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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Is Greenland gaining or losing ice?

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Greenland on the whole is losing ice, as confirmed by multiple satellite and on the ground field measurements.

Climate Myth...

Greenland is gaining ice

“[E]ven if it were true that Greenland’s ice had been melting at ‘new record’ rates, after seven and a half years of global cooling global warming cannot be the cause. The true position in Greenland is to be found in Johannessen et al. (2005), where satellite altimetry established that the mean thickness of the entire Greenland ice sheet had increased at 2 inches per year – a total of almost 2 feet – in the 11 years 1993-2003.” (Christopher Monckton)

At a glance

The interior of Greenland features a huge ice sheet that covers some 80% of that large island. Up to three kilometres thick, the sheet contains a whopping 2.9 million cubic kilometres of ice. If that all melted, global sea level would go up by around seven and a half metres. So it would obviously be good if that didn't happen.

Read any science about ice-sheets and you will soon run into a term that will become familiar: 'mass balance'. Mass balance is an expression of the health of any ice-sheet. Ice-sheets gain mass by snowfall and lose mass by 'ablation', a term covering sublimation, evaporation melt, and meltwater runoff, plus solid ice discharge by the glaciers that drain them. If the value for mass balance of an ice sheet is a positive number, the sheet is growing. But a negative value means the sheet is dwindling.

Since 1991, satellites have obtained continuous data on the Greenland ice-sheet, using radar, lasers and sensitive instruments that can detect changes in local gravity. Such methods allow mass balance to be calculated.

With over 30 years of satellite data now at our disposal, we can step back and look at the big picture. The Greenland ice sheet was close to a neutral state of balance in the 1990s. Since then however, annual losses have risen. One recent paper calculates that Greenland lost almost 4,000 billion tonnes of ice between 1992 and 2018, adding almost eleven millimetres to global sea levels.

Reduction of ice mass balance has occurred for two key reasons. Firstly there is increased meltwater run-off. Have you seen imagery of bright blue pools connected to rivers, flowing across the surface of the ice-sheet, to disappear down into it in spectacular cascades? That's the run-off. Secondly, there is glacier instability - whereby glaciers speed up in their discharge of ice, ultimately to the ocean, with those videos of spectacular calving events many of you will have seen. In Greenland, it's thought that these two processes account for about half of ice-sheet loss each.

Of course, the rate of ice loss varies from year to year. It depends on weather patterns. A cooler year with a lot of snowfall will provide a considerable counter-weight to the loss processes. Then again, in June 2023 the temperature rose to 0.4^oC at the Summit Station, a research facility situated 3,216 metres above sea level and near the high-point of the ice-sheet. That has only happened five times in the 34 years since the station was established. Like anywhere else, the year to year pattern is pretty varied: however it's the multidecadal trend that matters and that is very definitely downwards.

It never pays to pick short time-spans when discussing matters of long-term climate trends. Statements like the one by Christopher Monckton in the myth-box above, made in 2009, have simply been made invalid by the march of time.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

Further details

Anecdotes of structures on the Greenland Ice Sheet, such as the now disused Dye 2 and 3 Cold War radar stations being engulfed by snow, have led to claims in some quarters that Greenland is gaining ice. However, a couple of isolated radar stations are not representative of the whole ice-sheet and the late 2000s, when the claims were made, is a long time ago now. So let's take a look at how ice-sheets are evaluated and what has happened since.

On any ice-sheet, ice loss occurs because of surface melt, wind-ablation and sublimation. Surface meltwater finds its way down through crevasse systems to the bed of the glacier, there lubricating and accelerating its down-slope motion. Where ice-shelves around the coastline are lost through melting and/or collapse, the loss of their buttressing effect has the same result, as it also does when warm water causes grounding line retreat. All of these processes are intensified by increased warmth.

