Discussing low sensitivity

Climate Sensitivity Single Study Syndrome, Nic Lewis Edition

So, Nic Lewis, who created a bit of news in the climate change blogosphere for coming up with quite  a low estimate of climate sensitivity, has actually got a paper published in a reputable journal.

James Annan, who truly has a tin ear for how fake skeptics will use his words when he is speaking about sensitivity, had already found some grounds for doubting parts of Lewis' approach, but a very detailed look at Lewis' work is now up at Skeptical Science. (See above.)

The comments following are worth reading too.

It certainly does not look like this should be taken as sweeping all other work on the issue away.

But watch the fake skeptics treat it that way.

Update:   this passage in the Skeptical Science article caught my attention:

In Figure 3, the PALEOSENS team also illustrates the amount of warming we can expect to see at various atmospheric CO2 levels, based on these paleoclimate studies, using several different approaches.  Doubling of CO2 from 280 to 560 parts per million results in close to 3°C global surface warming at equilibrium, when accounting for relatively fast feedbacks.  The paper also discusses various estimates of 'Earth System Sensitivity', which includes slower feedbacks that operate over thousands of years.  They estimate this longer-term warming in response to doubled CO2 would be closer to 7°C.

 There is very much a tendency for climate change skeptics to not notice how much of the discussion about climate change merely looks to what the situation is likely to be by the end of this century:  "Oh, sea level rise of 60cm over a century.  That's manageable."   There is inadequate discussion by scientists of the longer term consequences, if you ask me.

Also, a new paper in Nature Climate Change talks about land biosphere feedbacks:

Atmospheric concentrations of the three important greenhouse gases (GHGs) CO₂, CH₄ and N₂O are mediated by processes in the terrestrial biosphere that are sensitive to climate and CO₂. This leads to feedbacks between climate and land and has contributed to the sharp rise in atmospheric GHG concentrations since pre-industrial times. Here, we apply a process-based model to reproduce the historical atmospheric N₂O and CH₄ budgets within their uncertainties and apply future scenarios for climate, land-use change and reactive nitrogen (Nr) inputs to investigate future GHG emissions and their feedbacks with climate in a consistent and comprehensive framework¹. Results suggest that in a business-as-usual scenario, terrestrial N₂O and CH₄ emissions increase by 80 and 45%, respectively, and the land becomes a net source of C by AD 2100. N₂O and CH₄ feedbacks imply an additional warming of 0.4–0.5 °C by AD 2300; on top of 0.8–1.0 °C caused by terrestrial carbon cycle and Albedo feedbacks. The land biosphere represents an increasingly positive feedback to anthropogenic climate change and amplifies equilibrium climate sensitivity by 22–27%. Strong mitigation limits the increase of terrestrial GHG emissions and prevents the land biosphere from acting as an increasingly strong amplifier to anthropogenic climate change.

I'm not sure how much difference that makes to overall long term climate sensitivity estimates, but it sounds as if it might be new and significant.

The problem with droughts

Climate models fail to ‘predict’ US droughts 

It's a bit surprising to see that climate models are still not good enough to replicate US mega-droughts.

The results were puzzling. Although the simulation produced a number of pronounced droughts lasting several decades each, these did not match the timing of known megadroughts. In fact, drought occurrences were no more in agreement when the model was fed realistic values for variables that influence rainfall than when it ran control simulations in which the values were unrealistically held constant. “The model seems to miss some of the dynamics that drive large droughts,” says study participant Jason Smerdon, a researcher at Lamont-Doherty who studies historical climate patterns.

Other climate models tested by the team fared no better, he says. In particular, the models failed to reproduce a series of multi-decadal droughts that occurred in the southwest during the Medieval Climate Anomaly, a period between AD 900 and 1200 when global temperatures were about as high as they are today.

