Charles Rotter
A new paper, A recent stabilization in the lengthening of the Arctic sea ice melt season into a highly variable regime, from NASA Goddard and the University of Maryland, published in Communications Earth & Environment, reports that the Arctic sea ice melt season stopped getting longer around 2010. For the fourteen years from 2010 through 2023, it actually got slightly shorter.
From the abstract:
However, since 2010 the melt season length has stabilized (~ 108 days), showing no consistent change over the years, instead becoming highly variable (+/− 11 days), largely driven by a loss of multi-year ice in 2000–2009 and a small change in the freeze onset (~ 2 days). There is a stark difference between the decades, where the largest changes in the melt season occurred between 2000–2009 (+ 25 days) and the smallest occurred between 2010–2023 (−2 days).
Here is their chart of it, with a spelling error:
The melt season grew by about 40 days from 1979 to 2023, and most of that came in a single decade, 2000–2009, the blue line. The purple 2010s bounce around and go nowhere. There is no trend line on them because there’s no trend. Table 1 of the paper labels 2010–2023 the “Stabilized Era.”
Here is the next sentence of the abstract:
This leads us to believe that, while there might be some periodicity in the processes that control the decadal variations in the melt season length, anthropogenic forcing has altered the Arctic background state and led to a new Arctic melt season that is much longer with a much thinner ice pack that is more susceptible to external forcings.
“Leads us to believe.” Nothing in the paper tests anthropogenic forcing. There is no model run, no attribution analysis, no forcing dataset. When the authors go looking for what drove the changes, they find clouds:
Between 2000–2009 there was a large increase in net shortwave (SW) radiation (+ 12.6 Wm−2) and therefore the SEB (+ 10 W m−2, driven by decreasing surface albedo (−0.022%) and cloud cover (−2.3%)). During 2010–2023, an increase in cloud cover (+ 7.2%) and only minimal changes in albedo (0.011%) drove a net decrease in SW (−3.14 Wm−2) and summer SEB (−2 W m−2).
And what moved the clouds:
The significant decrease in cloud cover in the Chukchi and Beaufort seas and the Canadian Archipelago (western basins) with increasing cloud cover in the Barents Sea (and other eastern basins) reflects a positive AD in 2000–2009 (Fig. 7h).
This is starkly contrasted with significantly increasing cloud coverage in the Chukchi and Beaufort seas, the Canadian Archipelago, Central Arctic and E. Greenland Sea (western basins) in 2010–2023 but declining cloud cover over the Barents, Kara, and E. Siberian Seas (eastern basins) (Fig. 7l), corresponding to a negative AD.
AD is the Arctic Dipole, a pressure pattern that is part of the Arctic’s natural circulation. Compare the middle map with the right one. The same stretch of the western Arctic clears out in 2000–2009 and clouds up in 2010–2023. A positive Dipole let in more sun during the decade of rapid lengthening, and a negative Dipole brought the clouds back. The energy reaching the surface followed:
Hatching marks significant trends. Fig. 6a, e, i from Boisvert et al. 2026. Only a few small patches there are hatched as significant, and they’re outnumbered by the hatched blue elsewhere on the same map
So did the ice:
Whereas in 2010–2023, there is an overall decrease in the ROC of net daily SEB energy entering the system (−1.26 W m−2), which could result in a growth of up to 7 cm of ice over the 14 years. Indeed, CryoSat-2 observations suggest that there were areas with slight thickening of the ice in October/November over this decade (3.3 cm average increase in October/November SIT in CryoSat-2 over the record (2011–2021))
So the stall goes down as internal variability, and the lengthening before it goes down as a changed background state caused by people. Clouds moved around by the Dipole explain both decades in the paper’s own analysis, but only the earlier one gets the anthropogenic label.
