Almost two decades ago, some scientists predicted that Arctic summer sea ice would ‘soon’ disappear. These predictions were mentioned by Al Gore and got a lot of press. However, they did not gain wide acceptance in the scientific community, and were swiftly disproven. Unsurprisingly, this still comes up a lot. Time for a deeper dive into what happened and why…
It is unsurprising that climate contrarians bring up past ‘failed predictions’ to bolster their case that nothing need be done about climate change. [It is equally unsurprising that they don’t bother to mention the predictions that were skillful, but let’s not dwell on that!]. For a long time, their favorite supposed ‘failed prediction’ was that there was a consensus about the imminence of a new ice age in the 1970s (a topic we have covered many times), but more recently it has turned to the supposed prediction of Al Gore that “Arctic summer sea ice would disappear” in a short number of years. This has everything – the ‘But Al Gore!’ knee-jerk, a conflation of Al Gore with the scientific community, it’s sounds suitably apocalyptic and, of course, Arctic summer sea ice has not disappeared (it’s only down 40% or so):
What did Al Gore actually say?
If we go back to Dec 2007, in the immediate aftermath of the shocking decrease in sea ice that summer, Gore gave his acceptance speech for the Nobel Peace Prize he’d received jointly with the IPCC. In it he said:
Last September 21, as the Northern Hemisphere tilted away from the sun, scientists reported with unprecedented distress that the North Polar ice cap is “falling off a cliff.” One study estimated that it could be completely gone during summer in less than 22 years. Another new study, to be presented by U.S. Navy researchers later this week, warns it could happen in as little as 7 years.
What was he reporting on?
This was truthful reporting. The first study (I think) refers to a commentary piece in EOS (or perhaps a preprint of it), which noted the poor performance of climate models in tracking the Arctic sea ice loss, and made an expert guestimate that summer sea ice would be gone by around 2030. The second (upcoming) one, refers to a fall AGU 2007 presentation that would be given by Wieslaw Maslowski, who at the time ran one of the highest resolution ice models available. However, his prediction was not directly based on his ice model, but rather on a linear extrapolation of the ice volume from his model:
One might sensibly ask why a prediction made in 2007 only made it into a review paper in 2012, despite having been highly publicised at the time? We’ll get to that.
Gore continued to reference Maslowski’s prediction at least through to 2009.
Over the next few years, a few other folks got into the sea ice forecasting game using similarly somewhat unorthodox methodologies. Chief among them was Peter Wadhams, an emeritus professor at Cambridge University. Wadhams (and a group that styled themselves the “Arctic Methane Emergency Group” (AMEG)) started showing graphs of extrapolated ice thickness from the University of Washington’s PIOMASS model:
Even without being an expert in sea ice, one might question some of these methods: naive fits to noisy data being extrapolated out of range, the odd fact that the same methods applied to extent or area data gave vastly different times of ice-free conditions, and, most obviously, a lack of any physical modeling for the future state. Sure, the standard climate models (CMIP3 at the time) used in scenarios were behaving too conservatively, but to ignore them completely…?
I don’t recall whether I was at Maslowski’s talk in AGU 2007, but I recall seeing him present similar results at least a couple of times. And even if he wasn’t present, his results were discussed widely among relevant scientists at multiple workshops. As far as I recall, opinions were pretty sharply negative.
What is the physics behind your prediction?
In 2014, the Royal Society hosted a workshop on Arctic sea ice reduction. I was invited to give a talk on paleo-climate perspectives on sea ice change, modeling and methane. Notably, Peter Wadhams was there and presented a graph very similar to the one above. If you hunt around carefully in the wayback machine you can find some of the audio recordings from the meeting, and specifically, if you listen to the Q&A period from his talk, you can hear me ask [43:00] whether there was any physical basis for such an extrapolation. The answer was no. [As an aside, this was one of the first climate workshops that really embraced Twitter (as it was then) as a means of broader dissemination, though this wasn’t appreciated by this particular speaker!]. Bizarrely, Wadhams maintained his confidence that 2015 (less than a year away at this point) would be ice free in summer.
To be clear, I claim no specific brilliance in being sceptical of these predictions. Almost everyone in the field was unconvinced by these extrapolations from the initial 2007 AGU meeting presentation onward. The reason why these predictions never made it into a peer-reviewed publication? I imagine that it was the difficulty in finding any reviewers that found these methods credible.
Lessons learned?