The problem may lie in the models’ inability to reproduce the cycling between the ENSO’s El Niño and La Niña phases, especially given that many scientists think that La Niña is the major driver of drought in the southwest. The ENSO “behaves much messier in the real world than in climate models”, says Jessica Tierney, a climate scientist at the Woods Hole Oceanographic Institution in Massachusetts who has investigated the role of the ENSO in East African rainfall variability². “We’re not sure how it has varied in the past, and we don’t know how it might change in response to climate change. This is really one of the big uncertainties we’re facing.”

In addition to their failure to reproduce El Niño and La Niña, existing models do not fully capture other factors that influence rainfall, such as clouds and vegetation. But Smerdon adds that the atmospheric and oceanic dynamics that inhibit rainfall and favour prolonged drought may be essentially random and so almost unpredictable.

Last week’s findings highlight the broader challenge of predicting how precipitation patterns will change as the global climate warms. Models are often at odds over the very direction of regional changes. For example, different projections prepared for the Colorado Water Conservation Board disagree on whether mean precipitation in the state will increase or decrease by 2050.

 Presumably, there is therefore legitimate reason to be somewhat skeptical of climate model predictions for changes in rainfall patterns in Australia due to climate change.  But then again, it may be that some climate effects in some parts of Australia are easier to model than those affecting the US.  The long term decline in rainfall in the southern corner of Western Australia is, I think I have read, consistent with climate modelling, for example.

But in any event, are these uncertainties reason to let what is essentially the biggest experiment ever devised to continue?   I mean, if some relatively small, random things determine US megadroughts, doesn't it mean that some clear non-random things (say, a 2 degree global temperature increase, and increased humidity) is likely to have a very big effect indeed?

The hilariously dim Detective Hoft

I guess people sort of expect the identification of suspects behind bombings to happen very quickly these days, and therefore we still have the news dominated by the Boston bombing and the apparent lack of success in working out who was behind it.

It's presumably not the work of a group that wants to claim responsibility, which one would think tends to make it a little less likely to be inspired by Islamist.  On the other hand, it does have the same indiscriminate terror aspect of the 2005 London bombings.

Speculation that it is the work of the extreme Right does have some things going for it:  the date, the recent wingnut hyperventilating about armed resistance over gun control laws, and the fact that it happened in a national Democrat stronghold.  On the other hand, it didn't target a government building or service, which seems a little odd.

For novelty value, I think I heard Alan Jones on Sunrise this morning speculating that it could be Left wing radicals from Harvard.  Why exactly they would want to target a marathon - surely the cleanest and Greenest of public events - remains a mystery only known to Alan.  (He's just out to try to even up the score.)

There's also the "generic, attention seeking nutter" scenario, which isn't getting all that much of a run, but didn't the last Batman film (which I didn't care to see) feature general terrorist mayhem caused by bombing public places?   Given the cinema shooting caused by a deranged Batman fan, I have to wonder if this will be another cinema inspired piece.

But the stupidest response to the event has been by dumb Right wing blogger Jim Hoft at his Gateway Pundit blog.  Amongst other dim sins, yesterday I noticed that in response to news that the police were searching someone's apartment, Hoft (for unfathomable reasons) decided it would be  a good idea to look up some address site to find a list of apparent residents in the building and link to it!  The reason he did this is pretty clear:  in a later post, he specifically says "several foreigners live in the building."   Ooh.  Scary stuff, hey?

Then, overnight, it was a bunch of photos of the young Saudi national who lived in the apartment taken from his Facebook page.   The scoundrel:  there he is, doing a silly jump at Disneyland.

But later of course:   whoops, sorry folks, he's been ruled out as a suspect by the police.  (Actually, I am making up the "sorry" bit:  there is no apology from Hoft.)

In fact, the dimwit is upset that "Left wing blogs" have "gone on the attack" about him.  Diddums, Jim?

But hey, who is the idiot who is blaming President Obama for the attack, before we have any clear idea  about who is behind it?

Hoft is the stupidest popular Right wing blogger out there, as Charles Johnson has said for years.