The paper ends on the one place it could find going the other way, and the authors concede the overall decline in the same breath:
Despite the overall net JJAS SEB decrease in 2010–2023, there is a notable increase of summer net JJAS SEB over portions of the Central Arctic where the remaining MYI resides (Fig. 6i). Between 2010 and 2023, the sea ice in the Central Arctic has received roughly +0.5 W m−2 more energy per year (~ 7 W m−2 overall). This energy could melt ~18.4 cm more ice by the end of the record, significantly thinning and weakening the MYI SIT in this area (Fig. S3l). With this increase in energy, this extra JJAS net SEB energy has the potential to melt 6% of the thickest sea ice north of Greenland, which averages around 3 m. Crucially, if this trend continues and exceeds winter regrowth, the MYI could become thin enough to be vulnerable to melt out in the future, resulting in an ice-free Arctic in the summer.
That is panel i of the energy maps above. Look north of Greenland. The orange there is pale and patchy and carries little of the hatching that marks a significant trend. From that, plus an “if this trend continues,” they get to an ice-free summer.
The introduction does its part before the reader reaches any data. It brings in Arctic warming at nearly four times the global rate, ice-free summers projected for the 2030s to 2060s, bigger ocean swells, coastal erosion, seal reproduction and polar bear predation, and the jet stream. The paper looks at none of it. “Imperative” shows up three times.
Then there is the proofreading. The paper was received in May 2025 and accepted in April 2026, and nobody caught the following. The abstract and Table 1 put the stabilized melt season at about 108 days. The Results section says:
In the last decade, however, the later melt onset together with the large interannual variability in both the melt and freeze onset led to a stabilization of the Arctic melt season to an average ~120 days.
The abstract gives the albedo changes as −0.022% and 0.011%. The paper’s own albedo maps in Fig. 6 are labeled in fraction per year, which makes the abstract off by a factor of a hundred. The standard deviation is said to rise to “10.6 days in 2010–2013.” The headline chart is titled “Melt Seaon Length.” Table 1 defines the Arctic Ocean as regions 9–13 and 15, Table 2 uses 9–15 excluding 14, and the Methods say:
The Arctic Ocean region defined in this study comprises regions 2–15 defined in Fig. 1a.
None of this overturns the result, but a summary going out to the press ought to get its own numbers straight.
If less clouds under a positive Arctic Dipole drove the 2000s lengthening, where does anthropogenic forcing enter the calculation?
Why is the 2010–2023 stall internal variability while the 2000–2009 jump is a new background state?
If summer energy went down over the Arctic Ocean, why end the paper on the one area where it went up?
And is the stabilized melt season 108 days or 120?
==========================================================
Quotes and figures from Boisvert et al. 2026, https://doi.org/10.1038/s43247-026-03534-8, used under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). Figures cropped from the originals.
I did some brief research on the Arctic Dipole. I see that NASA and some other sites say the changes are caused by natural forces AND anthropogenic warming. I found this little jewel.
Somehow water vapor in the tropics enhances the loss of heat, I don’t know how since it supposedly works like CO2 in delaying or trapping heat, yet where there is no water vapor, as in the Arctic, radiation somehow doesn’t go directly to space. One would think that CO2 has a more drastic effect in the Arctic. Hmmm!
Whenever a time-series chart is posted to WUWT, the usual suspects crawl out of the woodwork to demonstrate their intellectual prowess.
‘A new paper…’
I was gonna say “put the crayons down, fellas”, but there weren’t any among the paper’s authors.
What on earth does the author’s gender have to do with the quality of the paper?
Judith Curry,
Katherine Johnson,
Dorothy Vaughan,
Mary Jackson,
JoAnn Morgan,
Frances Northcutt,
Margaret Hamilton,
Maria Curie,
and many, many more
“fellas” in the context of English is gender neutral as there is no context in the subject that defines it as gender masculine. People have lost the nuances I learned as a kid.
Fair enough, although not really a phrase we use here in Blighty (or at least not in my neck of the woods)
Has this study been approved by Ripley’s?
I have yet to read the authors’ entries in Who’s Nobody
Melt season length and total melt are different things.
