocus on global warming? 

message: Nonlinear rise in Greenland runoff in response to post-industrial Arctic warming Science News summary
A new method for observationally determining past melt rates is developed and pre-industrial rates are compared to the present day. Rates are increasing and will continue to increase with further warming.
From the abstract
:"continuous, multi-century and observationally constrained record of GrIS surface melt intensity and runoff, revealing that the magnitude of recent GrIS melting is exceptional over at least the last 350 years" ... and ... "We find that the initiation of increases in GrIS melting closely follow the onset of industrial-era Arctic warming in the mid-1800s, but that the magnitude of GrIS melting has only recently emerged beyond the range of natural variability. Owing to a nonlinear response of surface melting to increasing summer air temperatures, continued atmospheric warming will lead to rapid increases in GrIS runoff and sea-level contributions."
The nonlinearity of melt response is key and it helps to address questions below about time to melt the ice sheet and so on.
Ecwiebe (talk) 17:28, 6 December 2018 (UTC)
thread_title:  Latest research as of 2018-12-05 needs to be incorporated 

message: The article says "Indlandsis" is the Danish term for the ice cap, but in Danish, we actually say "Indlandsisen". The last -en is the definitive article. We use the definitive, because Indlandsisen only refers to the Greenland Ice Cap. 77.233.228.141 (talk) 09:02, 7 August 2020 (UTC)
thread_title:  Danish word for the ice cap 

message: Reworking this big article is a big project, but for anybody who wants to dig in, I found some good recent RS. HouseOfChange (talk) 01:25, 16 September 2021 (UTC)
thread_title:  More recent information from RS 

message: Suggest some of the numbers be demoted to the body and a few sentences about “Description” and “Geophysical and biochemical role of Greenland's meltwater” added  Chidgk1 (talk) 20:27, 4 February 2024 (UTC)
thread_title:  Suggestion for lead 

message: Hi User:Amitchell125, I saw your comment in the GA review about section headings: . I took a look but don't know which section headings you think should be shortened and how? None of them are overly long, given that they are not main level headings but sub-headings. EMsmile (talk) 19:13, 19 March 2024 (UTC)
thread_title:  Section headings