Comments on: Nothern Hemisphere Sea Ice: How’s it going?

By: Joe Hunkins

Joe Hunkins — Tue, 10 Feb 2009 00:13:11 +0000

Checking in to note that Nick Barnes won the minimum sea ice extent bet last year ( 2008) when the arctic ice extent fell below 4.01 million sq kilometers per Cryosphere today.

Nick and I are repeating the bet for 2009.

By: lucia

lucia — Wed, 17 Sep 2008 18:51:33 +0000

Fred–
It’s the number that will appear in this table:
http://arctic.atmos.uiuc.edu/S......1870-2007

By: Fred Nieuwenhuis

Fred Nieuwenhuis — Wed, 17 Sep 2008 18:49:36 +0000

Which dataset is being used for the bet?

By: lucia

lucia — Mon, 15 Sep 2008 13:34:26 +0000

Petro–
Do you consider Atmoz a denialist?!

By: Petro

Petro — Mon, 15 Sep 2008 13:31:15 +0000

So, it seems to be the case that all the denialists lost their bets. What a surprise…

By: Nick Barnes

Nick Barnes — Mon, 04 Aug 2008 21:39:07 +0000

OK, Joe, let’s do it over for 2009. Specifically: If Cryosphere Today reports a 2009 minimum area of more than 4.01 million square kilometres, I’ll pay you 50 euros. If Cryosphere Today reports a 2009 minimum area of less than 4.01 million square kilometres, you’ll pay me 50 euros.

By: Joe Hunkins

Joe Hunkins — Mon, 04 Aug 2008 05:30:25 +0000

Nick I’m happy to repeat our current exact bet for 2009 using the 4.01 number as measured by Cryosphere Today. Just reply here within a week. I’m also very interested in what conditions you think we’d need to see to say we’ve reached an NH ice “tipping point”.

By: Nick Barnes

Nick Barnes — Fri, 01 Aug 2008 07:33:03 +0000

I based that on my perception that the area anomaly line had settled down at around -1.3 Mkm^2. That has continued since (today’s number at CT is exactly -1.300 Mkm^2). The long-term average minimum area is around 5 Mkm^2, so if the anomaly is still -1.3Mkm^2 in September, we’ll see a minimum area of around 3.7 Mkm^2.
I am Nick.Barnes@pobox.com.

By: Joe Hunkins

Joe Hunkins — Fri, 01 Aug 2008 05:45:00 +0000

Nick glad you are checking in over here – my email FYI is jhunkins@gmail.com

You are now estimating 3.70 on what basis – are you extending the current line forward to a date in mid August?

By: lucia

lucia — Thu, 10 Jul 2008 16:10:46 +0000

Nick– You guy who do the real money bets must enjoy betting more than I do!

By: lucia

lucia — Thu, 10 Jul 2008 16:08:37 +0000

Nick– If you were going for 50%-50%, you might have found a decent dividing line. Someone would need to do some statistical modeling to try to estimate what they think is the 50-50 dividing line for ice area, but just eyeballing, you can’t be ridiculously far off.

OTOH, had you bet using a different definition for the amount of ice, you might have been sucked into a bad bet!

By: Nick Barnes

Nick Barnes — Thu, 10 Jul 2008 15:37:52 +0000

Oh, and I see that Joe proposed a repeat of our 2008 bet for 2009. I'm sorry not to have seen that at the time (blog threads are a singularly useless medium for having a conversation). I'm certainly interested in that, if Joe is still ready to bet. Maybe we could make it a sliding scale, as I suggested to Jim Cripwell:

1 euro per ten thousand square kilometres either side of 4.01 million, up to a maximum of 50 euros (e.g. if it’s 4.45 million, I pay you 44 euros, if it’s 3.85 million, you pay me 16 euros

By: Nick Barnes

Nick Barnes — Thu, 10 Jul 2008 14:58:57 +0000

The whole idea of my bet was to find a point which seemed about 50/50. I originally proposed it to Jim Cripwell, who was posturing about sea ice bets. However, Jim refused to take up a wager for actual money. Then Joeduck stepped in. At the time, when last winter's freeze was setting in and the anomaly was predictably heading back towards zero, a number of people on the sceptical fringe at RC were arguing that the 2007 melt was a total freak event, and that 2008 would see numbers in line with the long-term average. My view was that the 2007 minimum might well have been a one-off but there was a clear downwards trend, and that even if the 2007 weather conditions were not repeated in 2008 the shortage of multi-year ice would be bound to show up in the 2008 numbers. So I picked a cut-off which I hoped would be appealing both to myself and to a sceptic: that the 2008 minimum area would be lower than any year before 2007 (the 2005 record was 4.01 Mkm^2). My actual expectation then was maybe 3.75 Mkm^2. The current numbers suggest a minimum area of around 3.7 Mkm^2. The current maps suggest it might be much worse than that, as the zone between the Beaufort Sea and the pole looks ripe to melt out completely. I am also on the low side of a £10 bet with Stoat, that 2008's CT minimum area will be less than 2007's. I very much hope to lose that one.