Science is very competitive, and scientists guard their independence fiercely. For them to agree on even one thing is major effort. Thus there will always be a range of opinions and methods on any topic and people who will cling strongly to them. The desire and culture of assessments (such as the IPCC) arose specifically in order to distill that broad range across individual scientists into a more coherent and better balanced assessment that a larger majority of experts will agree to.
In retrospect, it is clear that some folks were fooled by randomness, giving too much weight to the wiggles and not to the longer-term trend (which, to be honest, is a ubiquitous problem):
One could look back at this episode and what has been made of it since and declare that scientists should have somehow prevented Maslowski and Wadhams from presenting their ideas or talking to journalists or recovering politicians. But that is absurd: No scientist or group of scientists has that power, nor would they even want it. Alternatively, other scientists could have loudly expressed their scepticism at these results and produced better assessments. But both of these things happened. Some even went further and started betting against the extreme predictions (quite successfully in retrospect). For serious people, interested in serious projections, that might be enough. However, all of this will be (and are) ignored when someone wants to get a laugh line on Fox News.
If people are really interested in what the scientific community thinks, the assessed projections from IPCC and similar are your best bet. It can be useful to look at the range of individual projections or opinions, particular in fast moving situations, but it is very hard to discuss them in a public manner that is immune from later distortion.
References
- W. Maslowski, J. Clement Kinney, M. Higgins, and A. Roberts, "The Future of Arctic Sea Ice", Annual Review of Earth and Planetary Sciences, vol. 40, pp. 625-654, 2012. http://dx.doi.org/10.1146/annurev-earth-042711-105345
What’s the physics?
As I recall, there were lots of people here going on and on about this even recently, and I at least kept pointing out that…
the ice keeps recovering!
The max value declined at a much slower rate than the min, because, duh, insolation in the winter is much much less than in the summer. So having even an “ice free” *just* September would require some new increase from the typical energy input for the melting season.
That’s the physics.
(Maybe that aerosol thingie that’s the new favorite for incoherent “debates” will do the trick?)
Thank you for this assessment of Arctic sea ice projections. Would you also be willing to assess an IPCC 1992 warming projection on your ‘Model-Observation Comparisons‘ page? This projection was not included in your Hausfather et al. paper.
If you are interested, then the information for the projection is below:
Observed warming is near IS92a, and observed forcing is a bit above IS92a:
Also, that 1992 warming projection and implied TCR differs from the IPCC 1990 First Assessment Report and IPCC 1995 Second Assessment Report discussed in figure S1 of Hausfather et al..
Here’s the 1990 report:
And here’s the 1995 report:
It is certainly a mistake to pay too much attention to short term “wiggles”. That said it is equally a mistake to pay too much attention to short term flatter areas.
Interestingly, as Gavin notes, the expert community never did pay excess attention to short term wiggles from Day One. Our resident deniers on the other hand never ever give up paying attention to any of their short term flats.
Thank you Gavin for the enlightenment. Very informative.
Seems to me that the combination of Maslowski and Wadhams’ works, Gore’s well-intentioned flogging, and the separate dreadful distortion called ‘Climategate’ were all quite successfully combined to distract and spike suspicion of many in the U.S. public (amplified by the deep economic contraction of 2008 and the lengthy recovery stretching over several years). Not that any individual action was, by itself, necessarily so dreadful, but the combination was (imo).
And with the general public then not interested in big climate related action, the Obama administration and the Congress focused on other pressing issues. It all was good timing for events like the O&G shale boom. Less so for climate scientists in general and those working to arrest GG emission growth rates.
“Less so for climate scientists in general and those working to arrest GG emission growth rates.”
Arresting growth rates? That’s what caused the economic contraction during the pandemic travel lockdowns. That kept carbon in the ground. But today that makes it difficult to continue the transportation needed to complete the transition to solar, wind and nuclear.
“Less so for climate scientists in general and those working to arrest GG emission growth rates.”
KT: Arresting growth rates? That’s what caused the economic contraction during the pandemic travel lockdowns.
BPL: He said “GG emission growth rates.” Greenhouse gas emissions, not economic activity.
Quote: “Arctic summer sea ice has not disappeared (it’s only down 40% or so)..” ONLY?? Expert comments please.
Well, I’m not a climate expert, but I’m damn good at irony–and I’d say Gavin is, too.
And yet, I sit here distinctly remembering the scientific community celebrating that someone with as much political clout as Al-Gore was talking about it.
