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Messages - 6roucho

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101
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 28, 2016, 12:40:20 PM »
Yes, winter still exists.   ;D
Winter is coming. 🐺

102
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 28, 2016, 08:09:54 AM »
I can't help but feel that's very good trolling by Feeltheburn. Area and extent both have the capability to increase by record amounts with so much open water, and any kind of return to seasonal temperatures.

As many have said on here before, water *will* freeze beneath the cold, dark skies of the Arctic winter, and will do so for many years to come. Once we have an ice-free Arctic, it seems inevitable that the re-freeze rates will be unprecedented, simply because the area to be re-frozen is unprecedented. To posit that as a 'recovery' is the kind of boldly misleading assertion that so-called climate skeptics like to make, with a sly wink to people who know better, and a straight face to the public gallery.

And of course that's how it will be spun, with 'recovery' after 'recovery'.

103
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 26, 2016, 01:15:20 PM »
To the fool with no understanding of the physical world or a firm grasp on historical contexts, all events are black swans.
In a limited sense that's true. Taleb posits three defining characteristics of a black swan event: • After the occurrence of the event, explanations are formulated making it predictable or expectable. • The event has extreme impact. • The event is unexpected or not probable. We might call events that are simply unexpected weak black swans. But we flap far from the sea ice!

104
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 26, 2016, 07:40:04 AM »

I don't know how that black swan got in the picture, it was not expected until 2040 at the very earliest.


It appears to these old eyes to be a stork, possibly ushering in a new age of climatic chaos. 8)

Black Swan Theory developed by Nassim Nicholas Taleb to explain:
1.The disproportionate role of high-profile, hard-to-predict, and rare events that are beyond the realm of normal expectations in history, science, finance and technology. and meteorology?
2.The non-computability of the probability of the consequential rare events using scientific methods (owing to the very nature of small probabilities).
3.The psychological biases which blind people, both individually and collectively, to uncertainty and to a rare event's massive role in historical affairs.
Although it doesn't seem that the decline of the Arctic sea ice is itself a black swan in Taleb's theory, since the existence of black swans is unpredictable, whereas the sea ice decline is widely predicted, and indeed considered to be a certainty everywhere except the denier blogosphere and conservative politics. I don't think a phase change in a complex system qualifies as a black swan event, even though the timing of such events is also unpredictable.

What the loss the of the Arctic ice could be is a *factory* for black swans.

105
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 25, 2016, 02:40:43 PM »
If CryoSat's observations are wrong (and note the observation lag) then ESA has wasted hundreds of millions of euros.
Even if they were "wrong" over sea ice (and they aren't), CryoSat is still totally invaluable for making ice sheet observations.
Also, the argument that they are right because of the cost of them being wrong is an appeal to authority. The likelihood and severity of risks are unrelated quantities.

106
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 22, 2016, 02:26:36 PM »
And it's the largest of all the direct physical feedbacks.

True, but without the sola input in the first place there would be no feedback....  ;D

It's complicated when you have inputs, sequestration, feedbacks and a shrinking cooling budget.

Stick a big enough solar shield up there and all the feedbacks in the world won't replace the lost energy.
True. Insolation is by far the largest forcing, being by far the largest provider of energy to the system.

107
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 22, 2016, 09:14:17 AM »
That water vapor graph is stunning. You shouldn't hide it behind a link. I've been looking for a graph like that for months because I know that precipitable water is up but I didn't know how much. Yes, that much more water vapor increases temperatures globally.
And it's the largest of all the direct physical feedbacks.

108
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 20, 2016, 09:45:38 PM »
i don't even like that site because it's slightly on the denier side
That's presumably why it published a combined index in the past, when that data obfuscated arctic sea ice losses. We should expect to see a sudden disinterest in such indices now in that community.

