By Kenneth Richard on 11. August 2025
In 2007 Al Gore won a Nobel Peace prize for predicting summer (September) Arctic sea ice would “vanish” in the next 5 to 7 years, or by 2014.
Since 2007 Arctic sea ice extent (SIE) losses have ceased. Instead, the SIE trend has been stable for nearly two decades (Stern, 2025).
“Before 2007, September SIE was declining approximately linearly. In September 2007, SIE had its largest year‐to‐year drop in the entire 46‐year satellite record (1979–2024). Since 2007, September SIE has fluctuated but exhibits no long‐term trend.”
Image Source: Stern, 2025
Only two years since 2007 when Arctic ice has bottomed out at the Autumn Equinox below four million square kilometres. This year looks a bit dicey! Keep your fingers crossed or the alarmists will be lookitoldyouso.
Arctic sea ice minimum extent depends upon whether there are late summer cyclones or not. In 2007, 2012, 2016 (two!) and 2020 there were.
One can go to that chart and cherry pick any segment and use that to “prove” any claim.
I find the analysis presented is quite rational and reasonable.
The only question unanswered is why the linear decline prior to 2007.
What are the primary and secondary factors contributing to that phenominon.
I doubt the self-proclaimed “Climate Scientist” will even bother to look.
It’s discussed with several references right there in the paper. Most relevant quote is this:
“In any case, the physical reason for the downward trend in Arctic SIE has been confidently attributed to global warming caused by anthropogenic greenhouse gas emissions (Fox‐Kemper et al., 2021). Notz and Stroeve (2016) found that Arctic sea‐ice loss is linearly related to anthro-pogenic CO2 emissions”
Correlation is not causation.
Correlation is cause for further investigation.
A causes B
B causes A
X causes A & B
A & B are independent
It’s quite a surprise to hear anyone claiming that anthropogenic CO2 emissions have had no trend over the last 20 years!
That would seem to be debunked.
Which explains why the current extent is higher than it has been for nearly all the last 10,000 years.. right 😉
You did know current extent is in the top 5-10% of the Holocene, didn’t you ?
Did you do know that 1979 was an extreme high close to that of the LIA ?
There’s still one heck of a lot of sea ice up there. !
CO2 has climbed at an ever increasing rate (great for the planet)…
.. so how do you explain this….
LOL, there were periods of time of far less to NO summer sea ice in the arctic LINK while the CO2 ppm levels were around the 260-280 ppm level for thousands of years while the SUMMER ice coverage varied over time from ZERO to a filled basin.
Your claim is thus invalidated.
The assertion should have stopped there. Continuing to attribute it to anthropogenic greenhouse gas emissions is a bridge too far.
Confidence and consensus? Who needs science anyway.
Well, in fairness, that’s only true if one doesn’t require a minimum number of data points, say 15 or more, to determine a trend over any given interval.
Note that in the above article’s referenced GRL paper Figure 1b the “stable” interval of 2007–2024 was established using 18 data points, as indicated.
A statistically valid population (data set) includes a minimum of 100 data.
That aside, too many times I have seen alarmist reports (media or other) taking a snippet and making wild claims, which is more of my point.
Got any mathematical evidence for that absurd statement?
In comparison, here is what Google’s “AI Overview” states in regard to the question: “How many data points are required to determine a statistically valid trend line?”:
“To establish a statistically valid trend line, you generally need a minimum of three data points, but more points are often recommended for increased reliability and accuracy. While two points can define a line, they don’t confirm a trend, and three points allow for the possibility of identifying a curve or a change in direction.
“Here’s a more detailed breakdown:
• Two Points:
Two data points are the absolute minimum to draw a line, but they don’t indicate a statistically significant trend. They simply show a connection between two points in time.
• Three Points:
With three data points, you can start to see a direction (increasing, decreasing, or flat). You can also begin to identify if the data follows a curved pattern.
• Four or More Points:
As you add more data points, you increase the reliability and statistical significance of your trend line. More points allow for better identification of outliers, trends, and potential shifts in the data.
• Factors Influencing Recommended Points:
The specific number of data points needed also depends on:
• The nature of the data: Some data might require more points to account for natural variability.