Build your own ice dome on the moon

Ice Dome Construction for Large Scale Habitats on Atmosphereless Bodies

Well, I suppose this could be useful if they found a lot of underground ice in the shadowed areas near the lunar poles.   Just start with a thin plastic film dome, inflate it a bit with nitrogen, and boil off the ice underneath to get it to sublimate on the film above.  Then pressurise it underneath.

Make it a meter thick, and it would even be reasonably good for cosmic ray protection. 

He's not talking tiny domes:  600 or 900 m diameter.   I wonder how chilly you might have to keep the breathable atmosphere beneath it. 

Neat, in any case.

A very Japanese app

Answering nature's call with a smartphone 

Users of Japan’s first smartphone-controlled toilet can simply touch their screens to flush, adjust bidet functions, change seat temperatures and even keep a “diary” of all those relaxing moments.

Housing equipment manufacturer Lixil Corp. said it developed the toilet after learning that an increasing number of people take their smartphones with them to the bathroom.
 .....
“It is popular among those who want to relax in their bathrooms,” said a Lixil public relations official. “It has also received positive responses thanks to its built-in speaker to play music downloaded into smartphones.”

The new toilet is remotely controlled through application software.
Users first register their favorite position of the water spray, water temperature and other settings in advance. When they enter the bathroom, their smartphones automatically relay the information to the toilet to change the settings.

That eliminates the troublesome task of manually changing the configuration set by family members and other people who share the same bathroom.

Pepsi Max may continue

Sweet news: No evidence that artificial sweetener aspartame's bad for you

I suppose I have, on average, 5 cans of Pepsi Max in a week.

The safety of aspartame is therefore of some interest.  This article is full of reassurance that it is.

However, some discussion in the comments regarding blood sugar reaction to it are of interest.  I hope this has been looked into adequately.

Arrietty appreciated

On Saturday night, the family watched the recent Studio Ghibli animation Arrietty on DVD.

I once read an interview in which Miyazaki (who didn't actually direct this, but has a writing credit, and his typical character design is very evident) said that he regrets that children today spend so much time in the "virtual" world, as it prevents them from getting out and exploring the natural world which he so lovingly illustrates in his movies.  He would rather they watched his films once, and then got outside.

That's a nice and quaint sounding sentiment, but the problem is, Miyazaki's films are so routinely  full of beautiful and detailed artwork, they are just about the most re-watchable animation ever made.

Arrietty is no exception - in fact, it seemed to me to be just about the most consistently beautiful Ghibli film I've seen.  It's impossible to illustrate this adequately here, but if you click to enlarge the following, you'll get at least an idea of the detail with which it has been made:

   

I have looked on Youtube at the trailer for American and English voiced versions, and they both seem rather wrong for the Japanese atmosphere.  The Australian DVD can be watched in Japanese with English subtitles, and that's what I would recommend.

The story ends a bit abruptly for my liking; but it's more about the trip.  Highly recommended.

Not sure that they should always be listened to...

Architects back restoration of earthquake-hit New Zealand cathedral

I see that there is a bit of fight going on as to what Christchurch should do regarding the restoration of its Anglican cathedral, which currently looks like this:
 




(My own photo of how it used to look, a year or so before the earthquake, is here.)

The proposals are basically either to rebuild it to look something like it used to, or to go with something completely different, like this:

Call me an architectural heathen if you will, but I think that looks quite nice.  Here's how it is imagined to look inside:

I still can't see a problem.  It is, according to the Cathedral's website, where you can read more about the design, " a lightweight engineered timber structure reinterprets the gothic architectural tradition."

A timber cathedral in New Zealand seems quite reasonable to me.

Follow up to Simon Crean interview

Sounds encouraging...

Emissions from power sector drop to decade-low: study

Australia's greenhouse gas emissions from electricity generation have fallen to a 10-year low as coal-fired power slumped to its lowest level in a decade, a new report says. 

At the same time, the share of renewable energy in the National Electricity Market (NEM) has soared beyond 12 per cent and looks set to continue rising.