Saying ‘Surely we could overlook a few ‘minor’ inaccuracies if him doing a movie helped the cause’. Because the message ‘has’ to get out there!
No, this is what you get when you don’t gate keep. When you don’t treat who and how your message gets pushed in favor of just getting it out there.
You gave the deniers the ammo they shot you with. Then act all shocked when you can’t seem to counter the person who you were SO eager to have help, Is now used rather factually, which you admit here. To show, even if you can, and do prove, those predictions were never accurate in the first place.
Doesn’t matter. Two rules of public discourse, The first person to put up a coherent narrative wins the debate.
And
Showing a factual inaccuracy of your opponent is worth more than proving your own facts.
Re. “Showing a factual inaccuracy of your opponent is worth more than proving your own facts.”
Disagree. The resident denier crew here continually posts factual inaccuracies here (think kia’s eyeball (!) correlations and noncorrelations just for starters), yet I see little to no evidence that pointing out their inaccuracies has slowed them down in the least.
Nor was Gore inaccurate in stating what he stated.
This is like blaming all Democrats and liberal open minded thinkers for Charlie Kirk’s murder. Apparently anything other people do is an excuse to eliminate the entire realm of human knowledge, experience, and tolerance. I reject this premise.
Paul Beckwith and his ilk have gone on and on (afaik, he’s not even a terrible scientist outside his obsession). We will never be able to control the rogue actors among us. The blame game is endless.
Let’s not forget that there was a typo: 2035 is not 2350, but we will never hear the end of it.
“The first person to put up a coherent narrative wins the debate.”
LOL! The denialist side has been marked by extreme incoherence all along, and per your view, should likewise have ‘lost’ long ago! (Well, for some of us, that is indeed true.)
So much so that I wrote a lengthy song mocking them for it on my first album, back in 2020:
https://open.spotify.com/track/0ursieqYOROXv7zMWReQVi?si=0394e2486c6c46e9
Warning: it’s candidly the worst track I’ve ever released, in terms of recording quality. (Although it did have a brief ‘mini-viral’ moment, primarily in Brazil, last year–go figure.) So, to spare sensitive ears, here’s the lyrics:
“a coherent narrative”. Absolutely, you hit the nail. Not physics for a physical science but a coherent narrative. These narratives can be and have been crafted very nicely by the Fossils for a public with minimal education, low brain functionality for this stuff and (the real bonus creme de la creme) for what they really want, which is an outcome that they like and is not at all learning some physics.
That’s why the best of the Fossils are the ones that study debating skills. Knowledge of physics or any interest at all in learning any would actually be detrimental. Carefully crafting phrasings is the Fossil key. Like you stated with perfect insight “a coherent narrative”. Physics meh, maybe but really who cares?
This is something I have very strong feelings about (sorry)
RealClimate is likely the premier scientific AGW blog. From the About… “We aim to provide the context sometimes missing in mainstream commentary on climate science.” Obviously there is strong critiques on papers, articles, blogs that you disagree with and that is fine and expected, but RC really has a tribal attitude.
In my opinion, failed predictions are, far and away, the greatest impediment to acceptance of the need to do more to reduce carbon dioxide emissions. RC needs to call them out when they happen, not rationalise them 2 decades later. Gavin says “… his results were discussed widely among relevant scientists at multiple workshops. As far as I recall, opinions were pretty sharply negative.”
If this is the case, and a high profile public figure in their Nobel acceptance speech quoted it, RC should have called it out then.
KW: In my opinion, failed predictions are, far and away, the greatest impediment to acceptance of the need to do more to reduce carbon dioxide emissions.
BPL: The greatest impediment to reducing CO2 emissions is that the fossil fuel industry and their supporters among rightists have created a massive disinformation campaign which has lasted more than three decades.
EA: I’d combine both statements and say the that the greatest impediment to AGW is that failed predictions, while perfectly understandable in any scientific endeavour, can be easily co-opted by the Fossil Fuel Industry (and all the downstream manufacturers and users of said industry) to sway a public that thinks that one wrong prediction means that the science can’t be trusted.
Where have you been for the last 30 years, Keith? Don’t they have public libraries there? You’re welcome to your idiosyncratic opinion, but better-read people agree with Barton. For example, Jane Mayer, author of 2016’s “Dark Money”, in 2019 said this in the New Yorker, whose strict fact checking is famous (https://www.newyorker.com/news/daily-comment/kochland-examines-how-the-koch-brothers-made-their-fortune-and-the-influence-it-bought):
If there is any lingering uncertainty that the Koch brothers are the primary sponsors of climate-change doubt in the United States, it ought to be put to rest by the publication of “Kochland: The Secret History of Koch Industries and Corporate Power in America,” by the business reporter Christopher Leonard.