• The type of trend being analyzed: Linear trends might require fewer points than complex, curved trends.
• The desired level of accuracy: More points lead to more accurate trend analysis.”
I think I’ll go with Google’s response rather than your asserted need of 100 data points minimum . . . which for any measured parameters averaged annually over the last 99 years or less would preclude establishing any sort of trend (e.g., forget about establishing trends) based on annually averaged satellite data points.
LOL!
The AI mentioned nothing about evaluating a time series. Are the mean and standard deviation constant in the series, i.e., stationary?
Nor did Sparta Nova 4 in his/her previous post.
Not that statistical analysis of any set of x-y data points cares squat about what particular units of measurement are used for the x- and y-axes!
His.
My error was not applying my response to a time series, which was an incorrect point of view. The 100 data in a population set has many applications, but obviously not time series.
The point I was making was the second part. Scan and scroll misled a few too many.
“That aside, too many times I have seen alarmist reports (media or other) taking a snippet and making wild claims, which is more of my point.”
What about cyclic data – I think one needs about 8 – 10 points per cycle to even see that behavior.
These are time series. (year,value). Unless you have a functional relationship that has time as the independent variable, the number of data points is really meaningless.
You only need two points to draw a trend. Guess what the statistics show for that? Do some time series analysis to see what you find. Have you done a unit root test?
I’ll just let that statement stand on its own, for all WUWT reads to contemplate.
I am certain that even the IPCC would disagree with that, although many AGW/CAGW alarmists will be in full agreement, permitting “cherry picking” of those two data points. ROTFL!
“You only need two points to draw a trend.” Mathematically correct. Totally pointless.
Errr . . . weren’t you just referring to using two points?
Perhaps it was a decline from a high? Satellite measuring started only in 1979 and prior accounts from ships logs.
Precisely. Yes, it was an extreme high around the late 1970s..
Also the peak of the AMO.
Also the coldest period in the Arctic after the 1940’s high, which similar in temperature to the early 2000’s in “unadjusted” surface data)
Looks like a sine wave is the best fit….
My thinking was along that lines.
It is seasonal which needs to be accounted for. An SARIMA analysis needs to be done
Probably more factors influence it, too.
Arctic sea ice seems to follow the AMO cycle closely. (sea ice inverted)
Hey man, you gotta put years on there to mean anything. Like this….notice they quit trying to spiral us to death a dozen years ago…
…it’s a sarc
I feel the real question should be why there was such a dramatic decline in 2007. And the second question being why it didn’t recover back to the pre-2007 trend.
Low years are all due to late summer cyclones.
The downtrend ended in 2007-12 because it’s a natural cycle.
The natural Arctic sea ice cycle is what drives the 60-70 year AMO index. We are due for another phase transition (warm to cold) within the next couple of years.
Perhaps. It is also possible that the AMO cycle influences the Arctic sea ice cycle.
It is also possible the two are mutually interacting.
It is also possible both are caused by some other source.
Not according to Stern.
Not according to Stern.
Here’s a shock: data analysis and data attribution are two distinct things. They’re not interchangeable, and when reading a paper, it’s entirely possible for the statistical analysis to be robust while the attribution component is not. You don’t need to agree with every aspect of a paper to find it valuable.
Stern is wrong.
After an extreme high in 1979, sea ice levels dropped slightly back towards more normal levels.
Arctic sea life is happy !
Stern looked at junk models from the climate alarmist farce..
.. NOT REALITY !!
Then maybe WUWT should stop posting articles from guest authors who don’t realize they are citing sources contrary to one of the thesis WUWT promotes.
Why should it?
The real question should be why nearly all of the decline during the POR occurred from 1996-2012, a sixteen year period. Perhaps it was a lot of dirty, multi-year ice finally melting off.
The joy of cherry-picking trends. This articles claims there has been no decline since 2007, you claim the decline continued until 2012.
Usually I would say that a linear decline with a lot of random, probably autocorrelated, variation was the simplest explanation. But with sea ice expanse, I suspect a linear response would be unlikely. It could well decline in fits and starts given the nature of melting ice, and the geography of the region.
I picked 2012 because it happened to be the lowest year. If I choose 2007, then the only meaningful period of decline is a mere 11 years. Hardly a trend, more like a short “drop”.