Arctic sea ice melt season may not have gotten longer between 2010 and 2023, but annual Arctic sea ice extent continued to decline over that period (-0.18 m/km2/dec).
You would need to show the statistics that produced that line because even by eye a flat line thru 10.5 would be valid for that data. The line that is shown would have a confidence level of about 50%, pretty much a coin toss on that or a flat line. I really hate bullshit graphs.
He’s referring to annual sea ice extent, which of course is different to the number of days of melt. Taking a close look at the NSIDC website, 2026 is currently very close to record low annual sea ice extent for this stage in the year. It has however, managed something of a recovery over the past couple of months. Up until August, 2026 was on target to break the record for minimum annual sea ice extent.
Follow the link in the above post, or here.
It is NOAA sea ice extent data. The graph was produced in Excel using that NOAA data and the red trend-line is the linear trend, produced using Excel’s LINEST function.
The Final Corrosion of the Nail
Another failure to respond from the busted strings
Wonder if you’re scared of your own shadow, too.
By Mark I eyeball estimate, the average over the period is about 10.5 mkm2. The max/min range is about 0.24 mkm2. The sea ice extent varies about 1.1% or so around the average. Your stupid graph might scare you and your buddies, but no one else.
Not trying to scare anyone (sorry if you were scared – sounds like it).
Just using the NOAA data to show that the sea ice extent has continued to reduce, despite the reduction in the length of the ice melt season.
You are free to follow the links, download the data and check it for yourself.
Do not fear.
Deep down, they’re afraid of AGW.
Deep down, you are wet.
why on Earth would anyone be afraid of a few tenths of a degree of warming?
It’s way more than a few tenths of a degree at this point:
“Timely and accurate projections of when global warming will exceed the Paris Agreement’s 1.5 °C threshold are essential for effective climate policy. Existing estimates place this exceedance in the early 2030 s but carry substantial uncertainty. Here we analyze the latest observational temperature records through 2025 and identify a statistically significant doubling of the global warming rate during 2011–2025 (0.40 °C per decade) compared to 1971–2025 (0.20 °C per decade). Extrapolating this accelerated rate projects a crossing of the 1.5 °C threshold by 2028, nearly a decade earlier than previous estimates. Regional analyses attribute this acceleration primarily to intensified warming over East Asia–the North Pacific, mid-latitude Eurasia, and the South Atlantic–Antarctic regions. The ensemble mean of 26 climate models fails to capture the observed doubling of the warming rate, simulating a rate of only 0.29 °C per decade. These findings suggest a narrower window remains to limit warming to 1.5 °C, underscoring the urgency for rapid and substantial reductions in greenhouse gas emissions.”
https://www.nature.com/articles/s41612-026-01561-y
If you believe anything from Nature website you have been brainwashed.
Ok. Do you believe UAH?
Using the UAH Global temperature dataset—this site’s preferred dataset—the warming rate from January 2011 through December 2025 is +0.42°C/decade, consistent with the findings of the study published in Nature.
I did not participate in any agreement to limit use of fossil fuel at any time anywhere because, Net Zero is based upon a false premise.
Rates of warming of the overall climate on a long scale have not relationship to very short scale changes.
The very slow, decelerating of the natural warming due to the current GSM, the solar magnetic field minimum allowing cloud nucleation increase is operating.
No human activity involved.
Therefore while I live I will campaign against Net Zero and vote against every candidate for office which supports it; and I will encourage my large extended family and friendship group to do the same.
“Therefore while I live I will campaign against Net Zero and vote against every candidate for office which supports it; and I will encourage my large extended family and friendship group to do the same.”
Well, at least the planet had a good run.
Mr. whatever: Uh huh, and you say WE are the ones in fear??!! Projection, again.
