The recently published paper A Topographically Controlled Tipping Point for Complete Greenland Ice Sheet Melt by Petrini et al. is a textbook example of how climate modeling has transformed from a scientific tool into a mechanism for manufacturing hysteria. Rather than producing objective assessments of future possibilities, this paper constructs a doomsday scenario with all the precision of a weather forecast 10,000 years into the future—making sure to terrify the public just enough to ensure continued research funding and political influence.
Abstract
A major impact of anthropogenic climate change is the crossing of tipping points, which may have severe consequences such as the complete mass loss of the Greenland ice sheet (GrIS). At present, the GrIS is losing mass at an accelerated rate, largely due to a steep decrease in its surface mass balance (SMB; the balance between snow accumulation and surface ablation from melt and associated runoff). Previous work on the magnitude and nature of a threshold for GrIS complete melt remains controversial. Here, we explore a potential SMB threshold for complete melt of the GrIS; the impact and interplay of surface melt and glacial isostatic adjustment (GIA) in determining this threshold; and whether the GrIS exhibits characteristics commonly associated with tipping points, such as sensitivity to external forcing. To this end, we force the Community Ice Sheet Model v.2 (CISM2) by cycling different SMB climatologies previously calculated at multiple elevation classes with the Community Earth System Model v.2 (CESM2) in a two-way coupled CESM2–CISM2 transient simulation of the global climate and GrIS under high CO2 forcing. The SMB calculation in CESM2 has been evaluated with contemporary observations and high-resolution modelling and includes an advanced representation of surface melt and snow–firn processes.
We find a positive SMB threshold for complete GrIS melt of 230 ± 84 Gt yr−1, corresponding to a 60 % decrease in SMB and to a global mean warming of +3.4 K compared to pre-industrial CESM2–CISM2 simulated values. In our simulations, a small change in the initial SMB forcing (from 255 to 230 Gt yr−1) and global mean warming above pre-industrial levels (from +3.2 to +3.4 K) causes an abrupt change in the GrIS final volume (from 50 % mass to nearly complete deglaciation). This nonlinear behaviour is caused by the SMB–elevation feedback, which responds to changes in surface topography due to surface melt and GIA. The GrIS tips from ∼ 50 % mass towards nearly complete melt when the impact of melt-induced surface lowering outweighs that of GIA-induced bedrock uplift and the (initially positive) SMB becomes and remains negative for at least a few thousand years. We also find that the GrIS tips towards nearly complete melt when the ice margin in the central west unpins from a coastal region with high topography and SMB. We show that if we keep the SMB fixed (i.e. no SMB–elevation feedback) in this relatively confined region, the ice sheet retreat is halted and nearly complete GrIS melt is prevented even though the initial SMB forcing is past the threshold. Based on the minimum GrIS configuration in previous paleo-ice-sheet modelling studies, we suggest that the surface topography in the central west might have played a role in preventing larger GrIS loss during the last interglacial period ∼ 130–115 kyr BP.
https://tc.copernicus.org/articles/19/63/2025/
At its core, the study uses computer models—specifically, the Community Ice Sheet Model (CISM2) coupled with the Community Earth System Model (CESM2)—to simulate the potential melting of the Greenland Ice Sheet (GrIS) under “high CO₂ forcing” conditions. The authors claim that a small shift in surface mass balance (SMB) can trigger “nearly complete deglaciation” of Greenland, a scenario that supposedly kicks in at a global mean warming of just +3.4°C above pre-industrial levels. They argue that the ice sheet is precariously balanced and susceptible to a so-called “tipping point,” where melt-induced surface lowering and glacial isostatic adjustment (GIA) would ensure its near-total collapse.
But here’s the problem: This scenario is entirely model-driven, with little to no real-world validation. And, more importantly, it hinges on assumptions that stretch the limits of scientific credibility.