In its latest quarterly emissions outlook, energy and carbon research firm RepuTex found coal power made up 74.8 per cent of the NEM in the three months ended in March - its lowest point in 10 years.
Coal was at more than 85 per cent of the NEM four years ago, when wind made up just half a per cent of the overall mix.

Today, wind generation is at 3.8 per cent, hydro 8.7 per cent and gas at 12.7 per cent of the NEM.
"Renewables are basically cancelling out coal," RepuTex executive director Hugh Grossman told AAP on Thursday.

But, hey, where is solar?

Things in Space

Three space related stories:

*  that video that's been around for a week or so showing the gloopy way tears would hang around an astronaut's face is worth watching:



*  that story about an experiment on board the International Space Station which might, or might not, finally solve what dark matter is about is given a pretty good treatment in New Scientist.  A key part:

Since May 2011, the Alpha Magnetic Spectrometer has been sitting on the International Space Station, sifting through billions of charged cosmic rays for evidence of those annihilations. If it sees an excessive number of positrons relative to electrons at a certain energy, that might just be a compelling sign of dark matter.

On 3 April, AMS designer Samuel Ting of the Massachusetts Institute of Technology reported an expected rise in the ratio of positrons to electrons at energies between 10 and 350 gigaelectronvolts. Frustratingly though, the upturn is not yet sharp enough to attribute to dark matter collisions since the extra positrons could still come from more mundane sources like pulsars. "It's an indication, but by no means is it a proof," Ting says.

In the meantime, a further quirk in the results suggests that if the particles are dark matter, they may not be vanilla WIMPs.

The simplest models predict there should be only a certain amount of dark matter hanging around, and that WIMPs should rarely meet. But AMS has spotted too many positrons for that – so what could make WIMPs collide in space more often than expected?

In 2008, when the PAMELA satellite found a similar excess of positrons, Neal Weiner of New York University and colleagues suggested that WIMPs are drawn together under a force of their own. This new force increases their collision rate but would have escaped our gaze until now because it ignores ordinary matter entirely.

 But perhaps the biggest surprise is:  who knew there was valuable science being done on the space station?

*   I'm sure why the story of the escaped poo during the Apollo 10 mission turned up on the internet s this week, but it is very hard not to laugh while imaging the crisis on board:

"Oh -- Who did it?" Tom Stafford asks at one point. Confused, Young and Cernan reply, "Who did what?"
Cernan: "Where did that come from?"
Stafford: "Get me a napkin quick. There's a turd floating through the air."
Young: "I didn't do it. It ain't one of mine."
Cernan: "I don't think it's one of mine."
Stafford: "Mine was a little more sticky than that. Throw that away."
Young: "God Almighty"
(laughter)

 See - an unmanned satellite has never made you laugh, has it?   

I wonder what Krugman says about this...

IMF ponders missing inflation mystery - Business - ABC News (Australian Broadcasting Corporation)

Paul Krugman loves to point out that economists aligned with the Right have been Wrong in their warnings about dangerous inflation  being just around the corner for years.  So, it's interesting to hear the IMF saying they're not sure why inflation has gone away, too.

An amusing story found while looking for something else

A former Canberra journalist, writing about an incident in Canberra in the 1960's:

One of the more spectacular drunken performances of the 1960s was in the Senate chamber, when Labor Senator from Western Australia Harry Cant found himself seriously drunk and trapped by a division. The doors were locked and the division required Labor senators to cross to the other side of the chamber, sitting in the places of the government senators for the count, while the government senator moved to the opposition benches. Cant was overcome by an urgent need to vomit. Looking around desperately, he came to a decision. Opening the desk drawer of the government senator’s desk where he was seated, he was violently and noisily sick into it.