Although on-site measurement techniques are used by glaciologists, it has become standard practice to use satellites for large scale monitoring. Satellites return data from extensive areas of remote terrain that would require expeditions to reach. Three key measuring parameters are employed to obtain ice-sheet data. These comprise elevation change, mass change and flux components. The first satellites capable of such measurements were launched in the very early 1990s, ERS-1 in 1991 and ERS-2 in 1995. Thus, the satellite record of ice sheet change is now multidecadal.

Elevation change

The elevation of the Greenland ice-sheet is measured using both laser and radar altimetry. In both cases a signal is fired at the surface of the ice and bounced back. Both radar and laser waves travel at the speed of light, so recording the time they take to return to the satellite means the distance travelled may be calculated. Radar altimeter signals provide good coverage for ice sheets. However, at first there were some resolution issues, causing difficulties in measuring sloped/rough terrain. Laser altimetry is also highly accurate and has an even better resolution than radar altimeters but cloud cover can be an issue.

Radar altimeter signals also penetrate the near-surface uncompacted snow and ice layer. This can introduce a bias into the data. Those who work on such programmes are well aware of such issues. In 2010, Cryosat-2 was placed in orbit, equipped with a much higher resolution radar altimeter. This altimeter uses complex radar combination techniques, known as radar interferometry, to enhance horizontal resolution. That allows more precise measurements of changes in ice elevation of as small as a few centimetres. A further benefit of Cryosat 2 is that it allows for the highest latitude coverage available for an altimeter. Measurements can be taken right up to 88° north. Continuing the theme of better and better equipment, the next generation of monitoring satellites, Sentinel 3a and 3b, were launched in 2016 and 2018 respectively.

Mass Changes

Gravimetry measures changes in regional gravitational fields through accurate measurements of the gravitational pull on satellites as they overfly a district. As an ice-sheet gains or loses mass through time, regional gravitational forces are affected. Measuring these effects makes mass change estimates possible. The technique involves precise monitoring of the separation between a pair of satellites in identical orbits. This was one purpose of the space mission that has changed the way we study Earth's gravitational forces. It is called the Gravity Recovery and Climate Experiment, or GRACE, and was launched in 2002. The GRACE mission ended in 2017 but these highly innovative techniques were continued on GRACE-FO (GRACE Follow-On), launched in 2018.

Flux Component Method

The flux component method involves the estimation of the total mass input and mass output for each individual glacial drainage-system. Put together, these values allow us to estimate the situation for the whole ice sheet. Mass input estimates require detailed knowledge of patterns of snow accumulation, in both space and time. On site observations of glacier mass involve meteorological records, snow pits, ice cores and marker poles. These are used to ground truth regional ice-sheet models. Good agreement between modelling and measurements give confidence in the usefulness of the method.

Outflow estimates involve recording the speed of the ice flow and the thickness of the ice. Radar Interferometry allows for direct all-weather recording of surface velocities. Depth of ice streams has been estimated using various means, from bedrock topography models to ground penetrating radar surveys.

Satellite-based observations have been used to record ice surface velocity, although the velocity of an ice sheet often varies with depth, introducing some uncertainty. Outlet glaciers, though, tend to move by rapid basal sliding. Such ice-streams therefore have minimal variation in speed with depth.

Fig. 1: GRACE and GRACE-FO satellite gravimetry-based mass balance, representing the total mass change in the Greenland Ice-sheet in gigatons (Gt) from April 2002 to September 2023. Source: NOAA Arctic Report Card 2023, page 33.

The results of these various missions all point at one thing (e.g. Fig. 1). Net negative mass balance - ice loss has dominated every year since 1998. It's highly variable, though as the weather fluctuates. Some winters see much greater snow accumulation than others. Some summers are warmer than others. Just as an example, in the one year period from 1 September 2022 too 31 August 2023, GRACE-FO measured a total GIS mass balance of -156 +/- 22 Gt. That equates to 0.4 mm of sea level rise in 12 months. However, the year was a below-average one for ice-melt. Yet by the 2010-2018 period, average annual ice-loss was six times that of the 1990s (Mouginot et al. 2019).