109
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 20, 2016, 09:42:44 PM »
It does not matter in the slightest for product quality whether wipneus is a homeless drug addict working under a bridge on a stolen handset or a distinguished physics professor at Amsterdam U using a personal supercomputer.
Well put. Crowdsourcing secondary research is a beautiful idea, because of its scalability. Science is ferociously good at filtering in the most useful outcomes.

110
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 14, 2016, 06:08:22 PM »
I got the graphs from Climate4you, but they are from Argo data. I doubt anyone would have changed Argo data, to make their point. The first one was labeled CircumArctic, as having read before how the Argo system works, it most likely could not be deployed in the Arctic proper.
Unfortunately climate obfuscation usually results from cherry-picking subsets, rather than changing data.

Can you describe more specifically how that applies. I am always looking for more information on ocean heating and if you have more detailed regional data, please share.

P.S. I never have tried to be an advocate for any particular site.
I don't have data in this case, Tigertown. It was a general observation, from a working mathematician in my case. Generally speaking, effective obfuscators (not you of course - I'm referring to Climate4you as a source of possibly 'massaged' results) cherry-pick by optimizing start and end dates for data ranges to produce favourable outcomes, and by picking subsets of data ranges favourable to their argument. It's a recurring form of dishonesty in fringe climate science, and can be very difficult to spot, and can find its way into popular and even established science. I certainly wasn't intending to criticize you.

111
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 14, 2016, 04:14:06 PM »
I got the graphs from Climate4you, but they are from Argo data. I doubt anyone would have changed Argo data, to make their point. The first one was labeled CircumArctic, as having read before how the Argo system works, it most likely could not be deployed in the Arctic proper.
Unfortunately climate obfuscation usually results from cherry-picking subsets, rather than changing data.

112
Arctic sea ice / Re: The 2016/2017 freezing season
« on: November 12, 2016, 08:56:45 PM »
All you have to do is get the y positions of the red and green pixels and calulate the difference.
However this doesn't effect the average temperature anomaly. Below are the results of the past 5 years:

Average Temperature anomaly(in K):
Year                  2011   2012   2013   2014   2015   2016
whole year           5.96   6.83   5.54   6.91   6.65   8.44
since refreezing   0.48   2.45   1.05   2.08   2.15   5.08

Thanks Tealight.  That's exactly what I was saying.  If you don't mind, how do you extract the y positions of the red and green pixels?

So the data say that the temperature anomaly for this refreeze season inside 80N is about twice as large as any other year in the past five (and 10X larger than the coolest year in the last five).

I programed this in Python using the image libary Pillow(PIL). With it I can read out a pixel values e.g. red=3 and green=4.  Then a simple "for loop" finds all red and green pixels with a specific x value and saves them in a list. Sometimes the red line has 2 or more pixels for the same x value (vertical line). In that case i took the average of all pixels. The rest is simple math like "green y value" minus "red y value" and divide the pixel difference by 7.4 to get Kelvin.

You could say the anomaly is 10 times larger than the coolest year, but you would exploit the law of small numbers. Like 1.0 is 100 times larger than 0.01.

I attched the raw data (in Kelvin) as a comma seperated file. You can just open it in Excel and specify "comma" as the seperator. Maybe you can create interesting graphs or make other investigations.
Unless I'm missing something, 1 is 100 times larger than 0.01, and the law of small numbers is a logical fallacy.

113
Arctic sea ice / Re: The 2016/2017 freezing season
« on: October 30, 2016, 07:13:34 PM »
These anomalies are not additive.

Although, who knows the effects of a record low maximum SIE in the Arctic at the same time as a record minimum SIE around Antarctica???
At the risk of being pedantic, the discussion was of temperature, and the record low maximum Arctic SIE wasn't at the same time as the record minimum Antarctic SIE. But their correlation is interesting.

114
Arctic sea ice / Re: The 2016/2017 freezing season
« on: October 30, 2016, 05:06:59 PM »
These anomalies are not additive.
Although they are averagable. A bipolar +4.115 is probably far from any recorded average.