When the division was over and the senators resumed their normal places, the government senator in whose place Harry had sat was understandably disgusted. The stench created by this extraordinary happening filled the chamber. He did not draw the President of the Senate’s attention to the outrage or make a fuss. Urgent action was required. All this had taken place in the full view of the journalists in the Senate press gallery and those in the public gallery. News of the outrage was soon all over Parliament House and journalists rushed to get the story. Medical practitioner Dr Felix Dittmer, a Queensland Labor Senator, had the answer. He denied Cant was drunk and ordered that an ambulance be urgently called to take Cant to the Royal Canberra Hospital, just across Commonwealth Avenue Bridge in Acton. Dittmer stated that Cant was suffering from an acute case of ‘renal colic’.

The ambulance arrived and a Labor colleague suggested to Dittmer that it would be discreet for Harry, now prone on a stretcher, to be taken through the back exit of Parliament via the kitchen. Labor Deputy Senate Leader, Pat Kennelly, rejected this. So the little procession of the two ambulance officers carrying the stretcher with Cant prone, and Dittmer leading, made its way through the Senate opposition lobby, across King’s Hall where visitors gaped, and down the front steps to the waiting ambulance. In hospital, Cant made a speedy recovery and was discharged the next day. From then on, if an MP entered either the house or the Senate looking a little confused, the interjection would go out: ‘Renal colic.’

More reason to believe the importance of heat in oceans

New Study: When You Account For The Oceans, Global Warming Continues Apace | ThinkProgress

The abstract of the paper itself:

 Despite a sustained production of anthropogenic greenhouse gases, the Earth’s mean near-surface temperature paused its rise during the 2000–2010 period¹. To explain such a pause, an increase in ocean heat uptake below the superficial ocean layer^{2, 3} has been proposed to overcompensate for the Earth’s heat storage. Contributions have also been suggested from the deep prolonged solar minimum⁴, the stratospheric water vapour⁵, the stratospheric⁶ and tropospheric aerosols⁷. However, a robust attribution of this warming slowdown has not been achievable up to now. Here we show successful retrospective predictions of this warming slowdown up to 5 years ahead, the analysis of which allows us to attribute the onset of this slowdown to an increase in ocean heat uptake. Sensitivity experiments accounting only for the external radiative forcings do not reproduce the slowdown. The top-of-atmosphere net energy input remained in the [0.5–1] W m⁻² interval during the past decade, which is successfully captured by our predictions. Most of this excess energy was absorbed in the top 700 m of the ocean at the onset of the warming pause, 65% of it in the tropical Pacific and Atlantic oceans. Our results hence point at the key role of the ocean heat uptake in the recent warming slowdown. The ability to predict retrospectively this slowdown not only strengthens our confidence in the robustness of our climate models, but also enhances the socio-economic relevance of operational decadal climate predictions.

The important  conclusion:  a "pause" in average surface temperatures does not mean the planet is not warming.

Laser weapons, yay...

Navy deploys laser weapon to shoot down drones. (video)

The video's not that exciting, but it was interesting to read this: 

On Monday, the Navy announced that it plans to deploy its first shipboard laser in the Persian Gulf next year, for use against Iranian attack speedboats and drones. The laser isn't powerful enough to shoot down a missile, but as the video below shows, it can burn right through a small unmanned aircraft.

Less-powerful settings give it the option to "dazzle" a drone's sensors without taking it down.

The laser system is still in development, but so far it has successfully destroyed all 12 of the small boats and drones that the Navy has tested it on, the Wall Street Journal reports.

The system is far from perfect. It doesn't work in bad weather, and it fires only in a straight line, so it can't aim around obstacles, limiting its usefulness on land.

The upside is that it's cheap and easy to use. A nonpartisan study for Congress puts the cost of a sustained pulse at less than a dollar, compared to some $1.4 million for a short-range interceptor missile.

 I didn't think they would be so cheap to run...

That odd 1960's event re-visited

UFO returns to park

I had a post in 2010 about this peculiar UFO incident in Melbourne in 1966.  (Something odd was definitely seen, and it seems the military knew about it, but what it was remains very obscure.)