An extensive literature exists on the methodology of and results from ice-sheet monitoring on Greenland from the early days (e.g. Johannessen et al. 2005) to the present (e.g. Shepherd et al. 2019; Mankoff et al. 2021 and references therein). However, NOAA's annual Arctic Report Card is a good place to start exploring, with much more extensive literature citations than is possible here.

Last updated on 19 February 2024 by John Mason. View Archives

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Further viewing

This video published on December 15, 2019 by Dave Borlace of "Just have a think" provides information about a new study finding that Greenland is melting seven times faster than 30 years ago .

Comments

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Comments 1 to 25 out of 46:

Quietman at 11:43 AM on 5 September, 2008
There is no argument of overall ice loss in Greenland. The glacial growth is not keeping up with glacial loss. The argument is the cause. Without the additional heat loss from the earth (vulcanism) through both tectonics and volcanism it might not be a net loss. In other words the reason behind Greenland's and the Arctics ice melt is in question. See the volcano thread.
Quietman at 10:10 AM on 11 October, 2008
However: Science 4 July 2008: Vol. 321. no. 5885, pp. 111 - 113 DOI: 10.1126/science.1158540 Reports Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet R. S. W. van de Wal,* W. Boot, M. R. van den Broeke, C. J. P. P. Smeets, C. H. Reijmer, J. J. A. Donker, J. Oerlemans Continuous Global Positioning System observations reveal rapid and large ice velocity fluctuations in the western ablation zone of the Greenland Ice Sheet. Within days, ice velocity reacts to increased meltwater production and increases by a factor of 4. Such a response is much stronger and much faster than previously reported. Over a longer period of 17 years, annual ice velocities have decreased slightly, which suggests that the englacial hydraulic system adjusts constantly to the variable meltwater input, which results in a more or less constant ice flux over the years. The positive-feedback mechanism between melt rate and ice velocity appears to be a seasonal process that may have only a limited effect on the response of the ice sheet to climate warming over the next decades. Institute for Marine and Atmospheric research Utrecht, Utrecht University, Netherlands.
From Peru at 08:15 AM on 25 January, 2010
The Michiel van den Broeke, et al. paper "Partitioning Recent Greenland Mass Loss" states: "Our results show that both mass balance components, SMB and D (eq. S1), contributed equally to the post-1996 cumulative GrIS mass loss (Fig. 2A)." But then, Fig.3 shows: Ice Discharge: -94 Gt/yr Surface Mass Balance: -144 Gt/yr Isn't this a contradiction? Then comes this statement: "A quadratic decrease (r^2 = 0.97) explains the2000–2008 cumulative mass anomaly better thana linear fit (r^2 = 0.90). Equation S1 implies thatwhen SMB-D is negative but constant in time, ice sheet mass will decrease linearly in time. If, however, SMB-D decreases linearly in time, ashas been approximately the case since 2000 (fig.S3), ice sheet mass is indeed expected to decrease quadratically in time" What is this "r^2 = 0.97" and how it is related to the equations: MB = ∂M/∂t = SMB – D (S1) δM = ∫dt (SMB-D) = t (SMB0–D0) + ∫dt (δSMB–δD) (S4) Any idea?
Riccardo at 09:45 AM on 25 January, 2010
From Peru, in fig. 3 they show mass change for the period 2003-2008; fig. 2A shows the cumulative mass loss from 1960. The former is a rate of mass loss, the latter just a mass. r^2 is the so called coefficient of determination. In the case of a simple linear fit it's equal to the square of the correlation coefficient. You may (crudely) interpret it as the fraction of the variation explained by the model curve.
cynicus at 04:00 AM on 3 September, 2010
New research on the GRACE results argues there's exaggeration of the ice loss in Greenland and Antarctica data. The current estimates are supposed to ignore isostatic rebound caused by the weight reduction pressing down on the bedrock through the lost ice mass. E.g. this new report claims that the true loss in Greenland is only half of the previously reported 230 Gt per year. This spectacular reduction is, ofcourse, trumpeted around in the media and denial blogs as exiting news, but 104 Gt per year brings it right into the IPCC 2007 ballpark of 100+ Gt per year. It is, however, much lower then the latest GRACE numbers as published by Velicogna et al. 2009 and 2007, but in the same ballpark as GRACE numbers from Luthcke et al. 2007. The concept of isostatic rebound effecting the GRACE mass numbers isn't new either as it was already mentioned in e.g. the . It just puts some numbers to it. There's another, somewhat older, that delves into the apparent GRACE overestimation by comparing IceSat to GRACE results. But instead of isostatic rebound it seeks to explain the differences with ice density uncertainties. It also gives an IceSat number of -138 Gt per year for Greenland which is roughly equal to the results of this new research. So I don't know exactly what the great joy of this report is supposed to be for the contrarians. It just seems to me as confirming, refining and consolidating the science behind the apparent shrinking ice sheets.

