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State of Nuclear Winter Theory?

  1. Apr 23, 2017 #1
    There seems to be a lot of conflicting research on nuclear winter theory, especially since the 1990s. Carl Sagan famously predicted that the Kuwaiti oil well fires from Operation Desert Storm would result in a small global winter, but the effects turned out to be more localized and less severe than estimated. The aftermath of the Desert Storm fires caused nuclear winter theorists to admit flaws with the models and revise their estimates, especially since it was thought that petroleum fields and related facilities would be a major contributor to the cooling effect. However, even in the revision the theorists went from talking about temperature reductions of 15 to 25 degrees centigrade (27 to 45 degrees Fahrenheit) to temperature reductions of 10 to 20 degrees centigrade (18 to 36 degrees Fahrenheit), which still seems like a major reduction (source).

    More recently some research has indicated that even a small scale nuclear water would cause more widespread cooling and possibly major ozone layer damage (summaries here).

    The earlier research seems to make it look like nuclear winter would be more of a significant short term weather change lasting a few weeks or months, while more recent research seems to point towards it producing smaller but longer lasting climatic changes.

    Also, it seems that the total volume of materials burned wouldn't be very large when compared to what occurs during an average year. For example, the estimates of total material burned here range from 1,475 to 5,075 terragrams of material (equivalent to 1.475 to 5.075 billion metric tons), but the annual world consumption of coal is already on par with even the high end estimate. What would make the combustion of that material worse than typical fossil fuel consumption?
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  3. Apr 24, 2017 #2

    jim mcnamara

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    Please do not try to post personal feelings or 'what if' extrapolations. This thread is fine with new posts citing relevant papers.

    This is not my field. What I do understand is that this is a version of pragmatic climate modeling - trying to predict consequences of a catastophic event on climate.

    In general the focus is on changes in Earth's albedo. Sulfur from large volcanic eruptions will alter insolation making tempertures on the surface temporarily lower, for example. The major difference is, I assume, duration. How long will ejecta exist in the atmosphere? Volcanic eruptions can persist for years, full blown nuclear warfare is not likely to last that long.

    The Wikipedia article seems to be a reasonable review. One needs to avoid of the noise caused by translating (dumbing down, sensationalizing) scientific research into news articles. How many causes/cures of diseases have come and gone in the news?

    What I see in the article indicates:
    1. large decline in nuclear stockpile - warheads over time
    2. the sample of papers is heavily skewed to the 1980-2008 timeframe - this is often indicative of a sea change in thinking on the subject.
    3. our understanding of climate has changed markedly from the 1980's

    My conclusion is there is less motivation for the subject as it was pursued back then. I do not know why that may be.
  4. Apr 30, 2017 #3
  5. May 2, 2017 #4
    It's impossible to post in this thread "scientific" facts or papers on the subject when the entire "Nuclear Winter" theory is floated by one book that was turned into a Hollywood movie in the 1980s.

    So in short, the theory bunks itself.

    Just reading the US and Russian declassified policy positions on Nuclear Posture reveals that the governments treat Nuclear War much differently than "MAD" suggests.

    Those can be searched on Google.


    Some more obscure papers on what the Russians do to protect themselves in a Nuclear strike is: https://www.nrc.gov/docs/ML0607/ML060760210.pdf

    It's rather complex and it's because no one takes seriously the "Nuclear Winter" theory. Except maybe movies like Terminator.
  6. May 2, 2017 #5
  7. May 2, 2017 #6


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    Is it? Do you have a source for that claim?
    They were done spread out over decades, and not over cities or other relevant flammable material. Many of them were done underground or over oceans. I don't say detonating many nuclear weapons over cities would have to lead to a strong effect, but the existing explosions did nothing to test this hypothesis.
  8. May 2, 2017 #7
    I think if really came down to global nuclear conflict I would go to the local psychiatric unit to get that checked out in case I was just being paranoid
  9. May 3, 2017 #8
    This is the VERY FIRST mention of "Nuclear Winter" (not by name but as we know it now).