115
Arctic sea ice / Re: The 2016/2017 freezing season
« on: October 27, 2016, 04:16:09 PM »
- sure, my use of the word 'infinite' is most probably a faux pas in someones book but what else is considered argument worthy of proper consideration?
"More"?

As in, Q: How many concern trolls can dance on the head of a pin? A: More.

116
Arctic sea ice / Re: The 2016/2017 freezing season
« on: October 26, 2016, 06:39:31 AM »
The logical conclusion from Hansen's model output is that an ice age is about to begin (surprise surprise!).
Isn't that a debunked denier trope?

117
Arctic sea ice / Re: The 2016/2017 freezing season
« on: October 10, 2016, 06:02:21 AM »
I think from time to time it's well worth to have a look at global sea-ice extent as well :-)

The southern hemisphere decided to copy the 2016 Arctic spring in terms of sea ice area  ;)
In the context of the Arctic spring, which was itself an outlier event, that's a very interesting graph.

118
Arctic sea ice / Re: The 2016/2017 freezing season
« on: September 20, 2016, 05:49:24 PM »
I hope some remnants of big block can hold on for a couple more weeks. If they do, then I expect them to seed ice growth in the Beaufort. If that happens, then ice growth should speed up significantly since it will be growing from different fronts.

As we approach nearly ice free conditions, "big blocks" of ice could be pushed to strategic locations around the arctic to seed ice growth. This should give the freezing season a head start, maximizing ice production in the freezing season. The more ice produced in the freezing season, the more "negative heat" we can store for summer.
So, these are attractors at the edge of chaos to use the popular parlance.

119
Arctic sea ice / Re: The 2016 melting season
« on: September 18, 2016, 01:35:24 PM »
At (what might just about be) the end of another momentous Arctic summer, I'd like to thank everyone here for a season of rich information and dazzling scientific source material. This is one of the best science forums on the Internet. It's a shame it's documenting the end of something so valuable, but it has to be documented, and the Internet is doing a job here, even when (especially when) there is strenuous argument. I've no doubt that what is posted on here (and on similar sites such as Jim Hunt's excellent greatwhitecon.info) will become an important part of the public record. It's certainly forming a part of my own lifelong education. Kudos.

120
Arctic sea ice / Re: The 2016 melting season
« on: September 11, 2016, 01:38:55 PM »
Jim Hunt & Co: I checked the dates for Oden's position and it seems to me that it was at and around the North Pole about August 20-22. The tweet was out at August 28 so my question is whether they actually was at the exact point 90oN at the moment the pic was taken?

Sorry if I seem to be stupid but I think this is such an important thing that we have to be 100% sure that they actually were at the North Pole. They may have found it easier to just post "North Pole" rather than the exact coordinates.

Best, LMV
Clearly true, but a few points really don't matter. It's a new [and moving] paradigm.

121
Arctic sea ice / Re: Ice free predictions and their uncertainty
« on: September 09, 2016, 03:29:04 PM »
Yes looking at the IJIS average over the years since the 80s the average used to be 6m2 then 5.5 then 5 now its in the 4s. At best we have 25 years left till no ice ...peobably way less. So by 2040 theres bound to have been a number of ice free Summers.

Here in Ireland we had our warmest ever September NIGHT.
20c. Normal nighttime here is 8c. I feel its the ever warming oceans that are driving up these temperatures.

Why is Antarctic staying so cold though?
Antarctica may be gaining ice, but it's still warming faster than anywhere except the Arctic.

122
Arctic sea ice / Re: Ice free predictions and their uncertainty
« on: September 09, 2016, 12:24:20 PM »
Surely predictability hinges on the nature of the decline? Will the ice melt out in a linear fashion, or will it undergo a state change? If it's a state change, then we can't in principle predict the timing of the event by extrapolating trends, since a non-linear event is characterised by divergence from historical behaviours.