cynicus at 04:08 AM on 3 September, 2010
Sorry, I messed up two hyperlinks. Here they are: ... mentioned in e.g. the IPCC 2007 report. There's another, somewhat older research, ...
muoncounter at 10:10 AM on 24 January, 2011
Beautiful website about Greenland ice loss. Remote sensing data, surface observations and models indicate new records in 2010 for surface melt and albedo, runoff, the number of days when bare ice is exposed and surface mass balance of the Greenland ice sheet. This was especially true over over its west and southwest regions. Anyone not see the trend? In simple words, each bar tells us by how many standard deviations melting in a particular year was above the average. For example, a value of ~ 2 for 2010 means that melting was above the average by two times the ‘variability’ of the melting signal along the period of observation.
John Hartz at 08:55 AM on 24 February, 2011
There's a new peer-reviewed paper on this topic: "The role of albedo and accumulation in the 2010 melting record in Greenland" by M Tedesco, et al, Environmetal Research Letters #6 (January-March 2011) This paper can be accessed for free at: http://iopscience.iop.org/1748-9326/6/1/014005/fulltext
Response: [muoncounter] See also the discussion on the Flanner thread.
DSL at 01:26 AM on 22 August, 2011
Here's a story from the human perspective--Inuit Greenlanders and their changing culture due to changes in ice. It was published in Business Week of all things. Of course, it does hit on the drill, baby, drill aspect of Arctic change.
Zihaya at 17:55 PM on 28 September, 2011
We need accurate data from any source materials for a valid result. But there is a re-draw map controversy. Times Atlas is at the middle of a debate after publishing a map that revealed a 15 percent decrease in ice mass. Greenland ice mass maps causing political uproar . Greenland is losing some ice mass due to melting. Environmental change due to global warming brings big changes.
skywatcher at 18:22 PM on 28 September, 2011
The Times atlas controversy appears quite ridiculous. They initially very publicly claimed Greenland had lost 15% of its area, then had to start backpedalling as the complaints from the cryospheric community came rolling in (see RealClimate for a summary). mainly because the Times Atlas in their various statements kept claiming initially that their maps were accurate, then that it was not their fault, it was the fault of the NSIDC, then in their latest concession claim it highlights uncertainty in climate science! Yet all it does is highlight their own incompetence, in taking a >500m thickness map and thinking that this showed ice extent. From HarperCollins' last statement: "The one thing that is very apparent is that there is no clarity in the scientific and cartographic community on this issue ... ". Dead wrong. There is plenty of clarity on the issue in the science community, it's just that the Times Atlas cartographers got it totally wrong and can't admit it. In the age of Google Earth and freely-available MODIS imagery, as well as with a media engine keen to highlight "uncertainties" in climate science, such an error, which clouds public understanding of Greenland's actual melt, verges on the unforgivable.
Response:
[DB] "the Times Atlas cartographers got it totally wrong and can't admit it."

As one who spent many years as a professional cartographer, this statement (and your closing paragraph) are spot-on.