Arctic sea ice since 2007
Far more likely to follow the AMO, which means it will probably start to increase at some stage in the next few years.
Absolutely nothing to do with CO2, that is for sure.
As shown above, Arctic sea ice tends to follow the AMO.
Will be fun watching the sea ice worriers as the AMO cycle starts to trend downwards again. 😉
Did you know that around 1979 was an extreme high anomaly , similar to the LIA.
What we saw from 1979-2007 was a slight RECOVERY towards more normal Holocene levels.
It allowed a lot of sea creatures that had been driven out by too much sea ice, to come back to the Arctic waters.
Why do you describe the 2007 decline as ‘dramatic’? There were increases of similar magnitude in 1995 and 2012. So hardly an unusual occurrence.
And why do the Arctic sea ice worriers think that having the Arctic chock-full of sea ice all year round is in any way a “good” thing ?
Makes travel by sea impossible.
Drives sea life out of the Arctic (that used to be prevalent during the MWP and is only just starting to return on the peripherals)
Too much sea ice, is actually a very BAD thing for all animals and creatures trying to exist up there.
It’s the entire premise of this article that there was a regime shift in 2007.
“ that there was a regime shift in 2007.”
Which is absolutely correct.
Yet another nail in the “CO2 done it” coffin. !!
Here is OSI data from 2005. Anyone can see its been close to level since 2007.
Ocean cycles again…
Based on that SST graph, the sea ice has hung in there surprisingly well for the last 2.5 years.
Maybe an ocean is not a perfect correlation. Also, sustained warming might be required for longer.
There are always possibilities.
The problem is proof when there is no means to test the hypothesis.
Not testable?–That may be important that the gateway to the Arctic is not testable.
You seem to be conflating to different points.
No
Just lovely, these Reality Checks. Looks like the 46 year satellite data is a good short-term data source, whereas sea level is a good long-term data source. Al (SexPoodle) Gore….not so much.
Looks like you missed the most pertinent quote from the paper:
“Whatever the reason for the near‐zero trend during 2007–2024, Arctic SIE is predicted to continue declining due to increasing global average air temperature caused by anthropogenic greenhouse gas emissions. Based on global climate models, there is “high confidence that the Arctic Ocean will likely become practically sea ice free in the September mean for the first time … before the year 2050” in all emissions scenarios”
Or look at a better measure of the physical ‘health’ of the ice than SIE which is volume (SIE is and always will be a somewhat artificial measure):
https://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/
“is predicted to continue”
They have predicted a great many things and none of them have ever come close. This could well be why people laugh? I certainly laugh, it gets streamed constantly on the BBC
“a better measure of the physical ‘health’”
You won’t get one under net stupid zero, remember the motorcyclist who was killed in an accident and died of Covid?
OK, let’s look at the PIOMAS reconstruction for “Arctic sea-ice volume”, currently available up to 31/7/2025, plotting the monthly averages.
There is some “natural variability / inter-annual noise”, but it looks to me as though the 12-month (centered) rolling average “levelled off” around the 14,000 cubic kilometres line around 2010/2011.
That’s 15 years of relative stability now …
Through the end of 2024, I plotted a Lowess smooth of each month’s data separately. The rate of loss of estimated ice volume obviously decelerated for all months leading up to 2010 or so. Will it continue leveled out? No one knows.
https://drive.google.com/file/d/1uYOcw9aCBzsAzy_LYth9qKP-2wKVrHKt/view?usp=sharing
PIOMAS since 2011
Currently the Arctic sea ice volume according to PIOMAS is about 6,500 km^3 about 1,000 km^3 less than the 2010 decadal average for the date and close to 12,000 km^3 less than the 1980 decadal average. So over the last 45 years it’s dropped by over 60%. I’d expect the minimum this year to be below 4,000km^3.
First, there is no strong scientific evidence that anthropogenic greenhouse gas emissions cause increasing global air temperatures.
Second, there is strong scientific evidence (ref. Happer, et.al.) that the effect that CO2 had as a greenhouse gas at atmospheric concentrations below about 300 ppm has reached its asymptotic limit (the effect is “saturated”) such that any additional CO2 in the atmosphere—whether from natural causes or from mankind burning fossil fuels and making concrete—has an insignificant additional greenhouse impact. We are currently at about 425 ppm CO2.