    It is THIS paper written by two non-experts that tries to argue that massive fires and dirt being flung into the stratosphere will darken the sun and ruin the entire planet. You won't find any such argument before this. Everything else deals with Ozone holes and atmospheric problems relating to the structure of the atmosphere itself, all of which was debunked by actual Atmospheric tests.


    The reason the hypothesis is flimsy is the argument is flimsy. We can calculate how much dirt was pushed into the stratosphere by volcanic eruptions and that massively out weighs the calculated debris rising into the upper atmosphere from fire-bombings that we did during WW2, so why would Nuclear Weapons be any different?

    The above ground tests were important for telling us just how much material can make it into the upper atmopshere from a detonation above ground.

    Most detonations would be like "bunker busters" and so would be a mix of below/above ground.

    The paper gets more ridiculous arguing that cities in Africa and South America will also be Nuked in order to increase the number of burnable materials.


    Most Nuclear targets are as remote as were crater flats testing grounds or bikini atolls and are the ICBM silos.

    That's where will get hit the most.

    Counter cost is the scorched earth anti-city strategy and is low on the totem pole of priority. Most posturing is counter value, to hit other nuclear assets.

    Most nuclear assets aren't parked in cities.
    Last edited: May 3, 2017
  10. May 3, 2017 #9


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  11. May 3, 2017 #10
    Counter example:

    "Significant hemispherical attenuation of the solar radiation flux and subfreezing land temperatures may be caused by fine dust raised in high-yield nuclear surface bursts and by smoke from city and forest fires ignited by airbursts of all yields." [Turco et al 1983]

    Comparing the amount of dirt is not sufficient because:

    "Soot particles are small, with an average diameter of only 0.1 micron (μm), and so drift down very slowly. They also rise during the daytime as they are heated by the sun, repeatedly delaying their elimination. The calculations showed that the smoke would reach far higher into the upper stratosphere than the sulfate particles that are produced by episodic volcanic eruptions. Sulfate particles are transparent and absorb much less sunlight than soot and are also bigger, typically 0.5 μm."

    100 % of all nuclear attacks where airbursts above large cities so far. What makes you think that this will change significiantly in a nuclear war and that India or Pakistan will waste most of their bombs for bunkers instead?

    "Toon and Turco, along with Charles Bardeen, now at the National Center for Atmospheric Research, modeled what would happen if 50 Hiroshima-size bombs were dropped across the highest population-density targets in Pakistan and if 50 similar bombs were also dropped across India."

    What are you talking about?
    Last edited: May 3, 2017
  12. May 3, 2017 #11


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    The end of Cold War-era US FEMA maps estimating the effects of a full-scale nuclear war are available:
    https://fas.org/nuke/guide/usa/napb-90/index.html (annex A)
    Even though silo installations do get completely plastered (e.g. the map of North Dakota in the above document), pretty much every population centre gets hit.
    Or is that estimate also laughable?
  13. May 3, 2017 #12
    That estimate is laughable.

    It takes 2 correctly functioning warheads to dig out and destroy an ICBM silo, the point of Nuclear parity is it basically OBLITERATES any possibility of "counter cost" strikes (attacking cities). It's because every missile you use to hit a city is 1 silo that survives, and any missiles that survive enables 2nd or tertiary strikes at liberty, which gives you a FIELD ADVANTAGE on the conventional battlefield.

    If the enemy has no more nukes, but you have nukes, then when you invaded western Russia and have their forces bottled up in Poland, a few nuclear strikes wipes out their millions of soldiers and breaks their line.

    This is all very "at a glance" but it's part of the nuclear posturing.

    We haven't even considered the functionality of the warheads, I've heard one estimate at 75%. Meaning 25% are now known to be duds, this is calculated at Livermore labs as they are the stewards of the Nuclear Stockpile:


    So without assurances of how many Nukes might actually work, the most important targets might have to be given 3 warheads.

    Now, on to discussions of other targets such as Airports, typically this role is given to submarines, but their missiles are typically in the 100kt ranges. Enough to devastate an airport, but airports are a bit like shields, so what happens when an explosion hits a shield, it just gets deflected, in this case straight-up. So you can wipe out an airport, but airports are rather giant deflectors, any nuke hitting those are not likely to be damaging the surrounding cities very much.