The mind boggles.
Maggnum at 03:47 AM on 23 January, 2015

Last updated Nov 2011? I think this needs an update! Come on John, I'm sure you have nothing but time on your hands. :)
william5331 at 16:25 PM on 3 June, 2015

I wonder if a Walker type cell could develop between the ever warming Arctic Ocean and the Greenland Ice sheet. Rising warm air contacts the ice, cools and flows down the ice sheet warming by compression and giving its heat to the ice. Warm foen winds cause extreme melting when in contact with ice.
bozzza at 17:12 PM on 3 June, 2015

... interesting: I wish I knew the answer to your question!
John Hartz at 05:14 AM on 4 November, 2017

Recommended supplemental reading:
New Greenland maps show more glaciers at risk by Carol Rasmussen, NASA's Global Climate Change, Nov 1, 2017
Cedders at 23:33 PM on 11 November, 2017

I've noticed new claims that Greenland is gaining ice. It seems Steven Goddard (Tony Heller) a graph by Danish researchers on a web page 'Current Surface Mass Budget of the Greenland Ice Sheet'. It was picked up in Goddard's "Deplorable Climate Science Blog" as "Massive Growth In Arctic Ice Since Last Year" and that has been amplified by contrarians who in this case prefer to believe models to satellite data (eg "Grace data update reveals NASA Greenland mass-loss fraud").
The confusion is simply resolved by reading the explanatory text.
Over the year, it snows more than it melts, but calving of icebergs also adds to the total mass budget of the ice sheet. Satellite observations over the last decade show that the ice sheet is not in balance. The calving loss is greater than the gain from surface mass balance, and Greenland is losing mass at about 200 Gt/yr.
John Hartz at 05:05 AM on 12 November, 2017

Ceddars @16: Based on your summary, Heller seems to be conflating Arctic sea ice with the Greenland ice sheets. Is that the case? (I personally do not wish visit Heller's blog to find out.)
michael sweet at 09:52 AM on 12 November, 2017

John,
The graph Ceddars linked to (apparently from Goddard's site) is a graph of yearly snowfall and surface snow melt on Greenland.
The paragraph Ceddars quoted correctly describes that more snow falls each year than melts (I think in 2012 more snow melted but most years more snow falls than melts). The graph does not include melting of glaciers or calving of icebergs so it is not a complete record of Greenland ice.
The GRACE gravity data show that more ice melts each year than falls as snow. GRACE measures surface melt and ocean melt.
Cedders at 18:47 PM on 12 November, 2017

Sorry, there was an important word missing in my post 16 - Goddard Heller 'misrepresented' the graph, but I was going to be charitable and write 'misinterpreted'. However, it's possible he personally understands the difference between surface and total mass balance but has avoided explaining it.
The minimal text in 'Massive Growth In Arctic Ice Since Last Year' (Nov 2017) concerns both sea ice and the Greenland Ice sheet - it makes no claim the two things are related but leaves readers to draw a conclusion. Previous uses of the DMI graph includes 'Greenland Ice Growth Ahead Of Last Year’s Record Pace' (Oct 2017) which seems oddly careful to specify that DMI does show surface mass balance given that it goes on to talk of 'criminals in the press and academia'; 'Record Greenland Ice Growth Continues' (Sep 2017); 'Scientists Discover That Their Imaginary Greenland Meltdown Is Not Having Any Effect' (June 2016); and over at NTZ 'Danish Meteorological Institute Moves To Obscure Recent Record Greenland Ice Growth' (Gosselin, April 2017) mentions 'massive ice growth' without any sign of being aware of calving loss.
On 24 April Goddard Heller tweeted 'Contrary to the lies of government scientists, Greenland has gained a record 600 billion tons of ice this winter.' I pointed out the possible source of confusion, and Goddard blocked me shortly thereafter.

