Sea ice – and now for something just a tiny bit different

[Update: see comments. We’re having some dispute about whether to bet on the monthly averages (the scientifically respectable thing to do) or daily min (the wildly exciting popular choice). I need to bother work out the numbers. Until then, you’ll have to be patient (2011/3/31; I’ve adjusted the posting date from 2011-03-22 to push this to the head of the queue)]

But not very different. Neven reminds me, again, that I promised to put up a slightly longer-term bet; see This year’s sea ice and in particular this comment and reply.

Neven offers:

I’d be willing to bet 50 euros on a record low within the next three melting seasons. And with record low I mean absolute daily minimum extent based on data as reported by IJIS.

Well, we need not worry about the amount for the moment, instead I’m trying to set the terms of the bet (for amounts, it will be word-of-honour for anything down at the “trivial” end and something a little more formal if you want to go above £1,000).

I dislike daily values; monthly means are better, and are less likely to be influenced by oddities, and more likely to be consistent between series. I’m happy to use IJIS though.

Otherwhere, Gareth predicts the end of summer sea ice in 5 years, based on extrapolating thickness trends, and I’ve taken the liberty of ripping off his image. This I don’t believe at all, and if anyone is prepared to bet on no (or essentially no) summer ice by 2016, I’ll be very interested.

Anyway, here is the pic I’m basing my judgement on:


(this is a mod of one from a previous post). Black line is just the obs. Green line is trendline using all the data that far (so it is a straight line into the future). The other lines are a bit more complicated, and I keep forgetting what they are: the blue line is the trend, using data only as far as the point on the x-axis, but taking the trend to where it would be in 2010. The red line is the same as the blue, but using only the 10 years before that point. And lastly the one that matters is the purple line, which is the trend to 2013, again using the previous 10 years, though displaced off (so the point at 2013 is drawn from 2001-2010 data; the point at 2012 from 2000-2009, etc).

Using last-10-years is being pessimistic (or from my point of view, erring on the safe side) but based on that, the chance of something beating 2007 and setting a new record low within the next 3 years (including 2011) seems quite good. So I’m not betting on that; after all, remember that what we’re aiming for is a bet that both sides regard as a sure-fire win for them :-). So, based on those lines, and needing the usual error margin of 0.5, which I’ll multiply by sqrt(3) since there are 3 years, I think a “fair” (ish) bet would be on the ice going below 3 (whatever the units are, I forget) any time during the next 3 years. Anyone interested, or care to dispute my numbers?

Days vs Months

[Added in update, 2011/3/24 22:00]

Clearly, people would rather be betting on a record *daily* low, whereas I’d rather think in terms of monthly averages. My justification for that is that it reduces the statistical noise, and so allows for smaller uncertainty margins. Though I admit I haven’t looked at the day/month differences. I suspect that really it shouldn’t matter too much: ice can’t vary much on a daily basis; it isn’t possible to have some vast down-spike on just one day (barring an unlikely compression event). Conversely, if you believe in a record daily low, then you ought to believe in a record monthly low, too.


* IJIS / JAXA ice extent which DA notes (prematurely, but probably correctly) has just peaked this year.

Alderley Cliff

A weekend in the Peaks for family purposes, and to our great surprise just around the corner was a rather nice cliff. It is very tucked away and rather takes you by surprise. Here’s the google maps link. If you scroll out a bit you’ll see “Wheeldon Trees Farm holiday cottages” where we stayed, and which has a convenient footpath running down from the right to the cliff (and if you scroll out a bit further you’ll see the giant limestone quarry which shows up far better from above; on the ground you hardly see it). Just south – Longnor – is the Dove valley – beware: the pubs don’t open until 12.


So here is the cliff, or rather the central portion of it. Dots are the route, arrows are the belays, but I didn’t need to tell you that. “Miranda’s delight” is an HVD arete, that ends with a little duck L into the corner because the very top of the arete is compact and gearless; probably around VS to top out on the straight line. I suppose the rock must be limestone (it is an old quarry, now owned by the BMC, though curiously the BMC website doesn’t mention that), reasonably weathered and faded, not much polished. It seems to be a quiet venue; many of the lines could do with a bit of gardening. Out of shot to the far right there were more weeds and brambles, and a warning sign noting that it was an old quarry and that bit wasn’t necessarily considered safe. But out bit was much cleaner. When we were there it was very dry; after some rain it might get muddy. I know that route is HVD because someone showed us their guidebook, but I didn’t remember the real route name. w-by-dan-Aldery The children happily seconded the arete; with a rope above you it really isn’t hard. The pic to the right is by Dan Lane, who does climbing photopgrahy (see and does quite a good job of making me look heroic as I contemplate the steep arete.

Miriam’s downfall (S, 4a) is the obvious crack. From where I’ve taken the photo it is clear that the angle is fairly easy, but what you can’t see is that the other side of the corner forces you somewhat out of balance at about half height and above. Both routes have good solid trees to belay on. It is a nice route, just a little bit dirty and a little bit polished at some of the more obvious holds, but a pleasant severe and a good start to the “season” (I put season in brackets because I know I’ll be lucky to climb again this year :-().

What isn’t so obvious from these pix is that there is a good deal of rock elsewhere. Lets have a wider look:


The previous pic showed the rock roughly under the high point of the clifftop; from this pic you can see that the face on the L of the top pic goes up much higher. The lower part of that face is compact and looks Hard; but the upper tier (which you might reach up the HVD) looked more crack-y, but possibly less easy angled.