Third, anthropogenic emissions of methane are an insignificant contributor to the net greenhouse effect taking place in Earth’s atmosphere because its predominant LWIR-absorption band between 7 and 8 microns is overwhelmed by that of water vapor in this same spectral range. Nitrous oxide as a greenhouse gas to worry about? . . . don’t make me laugh!
Fourth, you say “based on climate models” . . . there, you just made me laugh!
Finally, you say “pertinent”, I say “absurd”.
You missed the point that the energy stored in the ocean is much greater than the energy in the atmosphere.
The point being, it is much more likely that Arctic Sea ice melt and accumulation is related to the ocean rather than the atmosphere.
No, I didn’t “miss the point” . . . it was never there.
Please re-read the above discussion thread and the above article and point out where energy stored in the ocean was compared to energy stored in the atmosphere.
Furthermore, there was no discussion as to the source of energy that accounts for Arctic sea ice (SIE) changes other than asserted GHE atmospheric warming.
“Please re-read the above discussion thread and the above article and point out where energy stored in the ocean was compared to energy stored in the atmosphere.”
It’s not mentioned because it’s a basic sidebar of global warming. 90% of heating goes into the oceans. Warmer oceans melts sea-ice. People don’t have to prove that 1+1=2 in every maths paper.
“First, there is no strong scientific evidence that anthropogenic greenhouse gas emissions cause increasing global air temperatures.”
Jesus.
“Second, there is strong scientific evidence (ref. Happer, et.al.) that the effect that CO2 had as a greenhouse gas at atmospheric concentrations below about 300 ppm has reached its asymptotic limit (the effect is “saturated”)”
That almost certainly implies they don’t understand how global heating due to increased CO2 levels works. They’re modelling how heating occurs is taught to 11th grade students or how it’s explained in climate denier circles. Not how it actually happens. Many clever people get it wrong: See the PhD section in https://www.youtube.com/watch?v=oqu5DjzOBF8 The ditch can’t get any deeper, but it can get wider => absorption is not saturated.
Above you say AGHG has no effect and then you quote Happer et al as proving that the effect gets saturated at a certain point. Which is true? – They both can’t be true.
“Fourth, you say “based on climate models” . . . there, you just made me laugh!
Finally, you say “pertinent”, I say “absurd”.”
It’s not me saying it – it’s in the paper by Stern et al.
” there is no strong scientific evidence that anthropogenic greenhouse gas emissions cause increasing global air temperatures.””
A nearly true statement. What is your problem with it?
(There is actually no evidence at all)
Perhaps you have evidence no-one has ever produced.
The fact that they teach an erroneous model of atmospheric warming to 11th grade students is part of the problem… You seem to have not progressed since then.
That petty and childish word “denier” again…
… tell us what we “deny”. and produce real scientific evidence to back it up.
First, I don’t have a “problem” with that statement . . . I MADE IT!
And just to clarify for you, pre-industrial atmospheric CO2 levels have been scientifically estimated to be about 280 ppm (https://www.noaa.gov/news-release/carbon-dioxide-now-more-than-50-higher-than-pre-industrial-levels ).
Happer and other eminent atmospheric physicists have estimated that atmospheric CO2 becomes asymptotically “saturated” in its greenhouse effect at levels of about 300 ppm. Hence, admitting that mankind’s emissions of CO2 MAY HAVE contributed to a slight increase in CO2 greenhouse effect from 280 to 300+ ppm, I caveated my statement with the phrase “no strong scientific evidence”.
Your post is very confusing as to what you imply I am “denying”.
Now, you were saying something about being “childish” . . .
Will is not an “eminent atmospheric physicist” his specialty is atomic physics, optics and spectroscopy!
Google’s “AI Overview” rebuttal (with my bold emphasis added):
“William Happer has published approximately 250 papers and books in total. It’s not explicitly stated how many of these are specifically on atmospheric radiative transfer, but he is known for his work in atomic and molecular physics, optical physics, and radiation propagation in the atmosphere. He has also been described as a “Climate Physicist”. Here’s a more detailed breakdown:
Total Publications:
Happer’s publications exceed 300, including articles, commentaries, interviews, lectures, testimonies, and podcasts.