123
Arctic sea ice / Re: The 2016 melting season
« on: September 09, 2016, 02:13:13 AM »
The latest from the denialists that I am seeing about the arctic is that thousands of years ago that the arctic was quite often ice-free and that we are just coming down from an unusually cold period. The second thing I'm seeing is that they are doing what they did with 1998 temperatures and draw a line from 2007 and say that there is no downward trend in extent, just natural variability.
The strange way in which denier theory changes to accomodate observations is like a parody of the scientific method.

124
Arctic sea ice / Re: The 2016 melting season
« on: September 07, 2016, 08:16:37 PM »
As ice melts on Greenland, the surrounding Sea Surface Temps get cooler.
But I'm not seeing Sea Surface Temps cool just because Arctic Sea Ice melts.
So it would seem to me that melting arctic sea ice is not cooling anything.
Aren't the thermodynamics (approximately) the same? The net endothermic effect simply reaches the ocean by a different method.

125
Arctic sea ice / Re: The 2016 melting season
« on: September 05, 2016, 03:24:13 PM »
Has mentioned that the remaining ice's shape bears more than a passing resemblance to Tombaugh Regio, "The Heart"?  The left side—Sputnik Planum—even has huge floating "icebergs", complex thermal convection, and huge areas of broken-ice chaos instead of the CAA.  It is A LOT colder, however  :o

https://en.wikipedia.org/wiki/Tombaugh_Regio

Back to lurking now . . .
Science rocks!

126
Arctic sea ice / Re: The 2016 melting season
« on: September 01, 2016, 10:46:17 AM »
Strikingly beautiful patterns of ice in the water, if disturbing.
Fractals.

127
Arctic sea ice / Re: The 2016 melting season
« on: August 25, 2016, 10:18:48 AM »
The models are showing this monster recurving into Siberia and eventually ending up into the Arctic... with a similar event possible re: Gustav on the Atlantic side. I wonder if this results in our penultimate GAC of the season?
Ultimate, we hope! If there are more after this then it starts to look persistent.

128
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 01:22:32 PM »
Dunning-Kruger effect.

I thought this had to be shared:

Quote
The phenomenon was first experimentally observed in a series of experiments by David Dunning and Justin Kruger of the department of psychology at Cornell University in 1999. The study was inspired by the case of McArthur Wheeler, a man who robbed two banks after covering his face with lemon juice in the mistaken belief that, because lemon juice is usable as invisible ink, it would prevent his face from being recorded on surveillance cameras.

129
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 20, 2016, 08:38:20 AM »
Self-aggrandising posts are fine if they're brief. Posts that make personal criticisms tend to act as low-pressure cannons.

130
Arctic sea ice / Re: The 2016 melting season
« on: August 19, 2016, 09:20:35 AM »
"We have created an ocean where there was once an ice sheet. It is man’s first major achievement in re-shaping the face of the planet."

https://www.theguardian.com/commentisfree/2016/aug/18/ice-scientists-arctic-ice-disappearing-reduce-emissions-peter-wadhams

Although the article conflates ice-free with no ice at all.

131
Arctic sea ice / Re: The 2016 melting season
« on: August 19, 2016, 07:38:37 AM »
That would make bbr "Justified" like Raylan Givens
Indeed. I think everyone agreed that in the event of a GAC2016 the ice was either toast or nearly toasted, but the precise form of a bifurcation (or trifurcation) would be excellent prescience.

132
Arctic sea ice / Re: The 2016 melting season
« on: August 14, 2016, 04:47:57 PM »
Just trying to get answers without undue bias.

In which case I suggest you pose your questions without using material from known biased sources. Here's the output of an alternative implementation of HYCOM/CICE. Do you prefer GOFS or DMI? Which do you suppose best represents "reality"?

If we are to accept this model as an accurate portrayal of thickness, what should we expect to be the result from a persistent cyclone that lasts up to 7 days in an area of highly fragmented ice that is no more than a meter thick?
Do we have metrics on such a storm, apart from GAC2012?