Nice to see that they local area is to get a UFO playground to commemorate it!

More than you probably needed to know

Passing gas: A modern scientific history - Salon.com

This is a really long extract about flatulence, and other related intestinal facts.  There is quite a bit to be amused by, such as this about early research into smells:

I ask Levitt whether it was difficult to recruit volunteers for the flatus studies. It wasn’t, partly because the subjects were paid for their contributions. People who sell their flatus are more or less the same crowd who turn up to sell their blood.

“What was hard,” Levitt says, “was finding the judges.” Levitt needed a pair of odor judges to take “several sniffs” and rate the noxiousness — from “no odor” to “very offensive” — of each of the sixteen people’s flatal contributions. The hypothesis was that noxiousness would correlate with the combined concentrations of the three sulfur gases. And it did.

Curious as to which olfactory notes the different sulfur gases contributed to the overall bouquet of flatus, Levitt purchased samples of the three gases from a chemical supply house. The judges agreed on the following descriptors: “rotten eggs” for hydrogen sulfide, the gas with the strongest correlation to stink; “decomposing vegetables” for methanethiol; and “sweet” for dimethyl sulfide. Though lesser players like methylmercaptan contribute as well, it is for the most part these three notes, in subtly shifting combinations and percentages, that create the infinite olfactory variety of human flatus. To quote Alan Kligerman, “A gas smell is as characteristic of a person as a fingerprint is.” But harder to dust for.

But I did learn things I didn't know:  there is a tablet that is available that is very effective at removing the smell - Devrom.  But even in America - home of the TV advertisement for douching, for goodness sake - no one likes to see or hear advertisements for curing smelly farts.   Hard to believe:

Bismuth pills, on the other hand — and Levitt has tested these, too — reduce 100 percent of sulfur gas odor. Bismuth is the “bism” in Pepto-Bismol. Daily doses of Pepto-Bismol can irritate the gut, but not bismuth subgallate, the active ingredient in Devrom “internal deodorant” pills.

I had never before heard of Devrom. This may be because mainstream magazines often refuse to run the company’s ads. Devrom’s president, Jason Mihalopoulos, e-mailed me a full-page ad he had hoped to run in Reader’s Digest and AARP magazine. A smiling gray-haired couple stand arm in arm below the boldface headline “Smelly Flatulence? Not since we started using Devrom!” Mihalopoulos was told he could not use the phrases “smelly flatulence” and “stinky odor,” or the word “stool.” One of the magazines suggested changing the copy to say that the product “eliminates intestinal gas,” but that’s not what Devrom does. That’s what Beano does. So unless you read the Journal of Wound Ostomy & Continence Nursing or the International Journal of Obesity Surgery, you won’t see the happy, internally deodorized Devrom couple.

 And as for the hydrogen sulfide component, we get this useful bit of information, showing that the worst flatulence won't kill you:

The concentration of hydrogen sulfide in offensive human flatus is around 1 to 3 parts per million. Harmless. Ramp it up to 1,000 parts per million — as can exist in manure pits and sewage tanks — and a few breaths can cause respiratory paralysis and suffocation. Workers die this way often enough that a pair of physicians, writing in a medical journal, coined a name for it: dung lung. Hydrogen sulfide is so swiftly lethal that farm- and workplace-safety organizations urge anyone who enters a manure pit or attempts to clear a blocked sewage pipe to wear a self-contained breathing apparatus. ...

It is fitting that the Devil is said to smell of sulfur. Hydrogen sulfide is a diabolical killer. Its telltale rotten-egg smell, screamingly obvious at 10 parts per million, disappears at concentrations above 150 parts per million; the olfactory nerves become paralyzed.

 What a sneaky gas...

Personal hygiene from far away

I've just noticed that the new deodorant I bought on the weekend (novel because it contains silver ions, which readers will recall work for Japanese space underwear, and therefore hopefully will also work under my armpits) is made in Thailand.   (Mind you, it still contains aluminium, so perhaps the amount of silver ions is inconsequential.  How would you know?)

