New Support for Nuclear Winter

[Trakar]

Thanks to Ari Jokimaki's site, I ran across this recently published study:

The role of atmospheric nuclear explosions on the stagnation of global warming in the mid 20th century - http://www.citeulike.org/article/8682491

Abstract -

This study suggests that the cause of the stagnation in global warming in the mid 20th century was the atmospheric nuclear explosions detonated between 1945 and 1980. The estimated GST drop due to fine dust from the actual atmospheric nuclear explosions based on the published simulation results by other researchers (a single column model and Atmosphere-Ocean General Circulation Model) has served to explain the stagnation in global warming. Atmospheric nuclear explosions can be regarded as full-scale in situ tests for nuclear winter. The non-negligible amount of GST drop from the actual atmospheric explosions suggests that nuclear winter is not just a theory but has actually occurred, albeit on a small scale. The accuracy of the simulations of GST by IPCC would also be improved significantly by introducing the influence of fine dust from the actual atmospheric nuclear explosions into their climate models; thus, global warming behavior could be more accurately predicted.

I realize that many of the involved scientists and advocates were convinced, or deferred to what were considered compelling arguments that the effects of "nuclear winter" had largely been exagerated especially in the popularized accountings of such, and by some of its high profile "celebrity scientists" (particularly Sagan). But there is a big difference between questions of impact degree in those days of rudimentary atmospheric understandings and modellings, and the complete dismissal and discrediture of the concept, that are occassionally implied in discussions of "things that science got wrong."

I'm sure there are political arguments on both sides, but what this research brought to mind, is the question of what the actual science said, and what other (contra)supporting modern evidences and studies might have gone unnoticed into the journal archives,...I'm thinking many modern dust, ash and aerosol modelling studies (rather like this specific paper).

The Wiki accounting is pretty much as I recall and understand the Nuclear Winter concept.

If any one feels that this is a distorted or overly biased account, please provide what you consider more appropriately accurate accounts for comparison.

 

[soylent]

I realize that many of the involved scientists and advocates were convinced, or deferred to what were considered compelling arguments that the effects of "nuclear winter" had largely been exagerated especially in the popularized accountings of such, and by some of its high profile "celebrity scientists" (particularly Sagan).

That the effects of nuclear winter have been very much exaggerated are abundantly clear. Most of these studies, when you actually look at them, use Hiroshima as a source for figuring out the extent of fire storms.

But the majority of the fires in Hiroshima and Nagasaki were not caused by heat flash; they were caused by the blast, which toppled char-coal braziers used for cooking breakfast.

Hiroshima had gone 27 days without rain and its buildings where made mostly of wood and paper.

Curiously Nagasaki is almost never used as a source and it never had a firestorm; despite being mostly made out of wood and paper and despite using char-coal cooking braziers and having gone 10 days since last rain. It takes rather carefully contrived conditions to get a fire storm.

Isolated fires, like the kuwait oil fires or a forest fire, are not able to loft particles high enough to have a global effect. So the extent of fire storms makes a very big difference in the magnitude of the resulting 'nuclear winter'.

 

[Trakar]

That the effects of nuclear winter have been very much exaggerated are abundantly clear. Most of these studies, when you actually look at them, use Hiroshima as a source for figuring out the extent of fire storms.

But the majority of the fires in Hiroshima and Nagasaki were not caused by heat flash; they were caused by the blast, which toppled char-coal braziers used for cooking breakfast.

Hiroshima had gone 27 days without rain and its buildings where made mostly of wood and paper.

Curiously Nagasaki is almost never used as a source and it never had a firestorm; despite being mostly made out of wood and paper and despite using char-coal cooking braziers and having gone 10 days since last rain. It takes rather carefully contrived conditions to get a fire storm.

Isolated fires, like the kuwait oil fires or a forest fire, are not able to loft particles high enough to have a global effect. So the extent of fire storms makes a very big difference in the magnitude of the resulting 'nuclear winter'.

In the initial nuclear winter studies the issue wasn't the cause of the ash, merely the production of ash and dust and the lifting of it into the upper atmosphere. You seem to be presenting an argument that doesn't correspond to the Wiki link I posted in the OP, do you have any sources or references to support your contentions?

I am interested in learning more about the opinions you express as they seem quite common but don't seem to be in accord with what the actual science expresses in regards to the phenomenon of nuclear winter and I am curious to learn the basis and support of what seems to be a virtual concensus among U S lay "man on the street" types who have any understanding of, or opinion on, the phenomenon at all.