Let’s first address the elephant in the room: The models. Climate models have long been notorious for over-predicting warming and ice loss. The CESM2 model used in this study is based on a set of emissions scenarios that often bear little resemblance to reality. Many climate fearmongers rely on Representative Concentration Pathway 8.5 (RCP8.5) or its newer equivalent, which assumes an implausible, nearly exponential rise in CO₂ emissions. The authors use the phrase “high CO₂ forcing” without specifying exactly which emissions scenario they are relying on, which is a red flag. If they are using a worst-case emissions scenario (which is common in these kinds of papers), then the entire study is essentially a speculative thought experiment rather than serious scientific inquiry.
Additionally, their model hinges on precise thresholds for ice sheet collapse, where a shift in SMB from 255 to 230 Gt/yr supposedly tips the entire Greenland Ice Sheet into a death spiral. This type of binary “all-or-nothing” thinking is a hallmark of alarmist climate science—where gradual, complex processes are reduced to dramatic tipping points that conveniently align with political talking points.
The timing of this paper is particularly interesting. With growing skepticism toward extreme climate policies, alarmist scientists and policymakers need fresh headlines to keep the public anxious. The message embedded in this study is clear: Act now or face an ice sheet apocalypse.
The funding mechanisms behind this research must also be scrutinized. Scientists who predict moderate, manageable climate outcomes rarely get their work amplified by the media or rewarded with large grants. But those who conjure up worst-case scenarios? They’re invited to speak at global summits, write op-eds in major newspapers, and shape government policy.
It’s a well-known trick: Use models to create a frightening future scenario, generate media buzz, and pressure policymakers into adopting economically disastrous “green” policies, all while ensuring the continued flow of research funding.
While Greenland has experienced ice loss in recent decades, its ice sheet is nowhere near a “tipping point.” Studies based on real-world observations—not just computer simulations—show that Greenland’s ice mass fluctuates naturally, with periods of melt and growth. During the Holocene Thermal Maximum (roughly 8,000 to 5,000 years ago), temperatures in Greenland were significantly warmer than today, yet the ice sheet remained intact.
Moreover, the study acknowledges that certain geographical features have historically prevented large-scale ice loss, such as the high topography in Greenland’s central west region. This means that even under extreme warming scenarios, a total collapse of the ice sheet is unlikely.
This paper is yet another example of how climate science has been hijacked by a political agenda. Instead of providing a balanced analysis of Greenland’s future, it cherry-picks an extreme scenario and markets it as inevitable. Worse still, it provides policymakers and activists with ammunition to justify economically crippling regulations based on speculative, unverifiable computer models.
The bottom line? The Greenland Ice Sheet is not on the brink of collapse, and no amount of fearmongering can change that. But as long as there’s funding and media attention to be gained from doomsday predictions, expect more of the same.
HT/Chris Martz
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Models, models, all the way down!
Adults who never played on a teeter totter as children don’t really understand tipping points. Like just about everywhere, Greenland’s climate oscillates.
But will it tip over, like Guam?
All climate models use bad internal physics which will never be able to tell us anything about the future. Doesn’t make any difference what scenario they are using. It’s even worse than GIGO, it is scientific malfeasance.
All models say what they are told to say.
Bingo!
If you tell the models to pout, they pout. If you tell the models to wiggle, they wiggle. If you tell the models to leave the stage because they’re not scary enough, they leave the stage.
Wonder how they are ignoring the INCREASING snowpack at the Summit which is gaining elevation in the last decade.
Mr. tommy: [sarc i promise] Wasn’t “increasing summit snowpack” predicted by AGW?
Are they calculating the volume or the weight? If they are deriving the weight from the volume they must take into account the density increase as the ice melts and refreezes. Snow is much lighter than ice therefore the weight could be going up while the volume is going down.