The origins of the disinformation campaign by fossil fuel producers and investors, with intent to forestall collective intervention in their profit streams, were exposed in the mid-1990s by Ross Gelbspan, a Pulitzer-Prize winning investigative reporter (https://www.publishersweekly.com/9780201132953). Due to subsequent efforts by trained, disciplined investigative journalists, historians of science (e.g. https://www.merchantsofdoubt.org), and social scientists (e.g. https://cssn.org/wp-content/uploads/2020/12/InstitutionalizingDelay-ClimaticChange.pdf), the ongoing campaign of climate-change denial is n ow a matter of redundant public record. And it’s all been ruled legal by a packed SCOTUS. I, for one, don’t call it a conspiracy theory when it’s common knowledge, and it’s not illegal!
Not common enough knowledge, sadly. The denialist campaign succeeds by filling a pre-existing public information deficit with lies, half-truths and misdirection, overwhelming by sheer volume any verifiable facts and logic. It has fostered the growth of a billion-dollar industry, whose product is bespoke doubt. It exploits the willful ignorance and self-seeking credulity of a persistently large proportion of the American public. Loss of public trust in science, and rejection of the simple physics of anthropogenic global warming, has evidently been the goal of the disinformation campaign all along. Its profit-maximizing obscurantism has been highly successful so far, although the percentage of Americans “alarmed” or “concerned” about man-made climate change reached over 50% last year for the first time since 2009 (https://climatecommunication.yale.edu/publications/global-warmings-six-americas-fall-2024). We’re now 37 years after Jim Hansen’s Congressional appearance! It seems you really can fool some of the people all the time.
Thanks. A very helpful article.
Note: a typo I think in the first chart. Shouldn’t the units for the vertical axis be “million sq km”?
[Response: yes! – sorry! – gavin]
The problem with climate sceptics is that they attempt to demolish the scientific consensus without putting forward their own rival hypothesis. The reason is simple: they base their position on the null hypothesis, and this has been proven wrong by the data. I suggest this is one way of countering criticism of climate models.
Of course, the Al Gore tactic is another example of our old friend, the straw man argument. For those looking for a fairly comprehensive list of this and similar dishonest methods, there is an excellent website named ‘Cranky Uncle’. Students (and former students) may find this an attractive learning tool as it takes the form of an online game.
Rory, I don’t think you understand the proper role of ‘skeptics.’ It is not their job to advance a counter-hypothesis. At all. Ever.
Their job is to pick holes in yours. (Actually ours, but as a lukewarmer I get to jump from side to side depending on the topic. Lucky me.)
This was a big deal back in the day. It would have been nice for some more people to stick up for the science and call out the Gore/Wadham exaggerations at the time.
A reminder that ‘lukewarmism‘ is another form of denialism that underestimates AGW and its risk, as Dave Farina aptly detailed. This has been explained for years to lukewarmers such as Thomas Fuller, Dr. Patrick Michaels, Paul ‘Chip’ Knappenberger, and Dr. Matt Ridley. Yet lukewarmers still persist, despite their position running contrary to the evidence.
Someone should follow up with these lukewarmers to see how they address their position’s failed predictions:
There is another side to this. The 70% plunge in September Arctic sea-ice volume from 2001 to 2012 was no “wiggle” — it was a structural shock. At the time, causation and near-term trajectory were genuinely uncertain, which is why precautionary attention to fat-tail risks — including Wadhams-style blue-ocean warnings — was reasonable. Had the 2001–2012 slope persisted, an ice-free September would have arrived by the late 2010s. Instead 2013 delivered a brief rebound, but on top of a still-steep long-term decline. Calling that earlier collapse a mere fluctuation is hindsight bias, not science. We’re seeing the same rhetorical minimisation today over 1.5°C: 2024 exceeded 1.5°C for the full calendar year, but agencies minimise this by insisting on an unrealistic multi-decadal warming measure. Who was to know Arctic ice would have a ‘dead cat bounce’ in 2013? Critics can say I told you so after the event, but excessive caution due to fear of distortion by deniers is not justified.