Climate Physics:
He has published 18 “Premier Climate Physics Articles” and 32 other articles, commentaries, etc., related to climate.
Specific Focus:
Happer’s expertise includes atomic, molecular, and optical physics, as well as radiation propagation in the atmosphere, according to the CO2 Coalition.
Climate Change Views:
Happer is known for his view that the effect of increased CO2 on climate is small due to the saturation of CO2 absorption bands.“
Obviously, I stand by my statement that William Happer is an eminent atmospheric physicist.
But maybe you think that expounding on climate and radiation propagation is far removed from the physics required to understand Earth’s atmosphere and its changes? /sarc
That’s the problem of relying on AI! Will’s expertise is in the field of optically polarized atoms, a major contribution was the development of a technique for the magnetic resonance imaging of lungs (he formed a company to do that which became part of General Electric).
Even if I assume that claim is true, you conveniently overlook how much of that “heating” goes back into Earth’s atmosphere via water evaporation off Earth’s ocean surfaces within a period of, oh, 24 hours or so.
Perhaps you have forgotten that Earth has a hydrologic cycle that is very effective in rapidly distributed energy from water surfaces to the atmosphere (see https://www.noaa.gov/jetstream/atmosphere/hydro )
Bottom line: heat that goes into the oceans doesn’t stay there for long. The hydrologic cycle is the major explanation for the rather amazing stability of Earth’s surface temperatures over thousands of years.
It’s not overlooked. That 90% figure includes latent transfer to the atmosphere plus a bunch of other things.
I don’t understand that scientific term “a bunch of other things”.
“Finally, you say ‘pertinent’, I say ‘absurd’.”
Posted by twofeathersuk above at 7:57 am on August 13, 2025:
“Looks like you missed the most pertinent quote from the paper:”
No further discussion necessary.
You are correct. I apologize. I misread your post.
They have to include this to get published. If there is truly a hiatus over the last 17 years then maybe they should rethink their conclusion. Or take another look at the assumptions they are using to draw that conclusion.
“Based on global climate models,”
Copy that.
“Based on global climate models”. Using which scenario? RCP-8.5?
I look at this NSIDC web page every day. Back in June they expected to stop processing because of the pending loss of data from the DoD SSMIS. Oh no! It’s that anti-science Trump administration!!
Then the DoD extended the availability of that data through the end of July. Now they seem to have implemented an update using an alternate satellite source. No biggie. Never mind all that hand-wringing.
https://nsidc.org/sea-ice-today/sea-ice-tools/charctic-interactive-sea-ice-graph
“The daily images for Sea Ice Today now uses input data from the JAXA GCOM-W1 AMSR2 passive microwave instrument. AMSR2 replaces the previous data source, the Defense Meteorological Satellite Program (DMSP) SSMIS passive microwave instrument. For further details, see the NSIDC news announcement: New version release: NOAA/NSIDC Sea Ice Index, Version 4. ”
“Oh no! It’s that anti-science Trump administration!!”
Well, they chose to choke off a US data source previously open to the public. And a work around was found, for graphs, using Japanese data. But if you go to the data page, you find:
“Notice: Due to funding limitations, this data set was recently changed to a “Basic” Level of Service. Learn more about what this means for users and how you can share your story here: Level of Service Update for Data Products.”
And if you follow the link, you find:
” Basic—meaning they will remain accessible but may not be actively maintained, updated, or fully supported.”
Thanks for stopping by, Nick! Be well.
Be afraid, David.
Nick (Sherlock) Stokes is on this case now.
(soon to be joined by Inspector Clouseau?)
Up to date at 13th August.
Following 2024 quite closely.
I doubt it will drop below 4 Wadhams this year unless there is a major storm that forces ice out through Fram Strait.
To give an equivalence, 4 Wadhams is about half the area of the contiguous USA.
That is one heck of a lot of sea ice. !!
Well sea ice extent is the area of the sea which is covered by at least 15% of ice a more reasonable measure is the actual area which will be below 3 Wadhams!