133
Arctic sea ice / Re: The 2016 melting season
« on: July 18, 2016, 04:10:44 PM »
Enough of one particular chunk of ice.

For the avoidance of any doubt the BB split is even visible on AMSR2, as is much else:

thanks for another confirmation and i find it very "interesting" the nicest word i can find, how some people permanently even deny sat-images if things don't fit in their thinking pattern and compare today with 15th of July images after it was clearly documented (narrowed down) when it broke and that it's broke. now since this can be verified and sooner or later everyone has to believe the obvious, with other topics in here the same is ongoing, just choosing the days or week that fits there arguement while after certain discussions are ongoing since more than a month now we're still intermittently going back and forth between lowest and third lowest, mostly first or second, despite all the bad momentums and whathaveyou.

that said the worst for this year is still to come should the winds add more to it and the heat in the system delay the re-cooling onset.
I didn't read the discussion that way at all, magnamentis. I saw an interesting and instructive scientific argument, your posts included. I certainly know more by reading it.

134
Arctic sea ice / Re: The 2016 melting season
« on: July 14, 2016, 04:23:31 AM »
Yes Slater doesn't consider insolation, because his model is a statistical model based on regression. He mentions this on his SIPN report and on his website with the most up to date data.

Quote
These are probabilistic projections of sea ice extent. I use a very simple regression/projection method based on prior years and assimilation of the latest data - it's not the most sophisticated method but it does have a fair degree of skill.
Website:
http://cires1.colorado.edu/~aslater/SEAICE/about.html

SIPN report:
https://www.arcus.org/files/sio/25659/sio-2016-june_slater-persistence_0.pdf

In my opinion regional forecasts more than 14 days ahead are unreliable anyway because winds can push ice a few kilometers a day and change the distribution significantly.

Yes, I read that. I'm just not convinced by your explanation. I understand that a statistical model doesn't usually look at physics directly (I'm responsible for a statistical model in finance, for my sins) but the strength of statistical modelling is that it captures physics by proxy, in the observed behaviour of systems. Any model that predicts a melt season must (at least by proxy) incorporate insolation.

The problem this model has with the Hudson *might* mean he doesn't include the insolation effects of changes of latitude but absent a look at the code, my bet would be on something more subtle.

Bear in mind that I have no information about Slater's model beyond what I can glean from the few words in those links.

135
Arctic sea ice / Re: The 2016 melting season
« on: July 13, 2016, 07:18:45 PM »
So Slater's model doesn't take into account variation by latitude and thus insolation? That suggests it can't be used to make regional forecasts at all.

136
Arctic sea ice / Re: The 2016 melting season
« on: July 13, 2016, 09:07:34 AM »
That's all true, and there might be a phase change, as Professor Wadhams has argued, but we have no way of predicting the timing of such an event. One day soon the ice might split apart, and be melted in the warm waters of the north Atlantic, and no one here will deny that's happening. In the meantime, people will continue to observe the real state of the ice.

I think people's main argument with Bbr is about what the real state of the ice is, and Bbr's specific predictions of what will happen this year.

137
Arctic sea ice / Re: The 2016 melting season
« on: July 13, 2016, 07:39:09 AM »
As a counterpoint, 2012 depended on a very low efficiency mechanism to achieve its record.  ;D
Low efficiency but high energy: 6.0 x 10^14 Watts for a typical hurricane according to NOAH's Hurricane Research Division. That number's a proxy obtained by measuring the total amount of energy released by the condensation of water droplets.

"This is equivalent to 200 times the world-wide electrical generating capacity."

http://www.aoml.noaa.gov/hrd/tcfaq/D7.html


138
Arctic sea ice / Re: The 2016 melting season
« on: July 11, 2016, 05:18:17 PM »
What do you define the ongoing climate catastrophe as? If it isn't catastrophic then I don't know what planet you live on.
I'm sure many on here would agree that the problem we face with climate is a catastrophe, but to describe individual processes as catastrophic, they should at least be outliers, and compared to recent years, this year's melt simply isn't. It was for a while, but weather put a cap on it. It might be again, if weather intervenes.