The toothpaste I am about to start using is from Germany.   So are my preferred toothbrushes.  (Guess which supermarket chain sell them.)   I have noticed razors that come from Greece and France.  I think I tried Korean ones from Aldi once, and they were terrible.   

A lot of soaps and detergents seem to come from New Zealand now.

I am worried that with such globalisation, come the collapse of civilisation, personal hygiene will be one of the first crises.  

Anyhow, the successful meal of the weekend was a beef and beer casserole, based on this recipe.  Next time I would add perhaps half of the sugar, and twice as much Worcestershire sauce.   (I also added a diced carrot and stick of celery too.)  The dumplings came out nice.  I had been wanting to try cooking with beer in a casserole instead of wine for some time.  Can scratch that off the list now.

Black holes and firewalls

Astrophysics: Fire in the hole! : Nature News

Here's a lengthy and interesting article about some relatively new ideas and problems with the physics of black holes.

It's pretty remarkable that working out the physics on the boundary of a black hole is still the subject of such controversy, so many decades after physicists started to think about it.  Still, I guess it's not as if they have one nearby to actually toy with.  In fact, now that I think about it, how close is the nearest likely black hole to Earth?  Seems it might be 1,500 light years - not so far if you're considering the galaxy as a whole.  From a 2012 article:

This beautiful photo from the Hubble Legacy Archive offers a striking look at the Trapezium, four closely packed stars found inside the Orion nebula, some 1,500 light-years away. Lurking inside that image might be our nearest black hole neighbor.

The question of which black hole is the closest to Earth is surprisingly tricky to answer. V4641 Sgr might be just 1,600 light-years away, or it might equally possibly be more like 24,000 light-years away. We've got a better sense of the location of V404 Cygni, which is just 7,800 light-years away. Considering we're a little under 30,000 light-years from the supermassive black hole at the center of the Milky Way, those black holes are certainly in the cosmic vicinity, but they're not exactly super close.

That's why the Trapezium is so intriguing. Something about the stars' movements just isn't right, and the most likely explanation is a hidden black hole.

 Anyway, back to the Nature article.  It's mainly about the idea that the boundary of a black hole might, or might not, have a particularly dangerous aspect to it:

Hawking had shown that the quantum state of any one particle escaping from the black hole is random, so the particle cannot be carrying any useful information. But in the mid-1990s, Susskind and others realized that information could be encoded in the quantum state of the radiation as a whole if the particles could somehow have their states ‘entangled’ — intertwined in such a way that measurements carried out on one will immediately influence its partner, no matter how far apart they are.

But how could that be, wondered the Polchinski’s team? For a particle to be emitted at all, it has to be entangled with the twin that is sacrificed to the black hole. And if Susskind and others were right, it also had to be entangled with all the Hawking radiation emitted before it. Yet a rigorous result of quantum mechanics dubbed ‘the monogamy of entanglement’ says that one quantum system cannot be fully entangled with two independent systems at once.

To escape this paradox, Polchinski and his co-workers realized, one of the entanglement relationships had to be severed. Reluctant to abandon the one required to encode information in the Hawking radiation, they decided to snip the link binding an escaping Hawking particle to its infalling twin. But there was a cost. “It’s a violent process, like breaking the bonds of a molecule, and it releases energy,” says Polchinski. The energy generated by severing lots of twins would be enormous. “The event horizon would literally be a ring of fire that burns anyone falling through,” he says. And that, in turn, violates the equivalence principle and its assertion that free-fall should feel the same as floating in empty space — impossible when the former ends in incineration. So they posted a paper on the preprint server, arXiv, presenting physicists with a stark choice: either accept that firewalls exist and that general relativity breaks down, or accept that information is lost in black holes and quantum mechanics is wrong¹. “For us, firewalls seem like the least crazy option, given that choice,” says Marolf.

 There's lots more, and it is well worth reading.

As seen at the IPA dinner