By: Joseph Hunkins

Joseph Hunkins — Tue, 08 Jul 2008 20:53:07 +0000

Thx Lucia, but Nick did note that 2007 was about 3 million sq km so I think we both agreed on the measure of (c) and therefore I’ll just have to keep my fingers crossed.

Unfortunately I now realize that I failed in my quest to find some bettable measure of “tipping points”. There is so much talk about those even though I’d argue the tipping point stuff is mostly an unreasonably alarmist way to view the data, which tends to show a very small, gradual warming trend and suggests no global tipping points are near.

By: lucia

lucia — Tue, 08 Jul 2008 19:53:56 +0000

Joseph….
Your bet is confused.

It uses the word area which is smaller than extent. Then your bet says the minimum area last year was just above 5 million square km.

The minimum ice area last year was just above 3 square kilometers. This corresponds to (c) above. You can see the graph here: http://arctic.atmos.uiuc.edu/c.....t.area.jpg

I can’t read the graph very well, but a bet of 4 for the minimum area is risky! But, if you were looking for a 50%, 50% chance of winning, maybe 4 is fair.

The JAS extent was above 5 million square kilometers. That’s here:
http://arctic.atmos.uiuc.edu/c.....0-2007.jpg

If you’d bet 4 million square kilometers for the JAS ice extent you’d have a very good chance of winning!

On this blog, we have been betting on the JAS ice extent. So be careful with your bets out there!

By: Joseph Hunkins

Joseph Hunkins — Tue, 08 Jul 2008 19:43:06 +0000

Lucia FYI here are the conditions of my bet with Nick Barnes over at RealClimate, as outlined by Nick over there:

The 1979-2000 average minimum is a little over 5 million square kilometres. 2005 was a record low of 4.01 million square kilometres; 2006 was not quite so low; 2007 was around 3 million square kilometres. I propose a cut-off number of 4.01 million square kilometres: the 2005 number. That is, I’ll put money on the 2008 minimum being lower than any previous record except 2007.

If Cryosphere Today reports a 2008 minimum area of more than 4.01 million square kilometres, I’ll pay you 50 euros. If Cryosphere Today reports a 2008 minimum area of less than 4.01 million square kilometres, you’ll pay me 50 euros.

By: Joseph Hunkins

Joseph Hunkins — Tue, 08 Jul 2008 18:14:33 +0000

Lucia – thanks for another lesson in Arctic sea iceiness. We agreed to use the data on the chart from “Cryosphere Today” but I’m not sure if that is b or c.
The 4.01 came from the record prior to the 2007 record which was from 2005 I think?

Is there a daily measure of b or c available online?

By: lucia

lucia — Mon, 07 Jul 2008 17:23:31 +0000

Joseph–
Does your bet include precise specification of the metric and reporting agency?

Some people are betting on any and all of the following, each of which is different:
a) The JulyAugustSept sea ice exetent as reported at the Cryosphere. (That’s what we are discussing here. It’s an average, and likely to be the highest number.
b) The actual minimum summer ice extent. The minimum will happen in September, and will be lower than the average of JulyAugustSept.
c) the sea ice area minimum. This is smaller than the ice extent, because if there are whiles, they subtract that area out.

So… whether 4.0 is a safe bet or not depends on whether your bet is (a), (b) or (c). Go back and check the metric. If the metric is not specified, you will have a lot of arguing at the end of the summer.

By: Joseph Hunkins

Joseph Hunkins — Mon, 07 Jul 2008 17:15:55 +0000

Over at RealClimate I made a real money bet of 50 Euros that the Arctic sea ice minima will be over 4.01 this season – think I’m going to win that? I thought all the talk of “tipping points” over there was probably alarmist, making this a good bet, but I now understand that the hugely anomalous 2007 minima makes it hard to return to the normal slightly downward trend within a year. Yet I think I still have a good shot?

By: KuhnKat

KuhnKat — Fri, 04 Jul 2008 19:15:54 +0000

See what happens when the Elves start using nuclear plants to power the toy shops and heat the buildings?? The waste heat has to go somewhere!!!