Not all members of the catastrophe set are catastrophic.

139
Arctic sea ice / Re: The 2016 melting season
« on: July 09, 2016, 11:02:38 AM »
This is completely off-topic, and posted purely for entertainment, but this image of ventrical flow in the brain of a mouse has an uncanny resemblance to the Arctic.

140
Arctic sea ice / Re: The 2016 melting season
« on: July 07, 2016, 06:08:30 PM »
I can't help but feel that at least some of the sudden antagonism on here is trolling. This is the last place in the world to find denier sentiment or systematic mis-estimation of trends.

141
Arctic sea ice / Re: The 2016 melting season
« on: June 30, 2016, 02:33:27 PM »
The effects of reduced solar activity on temperature is small compared to normal variation: perhaps .1deg over an eleven-year solar cycle.

True but it has a larger impact on Insolation.
Does that mean the predicted minimum will have a mitigating effect on sea-ice melt over the coming years?

142
Arctic sea ice / Re: The 2016 melting season
« on: June 30, 2016, 07:09:28 AM »
Maybe this is the reason, that the melting has slowed down?

http://www.vencoreweather.com/blog/2016/6/23/1015-am-the-sun-goes-blank-again-during-the-weakest-solar-cycle-in-more-than-a-century
The effects of reduced solar activity on temperature is small compared to normal variation: perhaps .1deg over an eleven-year solar cycle.

143
Arctic sea ice / Re: The 2016 melting season
« on: June 29, 2016, 03:44:28 PM »
Quote
Temperatures in the Beaufort are not remaining at 0, but are discernably rising, if you look at the SST charts on Neven's graph page.

I really think there should be a study on the distance ambient ice needs to be on average to be conducive to ocean temperature rise above the melting point of ice.
Can't this be solved in physics, by a heat conservation equation?

144
Arctic sea ice / Re: The 2016 melting season
« on: June 27, 2016, 07:11:07 AM »
@ bbr2314 you show that massive transport toward the Atlantic precisely when the very same model you use indicates almost no export to Barentz or Fram for the coming days.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrfnowcast.gif
 Is your map is based on a longer range prediction, or on a hunch?
The red lines sorry don't make any sense to me. The drag induced by that supposedly sinking boat is insinificant to wind pull. Didn't we notice the effect of past storms?
@ Tigertown iirc the state of the ice at the end of the melting season varies much from season to season.
My map is based on what's happened over the past month... the export may not occur continuously but it has been ongoing. The drag/'red lines' would be because the volume of the ice in motion is so significant and something has to replace what has been displaced (i.e. open water)
Please excuse my ignorance of the physics, but why should displaced ice have to be replaced by ice from elsewhere? Can't it simply remain as open water? Assuming, of course, that the forces that "split" the ice aren't acting equally on the adjoining ice, but then we wouldn't have a split.

145
Arctic sea ice / Re: The 2016 melting season
« on: June 25, 2016, 05:35:09 PM »
Could that be a ship, JayW? It seems too fast for ice but too slow for an aircraft.

I think VIIRS resolution is 750m but I'm not 100% sure.  So it would have to be a half mile long ship to show up...
It would presumably have to fill half that, so a Nimitz class aircraft carrier or a tanker.

146
Arctic sea ice / Re: The 2016 melting season
« on: June 25, 2016, 03:12:29 PM »
Could that be a ship, JayW? It seems too fast for ice but too slow for an aircraft.

147
Arctic sea ice / Re: The 2016 melting season
« on: June 23, 2016, 05:07:04 PM »
Very impressive display of beating your chest and throwing your feces at others there, FTnioli. I'm sure if Jane Goodall studied sea ice she'd find much to study here.