Here are a few of the more modern studies I am aware of but they all tend to support the science understandings I am familiar with, and I am most interested in the sources of "very much exaggerated," and "Isolated fires, like the kuwait oil fires or a forest fire, are not able to loft particles high enough to have a global effect."

Nuclear winter revisited with a modern climate model and current
nuclear arsenals: Still catastrophic consequences - http://www.dorringtoninstruments.com/columbia/Robock_nuclear_winter.pdf

Atmospheric effects and societal consequences of regional scale
nuclear conflicts and acts of individual nuclear terrorism - http://envsci.rutgers.edu/~gera/nwinter/ToonAcp-7-1973-2007.pdf

Climatic consequences of regional nuclear conflicts - http://envsci.rutgers.edu/~gera/nwinter/RobockAcp-7-2003-2007.pdf

and of course the OP paper which seems to disagree with your statement concerning the Kuwaiti oil fires and forest fires.

The role of atmospheric nuclear explosions on the stagnation of global warming in the mid 20th century - http://www.citeulike.org/article/8682491
(that paper may not be easily accessible but the author published a similar piece in 2010 that uses some of the same arguments and data -
Influence of Atmospheric Nuclear Explosions on Climate Change - http://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/42589/1/fujii.pdf)

But I really don't want to get into any general climate or AGW discussions here, I'm more interested in staying focussed on Nuclear weapons induced effects and why there is an apparent discrepancy between general perceptions and the actual science.

 

[mike3]

I'm curious: does this have any bearing on studies of things like asteroid impacts as well? If this seemingly tiny amount of dust could do all that, what could the vastly greater amount of dust released by a good-sized asteroid strike do?

 

[theprestige]

I'm curious what they mean by "nuclear winter". Growing up, it was my understanding that the term referred to a climate change brought about by particulates in the air--fallout from the world's nuclear arsenals being launched in anger.

In that sense, radiation effects aside, hasn't "nuclear winter", been tested on a small scale several times in the last hundred years or so, in the form of major volcanic eruptions?

It seems to me, based on the abstract, that either these researchers are using the term "nuclear winter" to refer to something else entirely, or they are contributing a molehill to the mountain of data we already have on the subject.

 

[Mark6]

I'm curious what they mean by "nuclear winter". Growing up, it was my understanding that the term referred to a climate change brought about by particulates in the air--fallout from the world's nuclear arsenals being launched in anger.

Yes

In that sense, radiation effects aside, hasn't "nuclear winter", been tested on a small scale several times in the last hundred years or so, in the form of major volcanic eruptions?

Yes. Year Without Summer -- Tambora eruption.

 

[Trakar]

I'm curious: does this have any bearing on studies of things like asteroid impacts as well? If this seemingly tiny amount of dust could do all that, what could the vastly greater amount of dust released by a good-sized asteroid strike do?

I would certainly assume that there are crossover applications. I believe that the science supports such understandings. If I'm not mistaken the nuclear winter issues were originally derived from impact studies, but I may have that confused.

 

[Trakar]

I'm curious what they mean by "nuclear winter". Growing up, it was my understanding that the term referred to a climate change brought about by particulates in the air--fallout from the world's nuclear arsenals being launched in anger.

In that sense, radiation effects aside, hasn't "nuclear winter", been tested on a small scale several times in the last hundred years or so, in the form of major volcanic eruptions?

It seems to me, based on the abstract, that either these researchers are using the term "nuclear winter" to refer to something else entirely, or they are contributing a molehill to the mountain of data we already have on the subject.

I don't know that I would state the issue in quite that manner, but yes, to my understandings, the issue is well respected and established science that has been added to significantly over the last handful of decades. I have just noticed with increasing frequency over the last decade that "nuclear winter" is often categorized as flawed or disproven/discredited science. I am trying to discover if there have been contra-value studies or researches that I am unaware of which have contributed to that perspective, or if it is a stance that has little or nothing to do with the science involved.

 

[Travis]

I wasn't aware people thought a nuclear winter was complete hogwash. It was presented as much scarier than it might actually be (much like radioactive fallout) but that a full nuclear exchange would effect the climate just seems logical.