This is just silly. Comparing a 14-year trend to a 54-year trend is nonsensical. A valid comparison can only be drawn if the trends for equal lengths of time are compared. We know the temperatures (granting, for the sake of argument, that a global average temperature is meaningful) decreased until about 1979, so that will obviously skew the earlier period down. There was also a plateau from 1998 to 2006, so having an increase after that is not surprising, assuming an underlying warming trend, regardless of cause. Finally, the 1.5 degree threshold can only be reached if a 30-year average of that anomaly value has been calculated, so assigning the “breach” to a single year or even decade cannot be done, based on the conventional definition of climate
Deep down we all know that AGW is a lie perpetrated by those who want to control our lives and supported by “scientists” who are bought and paid for by those same groups (governments and NGOs).
And there’s a big invisible foot trying to stomp on us, too. WHOAA!
I actually tried to run the csv files in your link but you need to make choices. There are fields that have -9999 which and 1978 only has Nov and Dec and 2026 only has 9 months so far. I am guessing to get an average they add each month and divide by twelve but that is dangerous because there are trends in each month, you basically end up with a mess.
For example the minimum extent falls in September in all 48 years from 1979 to 2026. That at least gives sample confidence so If you analyze that month
Results
September Measure Value Mean (1979–2026)5.85 M km²
Record low3.57 M km² in 2012
Highest7.67 M km² in 1980
Linear trend−0.74 M km²/decade (95% CI −0.85 to −0.63)
R² / p-value0.80 / ~1.5×10⁻¹⁷
Trend relative to 1981–2010 mean (6.41)about −11.6% per decade
Fitted change 1979 → 20267.59 → 4.11 M km² (about −46%)
DecadeMean (M km²)1980s7.211990s6.662000s5.652010s4.662020–264.59
The decline has not been a steady line
So that is a bit all over the shop itself and that is the best of the data.
They’re just monthly average sea ice extent data files.
You’re talking about September extent data, which is something you have introduced and which is neither the subject either of the initial post or of my response.
Hence your confusion.
You don’t want to discuss that fine then you analysis you post is garbage because of how they are treating the data. It is the equivalent of each family having 2.2 children. It may be true but it’s useless.
And this is winter Arctic sea ice extent, which shows a declining trend of −4.23 × 10^5 km^2/decade:
No stabilization since 2010.
Arctic sea ice loss continues.
Winter sea ice extent is certainly on the decline. The last couple of winters, in particular have seen a very early plateau of sea ice growth.
Mr. rosion: When you see trees growing near the ancient stumps that emerge from this slight warming, let us know. Bet the natives up there would just hate to see trees growing, eh?
Be unusual for tree stumps to emerge from sea ice but you never know.
The Arctic is more than sea ice. Warmth in the Arctic and melting glaciers uncovering trees give a good indication that the atmospheric temperature has been warmer.
Indeed it was Jim.
Caused by the Earth’s orbital eccentricity, that meant that high latitudes received very much more insolation than now ……
Of course this is just a basic and of which you should know.
Your graph is misleading.
480 × sin (25) = 203 W/m² –> 244K = -29°C
530 × sin (25) = 224 W/m² –> 251K = -22°C
I don’t think atmospheric temperature is driving anything even at 100% CO2.
Ocean currents have more to do with Arctic heat and glaciers, which you should know.
And, if you don’t believe sin(25), here is an image from a meteorological textbook, Practical Meteorology, Dr. Ronald Stull.
“I don’t think atmospheric temperature is driving anything even at 100% CO2.”
And what, pray, has that got to do with the fact that when the Sun is higher in the sky in summer then, err, it’s hotter?
Nor is you your lesson in trig “driving” anything – rather it is your usual of obscuration via over complication.
OMG! What angle do *YOU* think is appropriate?
The assumption is that the sun follows the equator – THUS PROVIDING AN ESTIMATE. If you want to work out the angle for “summer” vs “winter”, then have at it. It is *still* going to be sin(θ) whether θ is 25deg, 24deg, or 26deg!
Having been involved in RADAR, a factor mission is when there is a non normal angle of incidence, the magnitude of reflected EM increases.
Aside from the accurate description of the angle, there is a second factor that further reduces the W/m^2. The latitude circumference of the planet is smaller at higher latitudes. This also narrows the area the TOA irradiance inputs the ground.
