In Denierland I compiled a list of predictions of the disappearance of Arctic sea ice. You won’t have seen this unless you delved into the notes and references for Chapter 4. With the passage of a couple of years I thought it was about time to resurrect the list, search for any more predictions and to check whether any predictions have been falsified in the intervening year (the last update before publication was 2019 for predictions and 2020 for results). I’ve only managed to find two more recent predictions that were bold enough to put a date on things, both made in 2020.
Two predictions are at risk of being falsified in the coming September: Tim Flannery’s of 2007 (and that is giving him a lot of leeway) and James Anderson of Harvard’s.
The following explanatory text comes from Denierland:
Several of these predictions (and both those dating from before 2005) were sourced from ClimateChangePredictions.org. The rest have come from news searches on the internet. In some cases I have had to use a tad of judgement in giving the date for the loss of ice, when statements like “in the next two decades” are used. An asterisk in the “Ice Will Be Gone By” column indicates that a form of words allowing some wriggle-room was used: “could be gone by…” etc.
“The study analyzed recent results from 40 of the latest climate computer models and involved 21 research institutes from around the world.”
The following paragraphs are repeated verbatim from Denierland; I would have put things a little differently if writing them today, but I didn’t want to edit them:
What is the point of all this? Not to prove that making predictions is hard, especially about the future. Instead, I want to highlight that predictions are actually very easy to make, and for some reason, predictions made by scientists have a certain currency beyond the SWAG of a typical human on the street. Learned folks have credentials, and their predictions are to be respected, or at least used to generate clicks on the internet. Strangely when predictions expire, the scientists who made them are not called back to ask why. Indeed when predictions expire, some regulars just make a new prediction a few years down the road.
“How does one prepare their children for the extintction [sic] event we are witnessing? How long before it impacts us all to the point where it is a matter of survival? Is it best to be ignorant at this point and not tell them that [they] will not see their adulthood?”
The3Js, in a comment beneath the 2013 article at Arctic News.
Well, The3Js’ children are now 7 years (2022 update: 9 years) older, so it looks as if climate change might not preclude them reaching adulthood after all. The following is from a BBC article in 2012:
Professor Peter Wadhams, from Cambridge University, told BBC News: “A number of scientists who have actually been working with sea ice measurement had predicted some years ago that the retreat would accelerate and that the summer Arctic would become ice-free by 2015 or 2016.
“I was one of those scientists – and of course bore my share of ridicule for daring to make such an alarmist prediction.”
But Prof Wadhams said the prediction was now coming true, and the ice had become so thin that it would inevitably disappear.
Turns out that the good professor was wrong, but his credentials meant that he could keep giving alarming predictions over and over (see the table above). Only one that I can find has yet to expire, from two years after the above quote, pushing the ice-free date back to this year, 2020. (Oops, looks like that was a fail too.)
I found the following quote in one of the cited articles, and found it so remarkable that I reproduce it here.
“Sometime in the 2030s or 2040s time frame, at least for a few days, you won’t have ice out there in the dead of summer,” said Dr John Walsh, chief scientist of the International Arctic Research Centre.
From the 2016 Guardian article in the table above.
To use the phrase “dead of summer” is amazing, simply because the summer is the only time there is visible life in the high Arctic.
Finally, here is the latest update on sea ice minima, as of September last year:
If we extrapolate the line beyond the range of the data (usual caveats apply), it hits 0 in about 60 years. For reasons that will not be gone into here, “ice-free” generally means when there is less than 1 million square km of ice left. So that would be in about 40 years. The scatter around the line of course means that, ceteris paribus, we might hit an ice-free weekend one day in September in about 25 years.
Featured image: The most recent Arctic sea ice minimum extent, 22 September 2021, from NASA worldview terra/aqua and JAXA’s AMSR-2 instrument.