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Since l have started keeping my own records of temps. Am beginning to understand why the climate models are running warm. Because of the high sensitivity of modern electronic thermometers they are recording higher daytime temps then LIG thermometers under certain weather conditions
My own results have shown here in England, that the difference between electronic thermometers in small screens and my LIG thermometers in open shade can be as much as 2C higher on sunny winter days in calm weather conditions.
This has got to be impacting on the data been collected for the running of these climate models.
What He measured back in 1995
Interviewed was meteorologist Klaus Hager. He was active in meteorology for 44 years and now has been a lecturer at the University of Augsburg almost 10 years. He is considered an expert in weather instrumentation and measurement. One reason for the perceived warming, Hager says, is traced back to a change in measurement instrumentation. He says glass thermometers were was replaced by much more sensitive electronic instruments in 1995. Hager tells the SZ ” For eight years I conducted parallel measurements at Lechfeld. The result was that compared to the glass thermometers, the electronic thermometers showed on average a temperature that was 0.9°C warmer. Thus we are comparing – even though we are measuring the temperature here – apples and oranges. No one is told that.” Hager confirms to the AZ that the higher temperatures are indeed an artifact of the new instruments.
http://notrickszone.com/2015/01/12/university-of-augsburg-44-year-veteran-meteorologist-calls-climate-protection-ridiculous-a-deception/
It’s not only the sensitivity of the instruments but also the amounts of measurements compared to old style thermometer readings. It is continuous. That has also an effect on registering peaks..
“But as long as there’s funding” shouldn’t be an issue for much longer. Hopefully Musk will deal with that nonsense as quickly as he’s dealt with USAID grants.
OK, Greenland melts. So what?
There is coastal flooding? Sure. What are we going to do about it?
Abandon technology and pray for the best? Maybe along with sacrificing virgins? If we can find any?
More likely we would move to higher ground.
Oh yes, and Bangladesh will suffer catastrophically. Thus showing that anything that happens anywhere to anybody under any circumstance.will cause catastrophic suffering in Bangladesh
Except that Bangladesh is getting larger
And higher.
The models are the new tarot deck.
Forecasts are much like horoscopes – sunny spells and showers…
That is an insult to tarot cards and to astrologers.
They deserve to be insulted.
“A major impact of anthropogenic climate change is the crossing of tipping points, ..”
That makes no sense to me and likely makes no sense to the person that wrote it. I think booze was involved.
You mean he meant “tippling points”. 😉
“A major impact of anthropogenic climate change is the opportunity for doomsayers to screech, “Ahhh. . . Everything is bad and getting worse! And now we’re all gonna die!”
And then they tip a drink.
A series on Hulu called Paradise is predicated on this idea. Man causes ice reduction in Antarctica. A volcano explodes causing a huge tsunami. Tsunami causes countries to launch nuclear weapons. Most people are wiped out except for the 15000 kept alive in a bunker in Colorado.
To paraphrase Gershwin, “But who calls that livin’ if no gal will giv’in to no man who is bunkered in Colorado?”
Here is a clue, Greenland is still covered in ice/snow, there is nothing in the foreseeable future short of an asteroid strike that is going to change that.
Yet to come – the anthropogenic fearmongering
Mr. various: Yeah, I used to have a heat pump, the cold spot was the entire inside.
FWIW the paper says: ‘In this simulation, atmospheric CO2 concentration is increased by 1 % every year until it reaches 4 times pre-industrial values at year 140, after which it is kept fixed.’ This roughly corresponds to SSP5-8.5.
I went to this page
And not one GCMs even gets a mention !!
Tony Heller provides all the data that shows what a load of total bollocks this is.
Greenland About To Collapse | Real Climate Science
Not to mention that Greenland ice area is only a nudge down from its peak during the LIA, and much more than for most of the Holocene.
(note, graph counts the archipelago area as well as the mainland )
A fake copy of Briner’s graph, in particular the addition in red which purports to show time up to 2015 whereas in fact there is no data more recent than 1950. You should take anything Heller says with a pinch of salt, does he still believe that CO2 freezes on the South Pole?