Another piece missing is the optical depth at the atmosphere is defined by a spherical shell. At higher latitudes, the optical depth is greater simply due to geometry.
Agreed.
Mr. Nail: I thought AGW was causing sea levels to rise, no? When the sea rises, where does it go? Onto land that used to have trees, perhaps?
You seem to show your profound ignorance just when you think you’re scoring.
“Bet the natives up there would just hate to see trees growing, eh?”
Maybe. As mentioned below, Indigenous Arctic communities have expressed considerable distress over the consequences of Arctic warming.
None that I have seen reported.
Notice that is “DJF mean” … That is Dec Jan Feb Mean.
So someone cherry picked 3 random months because that tells the best story. The data is all over the shop and you could make any story you want out of it. Do you want me to find three months that tell the worst story for sea ice decline?
If you believe your data sea ice will be gone by 2042 or there abouts … want a bet on that?
We don’t even have to wait that long because September is the lowest month (September Measure Value Mean (1979–2026)5.85 M km²) you should start seeing zeros or ice free by mid 2030s which you must believe.
All I am seeing is idiots cherry picking data.
Deniers think meteorological winter is a randomly selected set of 3 months.
So September data, as used by NOAA is an anomaly? Got it.
So you can’t argue using facts and science you resort to name calling, so why are you even posting?
That by definition makes you nothing but a troll.
Mmmmm…
I see you posted this first;
“All I am seeing is idiots cherry picking data.”
Then Edrosion posted this:
“Deniers think meteorological winter is a randomly selected set of 3 months.
Yet you post this in response ….
” …. you resort to name calling, so why are you even posting?
That by definition makes you nothing but a troll.”
There’s a word for that kind of thing.
Hey I am still willing to discuss the data, but I don’t do STUPID discussions.
So lets say I buy Eldrosion analysis, a trend of −4.23 × 10^5 km^2/decade is =-0.423Mkm². It’s at 13Mkm² last reading so that is 13/0.423 = 30.7 decades. So we reach ice free in 307 years. Yeah they published it in scientific notation which means 10E5 not 10E6.
Given the minimum ice trend has somewhat flattened and we haven’t even seen an “ice free” minimum even at 5Mkm². For the 13Mkm² to get down to 5Mkm² it is going to take 8/0.423 = 18.9 decades = 189 years.
So even if I buy into the stupidity of a really dodgy statistics manipulation we are all going to be well an truely dead and worrying about it is a little bit over the top. The bottom line is they couldn’t even cherry pick data that was scary 🙂
“Hey I am still willing to discuss the data, but I don’t do STUPID discussions.”
Seems not – just like you *stupidly* evade the issue of being the first to use ad hom, while accusing another of using ad hom..
Like I said – there is a word for that.
We tend to attract our fair share of negative attention around here for simply posting facts, and honestly, we wouldn’t have it any other way — this place wouldn’t be nearly as fun without it!
He showed you his math and even used numbers. It is your turn to pony up and show your math and use numbers. Otherwise you are all blow and no go! All hat and no horse! Shall I go on?
“So lets say I buy Eldrosion analysis, a trend of −4.23 × 10^5 km^2/decade is =-0.423Mkm². It’s at 13Mkm² last reading so that is 13/0.423 = 30.7 decades. So we reach ice free in 307 years.”
307 years for an ice-free Arctic during winter? You realize that even during the Last Interglacial, when the Arctic experienced substantially warmer summers and potentially ice free summer conditions, winter sea ice still persisted?
The disappearance of Arctic winter sea ice during the current interglacial would represent an extraordinary climatic transformation, exceeding anything known to have occurred during prior interglacial periods.
“So even if I buy into the stupidity of a really dodgy statistics manipulation”
The irony is that you’re comparing winter and September sea ice extent while assuming the historical winter decline rate can be extrapolated unchanged for centuries.
As this very article illustrates, Arctic sea ice exhibits distinct seasonal behavior, and the processes governing its decline differ between summer and winter.