148
Arctic sea ice / Re: The 2016 melting season
« on: June 21, 2016, 08:20:07 AM »
while a 2 dimensional floe pattern may leave less gaps than 3 dimensional dirt

In packing terms, a sphere occupies .666... of the container space of a circle. Devilish.

149
Arctic sea ice / Catastrophe bonds
« on: June 19, 2016, 08:02:18 AM »
Catastrophe bonds

One way of investing directly in catastrophe risk is to trade cat bonds. These are debt instruments in which the issuer's obligation to pay interest or repay the principal is deferred or forgiven in the event of the catastrophe occurring1.

In our case, we could issue a cat bond that triggers in the event of < 1m sq km of sea ice extent. (That's called a parametric trigger, and it's what we want because it's not linked to an actual loss.) The sooner the Arctic goes ice-free then the more money we make. After a certain time we start to lose money, and unless we've hedged then our losses could continue until all our capital is gone.

Who would buy such a thing? Speculators. Investors who think our risk analysis is wrong. Insurance companies, since we're effectively requesting to be insured against the event happening, but by way of a security instead of an insurance policy.

A typical cat bond has three parties: a sponsor (in this case us), an investor who provides the capital, and a special purpose vehicle (SPV) that holds the collateral on behalf of the investor and shelters the capital should the sponsor go broke. We'd have to have substantial capital to be taken seriously enough for anyone to buy them from us.

A bond is most profitably issued by a creditworthy entity. The composition of sponsors in the cat bond markets is approximately: 60% primary insurance companies, 25% reinsurance companies, 10% government entities, and 5% large corporates. Why would anyone trust us to continue paying interest? They don't really need to. The risk of us defaulting would be priced into the yield of the bond. If we default then they get their money back.

A more practical alternative might be to short sell existing bonds. The principle is the same as shorting any other security. You own less than (i.e. are short of) what you promise to sell in the future. So you might contract with someone to sell them $1m of cat bonds at todays price in a year. The catastrophe becomes more likely so the price falls, or the cat happens and the bonds are worth nothing. Or nothing happens and you have to go trade some bonds, potentially at a loss.

The difficulty is finding suitable bonds to short. No one has ever offered sea-ice bonds as far as I can see, unless it has happened in private. An ice-free Arctic certainly seems like an insurable event, since it could adversely affect markets, so it's possible that happened.

For our purposes, sea-level rise could be a usable proxy, since sea-level rise is coupled to sea-ice melt, not in the sense of one leading to the other, obviously, but in the sense of both being caused by warming. Thus we can bet on sea-ice indirectly by betting on sea-levels. And sea-level risk is unambiguously real, and thus insurable. But I can't find any sea-level bonds either. I suspect this is because catastrophe bonds typically offer protection over a three-year period. No one offers cat bonds over the long time periods needed for sea-level rise to trigger loss-related bonds' defining events.

Obviously, sea-level risk is abstracted from sea-ice risk by time as well as by Archimedes' principle. What we'd be betting on is that the conditions that caused an early melt of the Arctic would then lead to an early melt of land ice and thus faster sea-level rises than models predict. But this would take time to play out.

1www.jana.com.au/wp-content/uploads/2012/04/Capital-Markets-Jan-20121.pdf

[Edit: cat bonds are intended as insurance against real-world events such as hurricanes. The kind of speculation we're engaging in here might be considered immoral, like speculation in sub-prime in the run-up to the GFC might have been, but I have nothing to say about that. It's a choice for investors to make.]

150
Arctic sea ice / Re: Gambling on The Ice
« on: June 19, 2016, 07:26:34 AM »
An interesting snippet. Who sets the market for catastrophe risk? These estimates are supplied by third party risk consulting firms, based on modeling. The three main firms are AIR Worldwide Corporation (AIR), EQECAT Inc and Risk Management Solutions (RMS).

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