We humans are very poor at stretching our minds. Most of us count time in the context of our lifetimes, and space in the context of what we can explore. We can’t do submicroscopic and we can’t do space, not really. Science fiction brings space into our living spaces, but it too is unrealistic; it creates a human fiction of survivability which is not real.
Now as to ‘most of us’ that’s another number we have trouble with. Some of us count us in limited ways as well.
I realize there are exceptions, but unfortunately the habit of intolerance intrudes even in the minds of the most imaginative and open minded, with few exceptions. Those who are tolerant are intolerant of the intolerant. The mind boggles, but it’s difficult to keep it open.
—
Well, the last paragraphs stretch the metaphor too far for the context. But polar ice melt is one of the areas where people try to put the genie back in the bottle by saying if it hasn’t happened in time we experience, it’s not going to happen. That’s just not true.
[Also, AI is not the answer. Computers can encompass a larger dataset, but they entirely lack ethics and judgment.]
Yes; there’s still “no there there” in AI–as Gertrude Stein wrote long ago about something entirely different.
[I’m not a scientist!]
“Most of us count time in the context of our lifetimes, and space in the context of what we can explore.”
The 1972 book “Limits to Growth” viewed this as a key ‘fact.” See Figure 1. Available here https://archive.org/details/TheLimitsToGrowth/page/n19/mode/2up (page 19)
A related theme is the push for people to be “better ancestors.” E.g., https://www.romankrznaric.com/good-ancestor
We know from finding the remains of cities beneath the waters of the Mediterranean, the remains of human habitation in Doggerland and more, that sea levels have been rising for millennia. Point being; is it really such a stretch to be suspicious about claims this is now entirely anthropogenic, these days? And yes, CO2 levels support that theory, but CO2 levels have been high before and the world didn’t come to an end (or maybe it did, the records are incomplete). Anyway, I’ll be delighted when the use of crude to make plastic, grease, kerosene, diesel, and gasoline comes to an end but in the meantime, I’m not parking my paid for gas-powered car, and because I don’t have the political power to make it happen, I’ve no choice but to keep buying Coke in 2L plastic bottles. Also in the meantime? I grow tired of Chicken Little going on and one and on how it’s my fault. Whom amongst us won’t hop a flight to visit grandma on the west coast? Whom amongst us has significantly changed their economic behavior in a way that impacts corporations and makes them stop producing ICE vehicles on their own accord? Me? I think smarter than having Angelina mouthing off against pollution it would be smarter to get movie producers to write thoughtful scripts that show ordinary people taking actions which collectively benefit us. That, versus preaching incessantly.
John Beech: – “…but CO2 levels have been high before and the world didn’t come to an end (or maybe it did, the records are incomplete).”
Modern humans (aka Homo sapiens) have only been in existence on planet Earth for the last 250-300 thousand years, and apparently only developed a capacity for language about 50,000 years ago.
https://en.wikipedia.org/wiki/Early_modern_human
The daily atmospheric CO₂ concentration at the NOAA Mauna Loa Observatory on 7 Mar 2025 was 430.60 ppm. This is the first daily mean reading above 430 ppm ever directly recorded at this location. The atmospheric CO₂ concentration has not been this high since the Pliocene Epoch, 5.33 to 2.58 million years ago, where the global average temperature was 2–3 °C higher than today, and global sea level was about 25 m higher then, compared with current sea level.
https://en.wikipedia.org/wiki/Pliocene
Professor Johan Rockström, Director, Potsdam Institute for Climate Impact Research, said:
“We have no evidence, whatsoever, that we can support in a dignified and responsible way, eight, soon to be nine billion people in the world as we know it, at anything above 2 °Celsius.”
https://youtu.be/h2VjdyqG-nY?t=1376
See also my Submission (#26) to the NSW Parliament Joint Standing Committee on Net Zero Future:
https://www.parliament.nsw.gov.au/lcdocs/submissions/91844/0026%20Geoff%20Miell.pdf
The world won’t come to an end (well, not for perhaps billions of years, when the Sun runs low on hydrogen nuclear fuel and likely swells to a red giant phase that may perhaps engulf Earth), but at the current rate of planetary warming, human civilisation is on the road to collapse well before the end of this century.
How about a bit of scientific compare and contrast on topic of area versus volume metrics of sea ice? Both types of graphs are presented in this post. As a lay person to sea ice science it is straightforward to understand quantifying sea ice area. Does quantifying the volumne of sea ice entail some broad brush strokes of point measurement interpolation? Tx