So you think it’s extraordinary doesn’t make it so, it’s 300 years away. Do you know the sun will eventually burn out go into a red giant explode and wipe out earth … that is a fact. If it isn’t that we will lose a battle to some microbe, AI a comet or some other disaster.
Our job as a species is to adapt survive and multiply whatever the universe throws at us. You may have all the best intentions in the world but the universe does not play nice and it will not stay stable not now not ever.
Everyone bar you activists have got better things to do for the rest of their life than worry about a very distant problem way beyond there lifespan and would require the world to sit down around a campfire and sing Kumbaya while drinking the cool-aide.
If you want to be accurate I am a realist and a pragmatist, i really don’t care what you believe or how you see the world.
““Deniers think meteorological winter is a randomly selected set of 3 months.”
This just demonstrates that erosion doesn’t understand that cold months, normally considered as WINTER months, are DIFFERENT in the northern and southern hemispheres!
Climate science and erosion ignores the fact that the variance of both the absolute temperatures and the variance of the anomalies are different during warm months and cold months. Climate science and erosion don’t do *any* weighting of the data based on different variances, they just jam it all together.
Just who is the denier here?
One genuinely wonders if an idiot like you will think it is “good news” when ice extent starts growing.
“Climate change is not only affecting the health of many Arctic species—it is also having an impact on the people and communities that depend on them to survive. A new study shows that a decline in sea ice has severely curtailed the length of the seal-hunting season in northern Alaska, threatening the communities that have depended on these marine mammals for food and clothing for generations.”
https://www.arcticwwf.org/the-circle/stories/retreating-sea-ice-threatens-indigenous-way-of-life/
Nothing is guaranteed in this life. If you think the Arctic has never had low ice coverage, you need to study somemore.
A careless reading of the above article might easily cause the unwary (such as your good self, ‘AGW is Not Science’), to stumble to the conclusion that just because the start and end dates of the melt season in the Arctic stabilised for a few years, it must follow that the melt itself has therefore also reduced.
A brief examination of the sea ice extent data, to which the above article fails to provide a link, confirms the opposite: despite a stabilisation in the duration of the melt season, the total ice melt by extent has continued to decline in line with the long-term decreasing trend. Another fact not mentioned in the above article.
The headline could equally be: “Arctic Sea Ice Extent Continues to Decline Despite reduction in Melt Season Duration”.
But that’s not the sort of look we like to see here at WUWT, is it?
To assume that sea ice coverage is due to CAGW and has never happened before. If you want to prove that you must prove that past low ice during this interglacial of 10,000 years was caused by something else. Good luck with that. Till then denigrating others that differ in opinion is the characteristic of a nitwit.
Red herring.
Melt season length and total melt are different things.
True.
However, it is a red herring to introduce total melt into a conversation about melt season length.
Given all things equal (they are not), a melt season stabilized will lead to a total melt achieving equilibrium. This is not instantaneous.
Maybe, this is a harbinger of the coming colder period of the 2030s and 40s, as the Melankovichs calender predicts!
What Melankovich calender predicts this, thanks?
Are you seriously telling us you have no knowledge or acquaintance with the current GRAND SOLAR MINIMUM presently manifested by the sun where much reduced solar magnetic shielding of earth from cosmic rays is allowing greater cloud formation thereby reflecting more energy out back out from the sun; the same conditions which were in effect during the Maunder Minimum, not a fantasy but a well documented cold period in the history of literate Northern Hemisphere civilisations,
Google Svensmark Zharkova GSM
I was asking about the “Melankovichs [sic] calender”, but thanks for changing the subject.
Err, no ……
To me, it looks like the melt season stopped getting longer in 2004.
Yeah, but you’re not a climastician. Climate science uses secret, specialized statistics unknown to the common scientist.
Climate people, I hesitate to call them “scientists,” real, honest, scientists always question, even their own opinions, these climate people have a list of the things they can get paid to promote and a list of things they will get punished for if they mention them in a good light.