 

[theprestige]

I don't know that I would state the issue in quite that manner, but yes, to my understandings, the issue is well respected and established science that has been added to significantly over the last handful of decades. I have just noticed with increasing frequency over the last decade that "nuclear winter" is often categorized as flawed or disproven/discredited science. I am trying to discover if there have been contra-value studies or researches that I am unaware of which have contributed to that perspective, or if it is a stance that has little or nothing to do with the science involved.

I think the idea is that the original concept of "nuclear winter" as an apocalyptic climate change brought about by nuclear war had little or nothing to do with the science involved.

Over the years, as science has gotten involved, it has emerged that the nuclear winter predicted by the peaceniks of the previous generation was exaggerated and unrealistic. And that's pretty much where we are today.

I still don't know what this has to with the abstract quoted in the OP, which seems to have nothing to do with particulate fallout caused by numerous ground bursts (the traditional cause of "nuclear winter"), but rather with brief bursts of radiation and attendant shock waves in the upper atmospher (not the traditional cause of "nuclear winter").

So what do the abstract's authors mean by "nuclear winter", anyway? If they're interested in the traditional definition, it seems to me that they'd be better off studying volcanic eruptions. If they're interested in something else, it seems to me they should probably not use the term "nuclear winter".

Even if upper-atmosphere nuclear detonations could have a substantial effect on global climate change, the scenario that gave us the term--a nuclear war between the US and the USSR--would have involved large numbers of ground- or air-burst nukes, and very few upper-atmosphere detonations. Remember: the nuclear arsenals of the 20th century were intended primarily to flatten cities and shatter launch platforms. Maybe a few upper-atmosphere comm jammers.

So I still don't understand the authors' choice of terminology. They're using the term nuclear winter in a context that makes no sense to me at all, and seems to indicate a profound ignorance of the usual context of the term.

 

[Trakar]

I wasn't aware people thought a nuclear winter was complete hogwash. It was presented as much scarier than it might actually be (much like radioactive fallout) but that a full nuclear exchange would effect the climate just seems logical.

And this may well be the issue. It's rather like people trying to characterize climate change according to the movie "The Day after Tomorrow." Unfortunately, with nuclear winter, there seem to those whose only connection to the term are the exaggerations. But this perspective isn't limited to a general population without any direct connection to the science or the times when is was a more topical issue. There seems to be an active agenda among some to confuse and conflate the issue deliberately.
I've found a few references to support this contention:

"The rise of the extreme killers" in the Sunday Times back on April 19, 2009
where nuclear winter is categorized as one of the historic false alarms of science along with "in the shadow of the Bomb" (referring to cold war fears of nuclear war), and the "coming Ice age." Portraying these as examples of where the science was wrong and alarmist scientists promoted flawed science to scare the general population. The National Post ran a similar piece back in April of 2000.

As stated earlier, I've just started noticing many people casually referring to nuclear winter as though it were discredited science and foolish alarmism, and after running across these most recently published papers, started wondering maybe there was a more legitimate scientific refutation afoot that I had somehow missed (I was in the military and overseas throughout most of the '80s and not real focussed on the science so much as the practical daily threat the former Soviet Union represented). I was aware that there had been some media exaggerbation (but that's kinda what they do) and it had led to some rather prominent spokesmen (Sagan, Asimov, etc.,) had to publically backtrack a bit from some of their more dramatic earlier discussion points.

I just find it curious that the entire concept of nuclear winter is now often portrayed as an example of where science got it wrong.

 

[Trakar]

I think the idea is that the original concept of "nuclear winter" as an apocalyptic climate change brought about by nuclear war had little or nothing to do with the science involved.

This isn't really my understanding of the science either, though I'd love any reference you can supply for that position!

Over the years, as science has gotten involved, it has emerged that the nuclear winter predicted by the peaceniks of the previous generation was exaggerated and unrealistic. And that's pretty much where we are today.

My understanding is that the science sparked the media, and the media cranked up the activists. Likewise, the controversial issue began when Sagan and a few other researchers proposed the idea that as little as 100MT exchange could trigger extreme climate responses of decades in length. This was rather routinely dealt with (by Teller, IIRC).

I still don't know what this has to with the abstract quoted in the OP, which seems to have nothing to do with particulate fallout caused by numerous ground bursts (the traditional cause of "nuclear winter"), but rather with brief bursts of radiation and attendant shock waves in the upper atmospher (not the traditional cause of "nuclear winter").

