Bill, I read your response to Peter Ellis' post several times now, and I must admit that I have no clue what you are talking about.
Specifically :
- Which exact point is it that you 'understood' that Peter Ellis was making ?
- Why do you state that Peter Ellis was "misinterpreted" ?
- Which "phrase" from him was "taken on its own" and who did that ?
It would be nice if you could answer these questions, because what I see is that Peter Ellis is trying to downplay the fact that IPCC changed the definition of "less than 1 M km^2" to the much more restrictive (and scientifically unsustained) definition of "less than 1 M km^2 for 5 consecutive years".
Rob,
Apologies for any confusion I caused. On Friday, I was rushing out to see the Queen Stage on the Tour of Britain. (That's a cycling race, for the uninitiated.) As a consequence, I failed to take enough care in my wording, and, in particular, failed to be adequately explicit.
I'll try to make my position clearer, but that comes at the cost of a much longer post than I would normally contemplate.
Anyway, addressing your 3 questions...
Q1: "Which exact point is it that you 'understood' that Peter Ellis was making ?"
First off, I'll choose to ignore the quotation marks, as in 'understood'.
In Reply #861 to your #860 on the "2016 sea ice area and extent" thread, Peter made the following statement...
"The motive seems quite clear to me - try to get people to pay attention to the 5-year mean rather than individual years. The first individual year under 1 million will be definition be an outlier and is almost certain to be followed by a year above 1 million. For something as important as this, there needs to be a definition where the deniers can't turn around 12 months later and pretend there's a recovery. ..."Whilst I would have phrased the second sentence more along the lines of "... The first individual year under 1 million ... is likely to be followed by a year above 1 million", I do agree with the need to avoid the unwitting or unnecessary provision of ammunition. You remember as well as I do all the bollocks about a recovery after the 2007 - 2008 - 2009 minima. (
I don't make any claim as regards my understanding, or otherwise, of the motivation underpinning said definition change.)
Later, in Reply #42 of this thread, Peter stated...
"... Not sure if your Google findings help - they both come from after the report, at which point any competent scientist will be referring back to the agreed text to define the consensus view, and then explaining based on that. He [Prof Ed Hawkins] is doing basically the same thing as we are in this thread - pointing out that an individual ice-free year will, by definition, come earlier than five consecutive ice-free years (or indeed an ice-free 5-year running mean).
Might be worth checking with him, I suppose - but the larger point he's making is that the first single ice-free year is both completely unpredictable and largely irrelevant in scientific (rather than psychological) terms. Trying to forecast individual years is a mug's game."From these two statements, my interpretation was (and is) that Peter meant by the time the 5-yr running mean gets below the 1 million mark, there will be little scope for deniers to write it off as a fluke event - as happened in both 2007 and 2012.
As it happens, I don't actually agree with Peter, as the various machinations of the climate change denial machine are simply jaw dropping. We've seen outright denial that Arctic sea ice was declining; we've seen claims that that the levels seen post-2007 are comparable to those seen in the 1950's; and we're now seeing the groundwork being set for the future by claims that the Arctic was seasonally ice-free back in the 1920's. Revisionism in all its ugly glory!
Your 2nd and 3rd questions were...
Q2- Why do you state that Peter Ellis was "misinterpreted" ?
Q3- Which "phrase" from him was "taken on its own" and who did that ?
If you read Replies #43 and #44, the answers to these questions should be self-evident.
Archmid is correct in stating that a very low amount of ice in the Arctic is scientifically interesting. In fact, living in the UK, it's frankly fucking terrifying. The behaviour of the jet-stream is largely unpredictable at the best of times - that's why the weather is so ubiquitous in everyday conversations over here. However, that wasn't the point Peter was making, and, one of his statements
was taken out of context in #43. (Hence Peter's response in #44)
My Reply #46 was merely intended to inform Peter that I had not interpreted his words in the same way as Archmid.
However, I fully agree with Archmid's sentiments. Leaving aside the ice/albedo effect, as well as the impact of greatly reduced sea ice on the jet-stream, what really scares scares me is the impact on the Greenland Ice Sheet. The obvious factor is Sea Level Rise, but the real bummer (as far as winters in western Europe is concerned) would be if the AMOC reduces significantly. (Do I hear "Younger Dryas" anyone?)
In fact, I'm really horrified by the prospect that nothing, in terms of emissions control or CCS up-scaling/implementation, gets put in place until this ludicrously low value of 1 million sq kms gets surpassed. Long before we hit the 1 million mark, the planet will be experiencing conditions not felt since the Quaternary Glaciation took hold in the northern hemisphere. The very idea that 1.001 can be equated to business-as-usual, but 0.999 equates to some kind of wake-up call is a sad reflection on the whole sorry business.
That value represents the point at which the area is no longer described by 7 digits, as from then on, 6 digits would suffice. To the best of my, admittedly limited, knowledge, the only time the area in the Arctic Basin dropped below the 2 million mark was when it hit 1.8 in 2012. Therefore, setting an "ice free" definition at just 1 million sq kms for the entire Arctic, comes across as a
carte blanche to the denialist industry for the next few years - at least.
Rob, as to your final point, any question you have regarding Peter's supposed attempts to "... to downplay the fact that IPCC changed the definition of "
less than 1 M km^2" to the much more restrictive (and scientifically unsustained) definition of "less than 1 M km^2 for 5 consecutive years", I'm afraid you will have to direct toward the man himself.
For what it's worth, at no time have I garnered the impression that Peter was attempting what you suggest. In Reply #460 of the "sea ice area and extent" thread, Peter stated...
"
... The "five consecutive years" seems to have spread by a comedy of errors.
First, there's a bungled attempt at clarification in the figure caption on page 21. The intent of the sentence is clear from the graph- it plots the 5-year mean and draws a dotted line to show where the 5-year mean falls below 1 million - but the caption erroneously says this means 5 consecutive years below 1 million. ..."
As I've said above, my own view would be that the 1 million sq kms figure would be far better applied just to the Basin, not to the whole Arctic.