From that second link “New version release…”:
“This change was driven by the upcoming loss of access to SSMIS data and the degradation observed in current SSMIS data, as these instruments are well past their designed lifespan.”
That’s it. That’s the whole story.
“upcoming loss of access to SSMIS data”
Yes.
“… these instruments are well past their designed lifespan“
You just wait until 2035, or 2050 or 2070 or end of the century, or….
Below
According to the author we won’t need to wait long. He expects the summer minimum to continue declining as a result of anthropogenic greenhouse gas emissions.
You misread.
and
Extrapolation from a trend ended 13 years ago isn’t science. It’s politics.
if decline in Arctic sea ice minima from 1979 to 2012 were due to CO2, why did Antarctic sea ice grow so dramatically from 1979 to 2014?
Predictions based on models and assumptions. YAWN !!
F=ma is model of reality that relates force, mass, and acceleration. If we assume a 1 N force and 1 kg mass is it really not worth more than a yawn to expect a 1 m.s-2 acceleration? When are models and assumptions worth more than a yawn?
Oh dear, you aren’t seriously trying to equate a basic physics model with fake anti-science climate models
That’s an hilariously stupid thing to do.
If there were dozens of alternative definitions of force that gave a wide spread of possible values, you might have a point.
That model is not the only definition of force. It’s why I used that model as an example. In fact, we know for a fact that F=ma does not correctly model reality. Yet it is used nearly ubiquitously. Why do you think that is?
Oh, history is replete with excellent example of that . . . even much, much greater worth than a yawn.
I suggest a good starting place for you would be for you to understand the history and processes than mankind went through to develop and control atomic fission, based extensively on mathematical models and various assumptions concerning nuclear reactions and what was needed to initiate/enable such.
Unfortunately many Japanese citizens ended up considering that development significantly “more than a yawn” . . . as, eventually, did the rest of humanity.
You said “he expects” which is a misread.
He literally uses the word “expect”.
There is one long term trend in all this, the wrongness of Gore, Wadhams, Maslowski
and all the other ice free Arctic sages. And that trend just goes on.
It doesn’t matter what the “sages” say.
Rather – what the science says ….
“Figure 1. Percent change in March (red) and September (blue) Arctic sea extent w.r.t. 1979-1988 in the CMIP3 ensemble and NSIDC observations. Spread is the 95% CI (with a 10 year smooth to reduce visual clutter). Solid lines are the ensemble mean. Historical forcings are used to 2000, and the SRES A1B scenario subsequently.
CHIP3 is not science.
It is a model.
Just like the Ideal Gas Law is a model!
Not the word “Law” in that title.
That means it has passed the null hypothesis test and is proven to be valid across well defined boundaries.
V = I x R is certainly a model.
A proven, reliable, null hypothesis tested model.
Were it not for the rigor applied proving that model, we would not be posting today.
The Ideal Gas Law is a model which assumes that molecules are infinitely small and that there are no molecular interactions. As a result it is most accurate for monatomic gases at low pressures and high temperatures. The Van der Waals equation is a more accurate description of real gas behaviour.
Now that we have the computer horse power, we use equations of state for Z factors for petroleum gases. They’re tucked into all modern nodal analysis and reservoir simulation softwares. I think you can get real weedy and fine tune the model parameters, but since it matters hardly at all most petroleum engineers just click away.
F=ma is a model and is considered to be a “law” as well. The irony is that we’ve falsified it yet it is still used nearly ubiquitously by everyone. Why do you think that is?
Anyway, if you don’t think model’s are science then you aren’t going to be satisfied with science in general since one of the foundational tenants of science is creating models that explain and predict reality.
We use it “nearly ubiquitously” since it is more than adequate for most things that we do, and in the places where we live. It is false because it doesn’t reflect relativity, having to do with “a” leading to “v” near “c”. For the rest of the time, F=ma is more than adequate.
You really love those JUNK climate models don’t you.
You do realise that they show whatever the modellers want them to show, don’t you. !!
All you have managed to show is that the modellers were totally clueless… and remain so.
It shows that the model predictions underestimated the decline in sea ice extent! The current values are already below the predictions for 2050.
Thanks for confirming that ‘science’ really doesn’t understand what’s going on.