To my understanding, "nuclear winter" wasn't a direct effect of weapons detonation, but rather the product of urban firestorms generating ash and aerosol plumes that extended into the stratosphere. Sorry don't have a non-paywall source for the OP paper at this time, but it primarily looks at open air testing which threw various composition plumes into the stratosphere as a more direct result of the actual nuclear test blasts. This is actually a more significant effect than what was actually proposed and calculated in the initial nuclear winter proposals. The author actually seems to think that a significant portion of the cooler climate trending in the late 50s through the early 70s was due to the aerosols created and transported into the stratosphere by open-air nuclear tests. I've nothing against discussing the author's theory and where we might feel it to be weak, or strong, but I was really merely using it as the example of what made me think about the fact that this was still an active and vital area of scientific research and understanding, and yet many seem to be using the idea of "nuclear winter" as an example of bad or invalid science.

 

[CapelDodger]

As I recall, the idea of Nuclear Winter was connected to a general exchange (equivalent to lots of explosive volcanoes going off at once), and the commonly-held assumption that we'd all be screwed anyway if that happened. It wasn't so much about a new Ice Age (although some did predict that, without enough climate knowledge IMO) but that even a few years "without summers" would further devastate any survivors.

Fortunately we never ran the experiment. Nuclear Winter wasn't really a controversial issue during the MAD old days, but suddenly became one when fighting (and winning) a (limited) nuclear war came back on the stage, in Reagan's days. Not surprisingly it tended to be right-wingers who regarded the science as settled against a nuclear winter.

This paper is very interesting, but there's still the 40's to explain. Other aerosols seem a likely explanation, but the science is far from settled on that. It's a shame we didn't have satellite coverage in those days.

 

[bokonon]

Well hell, if that's the case, then the solution to global warming could be as simple as letting every jet release a shoebox full of fireplace ashes when it reaches cruising altitude. Done.

 

[nota]

jets allready cause global dimming from particles in their exhaust
no need to add to it

 

[Dinwar]

Well hell, if that's the case, then the solution to global warming could be as simple as letting every jet release a shoebox full of fireplace ashes when it reaches cruising altitude. Done.

Yeah....Thus reducing primary production, and causing even greater ecological devistation (it wasn't the impact that killed the dinosaurs, but the the fact that the dust essentially shut down primary production for a long, long time). This would be a Very Bad Thing (tm).

To my understanding, "nuclear winter" wasn't a direct effect of weapons detonation, but rather the product of urban firestorms generating ash and aerosol plumes that extended into the stratosphere.

This is my issue with the nuclear winter thing--this value would be horribly difficult to calculate. I mean, a bomb dropped on a city in an island nation would be one thing. A bomb dropped in, say, an air force base in wildfire country during a drought would be another all together. I'm not saying it's impossible, just that in order to crunch the numbers back in the Cold War they'd have to have simplified these sorts of things to the point where they're more cartoon than not.

It's not like ash has never been thrown into the atmosphere before, though. I wonder how bolide impacts affected the environment in the past. Obviously Chixilub had devistating consequences, but that was an order of magnitude larger than anything humans are capable of (at least) and at one location--a shower of asteroids, Levee-Shoemaker 9 style, could do a lot more damage with a lot less mass (there's no evidence for it, but it's a possibility). And the real threat with nuclear winter isn't a mass extinction, but a HUMAN extinction, meaning the extinction of a cosmopolitane, omniverous, large species. Could be something worth looking into.

 

[CapelDodger]

This is my issue with the nuclear winter thing--this value would be horribly difficult to calculate. I mean, a bomb dropped on a city in an island nation would be one thing. A bomb dropped in, say, an air force base in wildfire country during a drought would be another all together. I'm not saying it's impossible, just that in order to crunch the numbers back in the Cold War they'd have to have simplified these sorts of things to the point where they're more cartoon than not.

I'm sure it was very much a back-of-an-envelope calculation, predicated on a general exchange across the North Pole mutually destroying Europe and North America. That would have involved thousands of warheads and all major conurbations, so perhaps the error bars could be very wide without seriously affecting the outcome. Which was pretty academic anyway, from the point of view of advanced life-forms as we know (and are) them today .

Exactly what forced the climate from the 40's through 70's is an open question of great interest and, obviously, active study. It was, to some extent, an experiment on the climate so there should be a lot to learn from it. Unfortunately the parameters were not well-constrained, but then it wasn't a designed experiment. It just happened.