Anyway, a very nice little find I think, we’ll try to go back. We may have exhausted the easy climbs on the cliff – from there it looks to be VS and up, unless you top-rope.


av-yes-banner1 To a debate on the Alternative Vote, organised by Cambridge Labour party. I talked about AV a bit before when I was unenthusiastic. I’m still unenthusiastic (which is part of the Tories cunning trick I think) but certainly in favour.

The two debaters were John Denham MP (in favour) and Gavin Shuker MP (against). Both Labour. Neither presented a particularly strong logical argument for their view – in the case of the anti, presumably because there is no such argument. They tossed a coin for who went first (GS), had their 10 mins each, then 2 mins replies, then questions from the floor. I had to leave to go shopping after an hour, which was a shame, because I was interested (I can listen with my eyes shut you know). I haven’t been to a political meeting for ages, so that aspect was fun too.

I won’t rehearse the arguments in favour in detail here (you can find them at Yes! To fairer votes if you want). My own are (a) it will be good for the Green Party (b) and the Lib-Dems (c) and bad for the two-party system (d) and if we vote this down, we won’t get a chance of anything better for ages. None of those were particularly strong arguments in a Labour environment, the main argument used “for” was that it is a Progressive system for Progressive times and a Progressive party, and would lead to politicians having to broaden their appeal and be less identikit.

Oh, the brave Music of a distant Drum!

rubaiyat2 Omar Khayaam, sorry I can’t do the bold around “distant” in a title. I gave Hugo the popcorn on friday, but it didn’t really apply until today. It looks like the Frogs win the first strike award whilst Gaddafi gets the lying scumbag award. The end result of the Gaddafi-vs-the-West military fight is in no doubt; quite where that leaves the ground war is less clear. Probably in an Afghanistan-type situation, where we (well, the US in that case) bombed the Taliban so the Northern Alliance could take over. Only lets hope this time we don’t collude with the drug-dealers; as far as I can tell the rebels are much nicer than the NA.

Soundtrack: Flight of the pelican.

CIP makes various good points; that if we’d done nothing the rebels obvious next choice was Al-Quaeda (but we’ve averted that; good); that by waiting so long we’ve lost the chance to topple Gaddafi easily (sadly so; that leaves Libya badly shot-up and a lot of people pointlessly dead); and that by waiting so long, we’ve probably pushed all the doubters into a show of loyalty to the Dark Side (but hopefully they will be having another think now). But, assuming the worst isn’t true (the worst would be that the West actually wants a stalemate in Libya, because it fears the “example”, and is being leaned on by Saudi and Israel; entirely plausible, but probably not true) then I think the good guys are likely to win out.

Incidentally, I think this is starting to look good for Obama, possibly just by chance. By hanging back and leaving it until late we had the Arab League practically begging the West to intervene, Gaddafi was doing his best to act and sound like a mad dog, and that coupled with France and the UK leading the security council resolution meant that China and Russia found it awkward to veto. Shame about the Squareheads, though.

We’re so predictable

_51601556_rebeltank_ap As in, we start off bombing their air defences. Heavens knows how we’d get on against a clueful opponent. Fortunately the enemy in this case is both clueless and effectively powerless.

This is a picture of a tank. As it happens, a rebel tank. In case you’re wondering what it can do, the BBC has some insightful analysis: It offers high protection from small arms fire and carries a big gun (I’m being snarky of course, that is why you’re here, but the rest of the article is of value). Also interesting to see that Toyota seems to have cornered the market in “technicals” – the stuff-a-machine-gun-on-a-pickup-truck type stuff. They got a bad reputation for wanton violence a while back, but maybe these will feature in the Toyota PR literature.

Too much news

This, of course, pushes the Japanese quake and reactor off the top spot in the news league, which I’d say is a good thing. We can stop vacuously panicking about trivial levels of radionucleides and settle down to some decent war porn, and the Japanese can get started on rebuilding in peace; my best wishes to them.
Continue reading “Oh, the brave Music of a distant Drum!”

Nuclear Reactor Boy’s Tummy Ache

It is all explained here “in a calm rational scientific manner”.


* Japan nuclear threat: The tsunami is the bigger tragedy By David Spiegelhalter, Professor of the Public Understanding of Risk, Cambridge University
* Pakistan miners feared dead – for anyone who thought that coal was safe.
* Why Fukushima made me stop worrying and love nuclear power – George Monbiot
* Jurrassic Park is a triumph for dino theme parks: Build more dinosaur theme parks now!
* JEB on some back-of-the-envelope calculations of radiation risk

SB out(r)age update

ScienceBlogs say they’ve upgraded their Rackspace package in a hyper-whizzy way, which is supposed to have fixed all the problems with IP blocking.

If you’re still having trouble, err, and can’t read this message, err… ahem, or perhaps you have a friend, yes that’s right, or maybe you can read this from work or not from home, anyway, please mail the failing IP to

Apologies for all the inconvenience. When/if I ever work out exactly what was going wrong, I’ll let you know.

[Update: I’m pleased to say that I at least can now read / write SB from home.]


* My nipples explode with delight (me, when I didn’t know what was going on)
* On the DDOS attack on Scienceblogs (Tim Lambert, who after all is a CompSci and all to understand all this blather)