Yes, but up in the skies….there is more turbulence according to airlines….why? You have one guess….a hint is warming oceans are involved..
One minor correction, AlGore;TheGorecle was not wrong, he lied. Repeatedly.
. . . besides which, he took the money and ran.
But I understand that Gore’s desire for attention (or is it really money?) has caused him to return to the “rubber chicken circuit” of paid lectures and paid keynote speeches. That’s a really inconvenient truth.
2024 minus 2007. That’s more than halfway through the IPCCs 30-year climate definition. If the “flat continues” for the next 13 years then we can say more. If not, then we should all start (restart?) running around in circles waving our arms over our heads.
No we shouldn’t. A warmer climate, compared with the Little Ice Age, is a better climate. No hand wringing or arm waving is necessary.
This is really simple “science”. I was doing the exact same thing on my computer last year, and I am a retired nobody with an internet connection. However, it is nice seeing mainstream science acknowledge this situation, which is inconsistent with the mainstream narrative. Next, time for an article on that persistently large ozone layer.
If the past is a guide, the climate alarmists will just move on. They already have. Now they hype droughts, floods, and forest fires as climate change.
They know what they are doing. A large mass of voters is too insensate to notice the scam.
50 years or more and counting and the uproar from the professional activist/alarmist crowd is reaching hearing damaging decibel levels.
But you were focused on sea ice. My bad. 🙂
Just to emphasize a point others have made, this is based on the satellite record, going back only to 1979. That is a pathetically short time span to argue about.
And has the convenient cherry pick of beginning at a point where sea ice was abnormally high, thus creating the illusion that today it is abnormally low, which it is not.
The trend from 2007 to 2024 of only the Septembers (18 values) is -0.1e6 km2.decade-1.
The trend from 1979 to 2024 of only the Septembers (46 values) is -0.8e6 km2.decade-1.
The trend from 2007 to 2024 of all months (216 values) is -0.5e6 km2.decade-1.
The trend from 1979 to 2024 of all months (552 values) is -0.5e6 km2.decade-1.
So while the summer minimum extent has been relatively stable since 2007 the overall extent continues to decline at about the same rate as it has been since 1979.
Of course it does…
I should point out that Stern believes that Arctic sea ice extent will continue to decline as a result of anthropogenic greenhouse gas emissions either as a steady decline or as a stepwise change like what happened around 2007. Either way there is high confidence that the Artic region will be practically sea-ice free at least once before 2050 he says.
I should point out that Stern was discussing someone else’s research that presented that possibility.
You should also be pointing out that Stern is discussing someone else’s research throughout the whole publication. That’s par for the course with any peer reviewed publication that cites its sources.
You said “Stern believes.”
I know.
What is the straight line slope of a sine wave from 90 to 270?
For a linear regression trend it is m = -0.0135 and b = 2.4304 where y = mx + b.
For a line directly connecting the end points it is m = -0.0111 and b = 2 where y = mx + b.
What does that have to do with the price of beans in China?
I have no idea.
The correct answer is, it is irrelevant to a sine wave.
So why did you ask?
It was a learning opportunity for those who don’t consider cyclic behavior.
What cyclic behavior and what is causing that behavior?
A RECOVERY from an extreme high in 1979…. levelled out in 2007..
Here are min, max and average since 2007.
The Climate Caterwaulers were riding high back then in 2007, what with The Inconvenient Truth, the Arctic Death Spiral, the threat of Polar Bear extinction, the Methane Bomb, and so much more. All of it total nonsense, of course, but we were told in no uncertain terms that “the debate is over”. And now look at them, clutching desperately to their “extreme weather is climate change” idiocy, because that’s really all they have now. Pathetic.
At 7am this morning, the temperature in my (rather cramped) hotel room was 20deg C. An hour later it was 21deg C. I checked out shortly afterwards and didn’t have time to measure it again but it certainly felt warmer. I therefore conclude there is a linear temperature increase of 1deg C per hour. By 7am tomorrow, the temperature in the room will therefore be 44deg C and at 7am the day after 68deg C.
Please may I have a Nobel Prize? I really, really want one and I’ve contributed at least as much to science as Al Gore. Please?