 

[Trakar]

I'm sure it was very much a back-of-an-envelope calculation, predicated on a general exchange across the North Pole mutually destroying Europe and North America. That would have involved thousands of warheads and all major conurbations, so perhaps the error bars could be very wide without seriously affecting the outcome. Which was pretty academic anyway, from the point of view of advanced life-forms as we know (and are) them today .

Exactly what forced the climate from the 40's through 70's is an open question of great interest and, obviously, active study. It was, to some extent, an experiment on the climate so there should be a lot to learn from it. Unfortunately the parameters were not well-constrained, but then it wasn't a designed experiment. It just happened.

I guess it might be of some benefit to reference the early papers on Nuclear Winter so that there is some background to the considerations. Unfortunately, I don't have a good link to the first paper ("The atmosphere after a nuclear war: Twilight at noon"-Crutzen, P.J., and J.W. Birks (1982)) But here are some of the early studies contemporaneous to that premier paper.

"Climate and Smoke: An Appraisal of Nuclear Winter" - http://www.atmos.washington.edu/~ackerman/Articles/Turco_Nuclear_Winter_90.pdf

The latest understanding of nuclear winter is reviewed.
Considerable progress has been made in quantifying the
production and injection of soot by large-scale fires, the
regional and global atmospheric dispersion of the soot,
and the resulting physical, environmental, and climatic
perturbations. New information has been obtained from
laboratory studies, field experiments, and numerical modeling
on a variety ofscales (plume, mesoscale, and global).
For the most likely soot injections from a fill-scale
nuclear exchange, three-dimensional climate simulations
yield midsummer land temperature decreases that average
100 to 20°C in northern mid-latitudes, with local cooling
as large as 35°C, and subfreezing summer temperatures in
some regions. Anomalous atmospheric circulations
caused by solar heating of soot is found to stabilize the
upper atmosphere against overturning, thus increasing
the soot lifetime, and to accelerate interhemispheric transport,
leading to persistent effects in the Southern Hemisphere.
Serious new environmental problems associated
with soot injection have been identified, including disruption
ofmonsoon precipitation and severe depletion of the
stratospheric ozone layer in the Northern Hemisphere.
The basic physics of nuclear winter has been reaffirmed
through several authoritative international technical assessments
and numerous individual scientific investigations.
Remaining areas of uncertainty and research priorities
are discussed in view of the latest findings.

(full text at above link)

The NRC study
"The Effects on the Atmosphere of a Major Nuclear Exchange" (1985)
Commission on Physical Sciences, Mathematics, and Applications (CPSMA)
http://www.nap.edu/openbook.php?record_id=540&page=R1

This 1986 book ("The Medical implications of nuclear war") contains many of the important research papers and chapters detailing the state of science science at the time - alas it is a Google book so it is not complete.
http://books.google.com/books?id=NU...&resnum=1&ved=0CCcQ6AEwAA#v=onepage&q&f=false

I don't have the full paper on this one but it does posit a counterpoint argument and is by a "trail - blazing" author some of us might recognize!

"Re-analysis of the nuclear winter phenomenon" - http://www.springerlink.com/content/h37181882858v92q/

That should be enough for a start, I'm not looking to hand out a comprehensive listing, just a sampling of some of the early papers and writings so that issues of how the calculations were performed and concepts tested can be examined and the original conditions, circumstances and findings can be examined.

 

[Trakar]

"Climate and Smoke: An Appraisal of Nuclear Winter" - http://www.atmos.washington.edu/~ackerman/Articles/Turco_Nuclear_Winter_90.pdf

I just noticed that the C&P from the PDF photocopy at the above link doesn't do justice to the text which should read "...10ºC to 20ºC in northern mid-latitudes..." sorry about that!

 

[Trakar]

I have run across an interesting paper that somewhat addresses, but mostly just accurately sets the stage of the public and professional debate over nuclear winter, written in 1988 and published in Science and Public Policy, Vol. 15, No. 5, October 1988, pp. 321-334.

Nuclear winter: science and politics
http://www.uow.edu.au/~bmartin/pubs/88spp.html

It discusses both the politics in the science and the science in the politics. A very interesting read and applicable to many more modern intersections of science and politics, but I'm not sure that it gets us any closer to whether or not there are legitimate scientific questions or doubts remaining about the validity and accuracy of nuclear winter considerations.