There has been basically no decline in area since 1950, so that part of your comment is meaningless.
There is nothing fake about the graph, just notation added so people with near zero knowledge can get a better understanding.
Tony Heller has many time the knowledge that you have.
“Tony Heller has many time the knowledge that you have.”
Hardly, as he proved in the discussion where he claimed CO2 froze at the South Pole and demonstrated his complete lack of knowledge on the CO2 phase diagram. He’s not posted here since that debacle.
“There is nothing fake about the graph, just notation added so people with near zero knowledge can get a better understanding.”
Trouble is, that notation is false as I pointed out!
Current Greenland Ice Sheet area is 1.7 on that scale, i.e. well below that graph. The excuse being that it includes the archipelago as well as Greenland. As can be seen in the attached satellite image there is no longer significant ice sheet there!
OMG, you still don’t understand that Briner counted the archipelago region as well. LOL !!
As shown there is no significant ice sheet in the archipelago, certainly not 0.2×10^12m^2. The ice on Baffin Island has shrunk by over 50% in the last 50 years and is continuing to recede, uncovering land that had been ice covered for ~40,000yrs! The ice on Ellesmere has also been substantially diminishing this century.
Oh and thanks for posting a map that shows MORE ice cover than Briner’s map does. 🙂
Note that Briner’s chart above match GISP et etc, which shows most of the Holocene to be much warmer in Greenland.
Also matches all the Arctic sea ice proxy evidence showing there was much LESS sea ice than now, for most of the Holocene.
The fact that Greenland was warm enough in the past to be farmed without the rest of the planet falling apart tells us everything we need to know!
A “Tipping Point” implies to me a point of no return, as when a tree or rock spire falls over. There is good evidence from the CRREL drilling program in 1966 that during the Eemian, most, if not all the Greenland ice melted for long enough to establish vegetation on the ground. Yet, the ice has returned, demonstrating that the changes are periodic and not actual Tipping Points. Talking about Tipping Points is scaremongering.
Greenland is gaining elevation at 17mm per year according to NASA and the ice cover extent is trending toward full permanent cover by 2075 as evidenced by the Jacobshacvn glacier on the western side advancing and thickening.
400ka, Greenland was close to ice free with sea levels 10m higher than present. Then the precession cycle began increasing the solar intensity in the NH and the sea level dropped dramatically over the next 10kyr:
?ssl=1
The solar intensity in the NH reached its minimum in the present precession cycle in 1582. It has been increasing since. That is causing the oceans in the NH to warm; causing more moisture in the atmosphere; resulting in higher snowfall with new snowfall records now being a common occurrence and snowfall is already overtaking snowmelt on the summer and the western side of Greenland.
Climate models are blind to the precession cycle so are incapable of producing glacials and interglacials.
Sorry to bore everyone again but the Danish government website records “Arctic (ie 80 north to pole) temperatures’ every year since 1958 and this shows consistently that there’s a melt to say 1.5degsC for about four weeks in July Aug with freezing otherwise. Absolutely consistent. Look it up. So can’t see any sudden increase in Greenland melting outside the variations that seen in the GMB graphs. Relax
Do we need to look at the amount of heat that is available to melt the ice sheet? The mass of the Greenland ice sheet is about half that of the atmosphere; the specific heat capacity of ice is twice that of air. So the thermal mass is about the same. So if we could somehow extract all the extra heat that has appeared in the atmosphere over the last 175 years and which has caused the atmosphere to rise by between 1 and 1.5 degC and put it into the Greenland ice sheet, it would warm it by about the same. So it would go from about -30 degC (is this right?) to -28.5 degC. Assuming the amount of heat in the oceans has increased 20 times that of the air, if we extracted all the heat from the air and oceans and somehow pumped it into the Greenland ice sheet, it would take to maybe 0degC. The latent heat of ice to water is 334 so we would need to find another 16 times the total extra heat in the globe to melt the ice sheet.