Response:
[JH] Please use Heller's real name.
MA Rodger at 20:40 PM on 12 November, 2017

To clarify the situation regardingGoddard/Heller's use of DMI graphics.
He shows the DMI Accumulative Surface Mass Balance graph (the lower one of the above) in two of his November posts (so far). In the first of these posts (Nov 1) he says "Greenland ice growth is close to last autumn’s record high." (His screen-shot of the graphic does not past Nov 1.) This strongly suggests Heller/Goddard doesn't understand AccSMB.
This was preceeded by a graphic showing the differences between two NOAA SIE graphics aserting "Arctic sea ice extent is up 16% from last year."
This is perhaps no surprise. 2016 was jaw-droppingly un-icy through the Autumn, setting new records for low ice. Using JAXA daily data, 2017 was 14% above 2016 on 30 Oct (& almost 16% up on 2016 on 18 Oct. Yet a percentage is a little silly as a measure - SIE grows over 50% through the month of October). And of course, the whole comment is silly as 2017 remains a very un-icy year, as shown in this JAXA SIE anomaly graphic (usually 2 clicks to 'download your attachment'). 2017 SIE is at present in 3rd place behind 2012 & 2016.
In a second post (Nov 9) Goddard/Heller again posts the DMI Acc SMB graph saying "The last two years have seen near record ice gain in Greenland." Additionally, to back his primary assertion that there has been a massive expansion of thick ice over the last decade, he blinks two DMI graphs (below) but with the thinner sub 1.5m blue and purple sea ice whited out. While the areas of thick ice may be greater 2007-17 as Heller/Goddard says, PIOMAS shows a healthy drop in total sea ice volume between Oct 2007 and Oct 2017 of 990 cu km.
warissara.su at 01:00 AM on 27 March, 2018

I understand that Greenland is not gaining ice now after the 2000s and it decreases over 300 billions of tons of ice every year. Because of the world temperature increases can cause too much ice loss so it cannot change all of the water from ice to precipitate all of it at the interior. But why Greenland is highly sensitive to warmer temperatures?
Daniel Bailey at 21:01 PM on 27 March, 2018

"But why Greenland is highly sensitive to warmer temperatures?"
Partly because, due to its latitude, it gets a lot of summer insolation from the sun (much more so than does the Antarctic Ice Sheet), and partly due to its proximity to warming ocean currents. Poleward convective energy transportation systems do the rest (helping to raise the ablation line higher up the ice sheet, driving further mass balance changes).
Sarmata at 00:06 AM on 7 November, 2018

Contrasting temperature trends across the ice-free part of Greenland (25 January 2018)
https://www.nature.com/articles/s41598-018-19992-w
"less than 36% of the ice-free Greenland has experienced a significant trend and, if any, a cooling is observed during the last 15 years (<0.15 °C change per year)."
"Warming trends observed from 1986–2016 across the ice-free Greenland is mainly related to warming in the 1990’s. The most recent and detailed trends based on MODIS (2001–2015) shows contrasting trends across Greenland, and if any general trend it is mostly a cooling. The MODIS dataset provides a unique detailed picture of spatiotemporally distributed changes during the last 15 years."
So why is there less ice if it's overall cooling?
https://www.nationalgeographic.com/environment/2018/09/news-greenland-ice-sheet-melting-arctic-algae/
Is it because of algae and lowwer albedo? Any impact of delayed mechanisms, sea currents maybe?
scaddenp at 12:09 PM on 7 November, 2018

The ice-free part of greenland is only the southern/south-western edge which happens to be on edge of the North Atlantic "cold-blob" (see here for maps and further discussion of cold-blob). On the other hand, the ice-covered part of Greenland continues to warm and shed ice. Your reference was about the observations on the ice-free part.
MA Rodger at 23:50 PM on 7 November, 2018

Sarmata @23,
Your question is a little silly as there cannot be less ice if the analysis is conducted across "ice-free Greenland" and the annual average trend in Land Surface Temperature (LST) presented by Westergaard-Nielsen, et al (2018) is not "overall cooling" but overall warming through the period 1986-2016. The latter half of the period (2001-15) shows neither warming nor cooling at an annual level but does show a warming trend through summer (July) and a cooling trend through autumn (Sept-Dec), a situation which could still result in increased ice melt (if there were any ice to melt). The paper specifically proposes a link between the rate of ice-free Greenland LST warming and the Greenland Blocking Index (rather than the "cold blob" suggested by scaddenp @24).