I will gladly accept your correction. I probably should have put “climate science” in scare quotes. Reminds me of this little saying:
Climate is to science as witch is to doctor.
Again, let’s not confuse ‘duration of melt season’ with ‘observed melt’.
The latter is far more pertinent that the former.
I bet they’re correlated. You could probably make a graph and draw a line through it even.
Let’s pretend that the small variations matter to anyone.
I know this is a bit of a tangent to the mechanisms discussed here. But in any case a quick look at the monthly record of total ice area in the Arctic shows the September minimum to have sharply dropped in 2007 and has leveled out since then.
https://psl.noaa.gov/data/timeseries/monthly/data/n_icearea.mon.data
Was the prior slow decline leading to 2007 caused by anthropogenic emissions of CO2? No way to tell.
What was the cause of the deceleration of the area loss and the leveling out of the reported September ice area since then? Not anthropogenic – no plausible mechanism.
That is all for now.
Believe it or not…..
Can anyone envisage or even conceive of mad Ed Miliband ever approving drilling for oil??? Well, it’s a funny old world.
Britain cannot stop the Falkland Islands from developing oil resources because the territory governs its own natural resources and lies outside UK ministerial jurisdiction.
And so…
Miliband signs off on Falklands drilling
https://www.telegraph.co.uk/business/2026/10/13/miliband-signs-off-on-falklands-drilling/
Excellent, better than that bacon sarnie.
So Charles, I’m guessing that you don’t get tapped to be a peer reviewer of ‘consensus’ climate science very often?
🙂
Not only does the first graph in the above article, attributed to Boisvert et al. (from NASA Goddard and the University of Maryland, published in Communications Earth & Environment) contain a misspelling in its title, it also contains this sophomorically incorrect logic:
If one draws a fair trend line from 1989 to 2000 (slightly more than a decade) and another fairly-drawn trend line from 2005 to 2025 (nearly two decades), one can clearly see that the slope change in interval between the two occurs only over an interval of (2005-2000) = five years, NOT a decade.
There is absolutely no merit to comparing a parameter, such as Arctic melt season length in days, versus calendar decade.
Furthermore, IMHO, it is debatable that such a variation is even statistically significant, given the year-to-year maximum “noise level” (about 30 days max-to-min) is greater than the imputed change from 2000 to 2005 (about 106-87 = 19 days).
Bottom line: a worthless graphic.
It’s enough to convice the credulous like TFN, which is its purpose.
But it’s peer reviewed, so it must be correct.
It’s the sun.
No, it’s the moon.
Yes, M’lord.
“This energy could melt ~18.4 cm more ice by the end of the record, significantly thinning and weakening the MYI SIT in this area (Fig. S3l). With this increase in energy, this extra JJAS net SEB energy has the potential to melt 6% of the thickest sea ice north of Greenland, which averages around 3 m. Crucially, if this trend continues and exceeds winter regrowth, the MYI could become thin enough to be vulnerable to melt out in the future, resulting in an ice-free Arctic in the summer.”
This above is highly speculative. The upper Arctic shows no signs of warming, and in fact usually remains pretty close to 0c all summer – summer 2026 being probably record-breaking in terms of staying colder than average. Whatever the mechanism that causes this, latent heat etc, the loss of sea ice (or otherwise) in the upper Arctic remains very hit or miss at best.
“The upper Arctic shows no signs of warming, and in fact usually remains pretty close to 0c all summer”
The upper Arctic remains close to 0C in summer due the fact that it is either ice or water at a temperature of at or below 0C.
You cannot expect air flowing over that surface to get much beyond 0C.
And as for “The upper Arctic shows no signs of warming”
https://link.springer.com/article/10.2151/jmsj.2025-027#Fig2
“Evolution of annual mean surface air temperatures and their differences relative to satellite-derived observation over the central Arctic sea ice a Surface air temperature difference for ERA5 reanalysis [T2m(ERA5)−T2m(SAT)].
https://zacklabe.com/arctic-temperatures/
Everything labeled temperature on this page IS NOT A TEMPERATURE!!!!!