This is a simple heat model. Is it true?
Close enough. The glacier calving off the Southeast coast of Greenland cools the Gulf Stream and sends a plume of icy water northward on the current- per attached.
Interglacials occur when the ice carrying capacity of the land in the NH reaches a point where glacier calving and icebergs cool the ocean to lower atmospheric moisture to the point when snowfall loses out to snow melt and the rising sea level causes a cascading failure of ice shelves that cool the ocean surface even more. The recovery is usually over inside 10,000 years with sea level rise reaching 70mm/yr while the descent has been longer than 100 years with maximum fall in sea level no more than 30mm/yr but interspersed with long periods of little or no decline; even slight rebound….
More trash from the CAGW clowns.
I’d like to see a day pass when at least one climate alarmist source isn’t warning us about one environmental tipping point or another. If it’s not temperatures, it’s precipitation, drought, violent storms, sea level rise, melting icebergs, habitat loss, species decline—you name it. And all of them are just excuses for governments to impose new taxes, laws, restrictions and mandates—to save the planet, of course.
Remember George Carlin’s routine that ended something like “Save the planet!?!?!?!? The planet doesn’t need saving. Some people are (beep) but the planet’s doin’ just fine.”
Speaking of unscientific studies about the Greenland Ice Sheet, here’s one I conducted with help from Copilot AI
Significantly abbreviated first attempt labeled too long by WUWT
Question: A WWII P-38 plane was recently found buried under 300 feet of packed snow/ice in Greenland that had accumulated over the previous 75 years. That’s an average of 4 feet per year. Is that a good rule of thumb for continental Greenland snow/ice accumulation?
Greenland’s ice sheet is vast and spans different climatic zones, so accumulation rates can differ widely. Coastal areas, for instance, might have different rates compared to the interior of the ice sheet. Additionally, factors such as annual temperature variations, snowfall, and local weather patterns can influence the rate of accumulation.
Question: Could we break the “zones” down to about 16 equalized sized zones and average them
Each of these zones has unique climatic conditions and can have differing rates of snow and ice accumulation. To get an average accumulation for each zone, we could look at historical data, weather patterns, and specific studies conducted in those regions.
Would you like to explore data for any particular zone or delve deeper into a specific region’s accumulation trends?
Comment: Excellent can you quantify those into numbers, plus minus 25% would be fine
Sure! Here’s a rough estimate of the snow and ice accumulation rates for each zone in Greenland, with a ±25% margin:
These numbers are based on general trends and available data2. Keep in mind that actual accumulation rates can vary due to local climatic conditions and annual weather patterns.
So, the average snow and ice accumulation rate across these 16 zones in Greenland is approximately 431 mm per year
.
Question: How many tons per year does that 431 mm weigh based on the area of Greenland
To calculate the total weight of the snow and ice accumulation on Greenland, we need to consider the area of Greenland and the density of the accumulated snow and ice.
So, the total weight of the snow and ice accumulation on Greenland is approximately 858,862,320,000 metric tons per year.
Question: How much is lost to calving per year averaged over the last 20 years
Over the past 20 years, Greenland has lost an average of approximately 270 gigatons (Gt) of ice per year due to calving and surface melting2.
Comment: Therefore accumulation over the past 20 years is approximately twice what is lost to calving.
Answer: However, keep in mind that this is a simplified view. The actual dynamics of Greenland’s ice sheet are far more complex. Factors like surface melting, subglacial melting, and variations in snowfall can affect the net gain or loss of ice. Recent studies indicate that Greenland’s ice sheet is currently losing mass overall due to climate change….
“A WWII P-38 plane was recently found buried under 300 feet of packed snow/ice in Greenland that had accumulated over the previous 75 years. That’s an average of 4 feet per year.”
It also had drifted a couple of miles towards the sea, in 50 years, that’s about 30m/yr.