It’s too short a period to be sure of anything. To my mind, Figure 1(b) is unconvincing. When I do a multiple linear segment fit to data, I make it contiguous. The gap in Figure 1(b) renders it unsuitable as a visual fit, unless there’s a reason for the gap. There’s nothing in Figure 1(a) that makes it obvious that the linear fit is incorrect, but by the same token there’s nothing to suggest that a different line could not be better. Maybe data starting in 1684 could resolve the issue.
Agreed on the short time period.
It is also possible that the data is 3 trends. Up to 2007, 2007 to 2012, and 2012 to present. It could also be defined as the 2007 to 2012 as part of the earlier droop and 2012 to present is part of the recovery.
The time period is too short.
The coverage of sea ice on the Arctic Ocean was the subject of then Senator Kerry’s (aka ‘Lurch’) pontification on the Senate floor in 2009. He boldly predicted, based on his tame scientist’s bolder exponential extrapolation, that summer Arctic Ocean ice would disappear by 2014. That did not happen. A not bolder, but older, scientist’s less aggressive linear extrapolation pushed the date to 2030. That could work out yet since 2030 is ahead and extrapolation beyond the last data point is just a guess.
Since multiyear ice is thicker, even with no area change, the ice can decline in volume as multiyear ice declines! There is more than one way to show an ice decline.
To the point, fluctuations in the ice coverage require very small changes in the insolation to melt said ice. My elementary climate students answer the question – how many days of solar insolation are required to melt 10 million square kilometers of one meter thick sea ice”. The answer is so short a time that a minor trend in cloudiness in a multidecadal Arctic oscillation can easily cause the observed trend, and its cessation.
Even more to the point, the minimal area and volume change over the past 15 years or so means very little, just as the change since 1979 means very little. Our friend ‘Lurch’ made the claim that a large difference in the normal reflectance of ice (~90%, if it were snow-like) and open water (~4%, for water) meant the loss of ice would accelerate the melting and warm the Arctic Ocean. His tame scientist never read about Fresnel reflection’s dependence on the incident angle. Arctic sea ice and open water, in fact, have a similar albedo (the attached plot shows this). There are two reasons.
1. The f/100 solar insolation incidence angle in the Arctic Ocean averages ~80 degrees, and
2. Sea ice is not snow, forms from impure sea water with a much lower normal incidence albedo than snow. The two graphs show this and along with the insolation ‘beam’ of light.
A-plus.
The coverage of sea ice on the Arctic Ocean was the subject of then Senator Kerry’s (aka ‘Lurch’) pontification on the Senate floor in 2009. He boldly predicted, based on his tame scientist’s bolder exponential extrapolation, that summer Arctic Ocean ice would disappear by 2014. That did not happen. A not bolder, but older, scientist’s less aggressive linear extrapolation pushed the date to 2030. That could work out yet since 2030 is ahead and extrapolation beyond the last data point is just a guess.
Since multiyear ice is thicker, even with no area change, the ice can decline in volume as multiyear ice declines! There is more than one way to show an ice decline.
To the point, fluctuations in the ice coverage require very small changes in the insolation to melt said ice. My elementary climate class answers the question – how many days of solar insolation are required to melt 10 million square kilometers of one meter thick sea ice”. The answer is so short a time that a minor trend in cloudiness in a multidecadal Arctic oscillation can easily cause the observed trend, and its cessation.
Even more to the point, the minimal area and volume change over the past 15 years or so means very little, just as the change since 1979 means very little. Our friend ‘Lurch’ made the claim that a large difference in the normal reflectance of ice (~90%, if it were snow-like) and open water (~4%, for water) meant the loss of ice would accelerate the melting and warm the Arctic Ocean. His tame scientist never read about Fresnel reflection’s dependence on the incident angle. Arctic sea ice and open water, in fact, have a similar albedo (the attached plot shows this). There are two reasons.
1. The f/100 solar insolation incidence angle in the Arctic Ocean averages ~80 degrees, and
2. Sea ice is not snow, forms from impure sea water with a much lower normal incidence albedo than snow. The two graphs show this and along with the insolation ‘beam’ of light.
none of the uneducated will understand this and how they were badly duped.