Every “temperature” on this page is an anomaly! You have no idea what the actual temperatures are!
Can going from -13C to -11C give an anomaly of +2? How much ice will actually melt?
It is not an anomaly. It is a “departure from the mean.”
Abuse of anomaly is ongoing.
Yeah I was taught a departure from the mean was a probability like a standard deviation has 68% of the values in that interval. An anomaly has always been out of range, i.e., anomalous.
They use average rather than medium so they can declare to people what to expect. Any departure from the mean is an anomaly, which means abnormal which means scary and you get the point.
“Every “temperature” on this page is an anomaly! You have no idea what the actual temperatures are!”
Not explicitly …. and knowing the actual temperature is not going to reveal the information required … that of the ongoing trend of temperature any better than does the anomaly !
If it is vital you know the actual temp then calculate them from the baseline (1981-2010 for the Artic and 1961-1980 for the Arctic +Global).
“Can going from -13C to -11C give an anomaly of +2? How much ice will actually melt?
Err, yes, as it has risen by +2C !!
We don’t know how much ice would melt as it is an annual average. Frigid in winter -so obviously a build-up and a melt in summer due warming of Arctic landmass (60 deg N includes a fair bit of that ), and direct melt via sunshine.
You are looking for CLIMATE trends. Trending anomalies will *NOT* tell you anything about how the climate is changing.
Is a trend from -20F to -15F a change in climate? Does the anomaly of +5F tell you anything at all about the climate change?
Is a trend from +60F to +62F a change in climate? Does the anomaly of +2F tell you anything at all about the climate change?
Climate change is *NOT* temperature only. Climate change is far more influenced by precipitation changes than by temperature changes. The Central Plains of the US and the Central Africa region have the *same* climate – savannahs with grazing animals predominating – but vastly different average temperatures and temperature variance.
The temperatures won’t tell you a darn thing about climate CHANGE since they are both mainly influenced by precipitation!
“You cannot expect air flowing over that surface to get much beyond 0C.”
And then you link an article that says the exact opposite!
ROFL!!
Reference please
You do know that anomalies are differentials from the mean baseline – and if rising are +ve?
ROLF
I was referring particularly to warming during the melt season, which is when most sea ice loss occurs -: generally March to mid August. Clearly, there has been warming during the winter months but not to the point where large areas of sea ice are lost – especially not 80 degrees north. But during the melt season, this region (according to DMI) hasn’t warmed significantly, and during 2026, as mentioned earlier, has been close record breaking cold.
“But during the melt season, this region (according to DMI) hasn’t warmed significantly”
Correct and it wont while the central Arctic is predominantly sea-ice.
I was referring particularly to warming during the melt season”
I know you were – and my answer remains thus ….
The upper Arctic remains close to 0C in summer due the fact that it is either ice or water at a temperature of at or below 0C.
You cannot expect air flowing over that surface to get much beyond 0C.
“during 2026, as mentioned earlier, has been close record breaking cold.”
Yes it was – by ~ 1C.
“Anomaly of the +80N mean temperature index, compared with climate (annual mean minus the corresponding climate value). All year anomaly is illustrated with the black line, summer anomaly (June, July, August) is illustrated with red and winter anomaly
(December, January, February) in blue. Reference climate is ECMWF-ERA40 1958-2002.”
Yet for the Arctic Above 60 deg N …..
I suspect the reason for the colder summer above 80 deg N was that it was very wet…..
https://alaskaclimate.substack.com/p/arctic-summer-2026-climate-review
“In the far north, the area poleward of 80°N were exceptionally wet (and snowy) this summer, with by far the highest precipitation (and snowfall) since 1950.
They really went to great length to cram the ‘man-made’ into the narrative. If they left it out it might become a decent paper, but then, where do you get it published?
Do you think it could pass peer review with such an egregious spelling error in the graphic title?
Might want to ask Nick. 😉