    The airports given priority are command and control, for instance can Air Force 1 & 2 land there?

    And as far as FAS is concerned, I like their work, but they aren't exactly an unbiased source.

    No one should be "pro-nuclear weapons" but FAS is decisively anti-Nuclear weapons and their arguments are designed to maximize the apparent damage to civilians and ignore reality.

    The reason I think this matters is because the reality is "better" than the worse case scenarios and therefore it's "worse".

    Let me analogize.

    If people said: World War 1 will destroy the Earth, that's a pretty worst case scenario, and no one would or should take it seriously, and the commanders in charge definitely won't.

    But had realists said "World War 1 will kill 10s of millions of people and we'll be locked in a mobilization-trap like two pitbulls biting eachother in the mouth".

    Perhaps cooler-heads would have prevailed and prevented the war.

    Having a realistic view of what Nuclear War actually would be like, would be the best possibility for preventing it. And the realistic scenario is that Nuclear War would largely be a counter-value artillery duel, and it will be a repetitious round of strike and counter strike while countries use their massive conventional forces to try and control strategic resources and control their populations from revolutionizing against the governments.

    It would be a state of massive military terrorism (think of the Confederacy from 1862-1865 or Nazi Germany from 1942-1945) and it will be forced rounds of nuclear strikes, each round having little respite where conventional forces frantically operate to try and rebuild their nuclear arsenal for a knock out blow.

    It may drift into Counter-cost strikes (against cities) depending on how much cities begin to support Nuclear industrial operations. but most likely it'd be remain isolated to military/industrial targets until the end, when maybe the losing side does a counter cost for the h3ll of it.

    By then I'd hope that people would have woken up to the problem and built massive civilian defense structures.

    Which currently are limited by treaty.
  14. May 3, 2017 #13
    1983, 1985, getting really close in splitting hairs, but thanks for the counter example. The argument is still hogwash based on what we know of Volcanoes just as an example.

    As for India and Pakistan, they would likely do counter-cost, their postures are hard to determine, I've seen it argued India has changed their posture to first-strike and therefore would be counter-value (to prevent the high cost of a Pakistani nuke hitting a city).

    But there really isn't a lot of external consequences of a few Indian cities going up in hellfire.

    It might even improve the world's atmosphere by shutting down one of the biggest polluters on the planet.
  15. May 3, 2017 #14
    Oh and regarding soot...which I find fascinating because I used to work as a firefighter, and worked under those giant pyrocumulus clouds as they build-up.

    That soot definitely has as much if not more heat-energy pumped into it than a nuclear blast, and no one is crying about nuclear winter from the tens of MILLIONS of acres that catch fire every year.

    As far as Type 1 fires go, which are large enough to usually have caused pyrocumulus, we get several a year at least and they burn 100s thousands of acres, often woodlands because of the nature of what makes it Type1. And that is getting pushed right up to as high as 50,000 feet. Easily 30,000 feet.

    So I fail to see how a mushroom cloud that rises only 10,000 feet is going to eject more soot into the stratosphere (at 70,000+).
  16. May 3, 2017 #15

    jim mcnamara

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    @IDNeon -

    Another counterexample and PLEASE cite reviewed papers, no more hand-wavy stuff like 'laughable' to dispute something. Cite peer reviewed literature, and do not claim there is no research to support the nuclear winter concept:


    Model shows mid-July temperatures at mid-latitudes lower by 15°C -20°C. Read the paper. Please.
  17. May 3, 2017 #16
    Oh Jeeze, this paper doesn't seem to be about Nuclear warfare at all...and me being hand wavy was in regards to to FAS by the way, which isn't really known for being a research institution in the matters of nuclear warfare.) I can hold a cogent argument about the ENTIRE subject matter off the top of my head.

    The paper you just cited in the abstract has to do with just smoke. I never denied smoke will change albedo. But that Nuclear Bombs won't add much more smoke than already is added by regular fires.

    And causality and correlation with climate is so difficult, if only Climate science were that easy, then Fox News would be a university.

    Furthermore: The paper you cited is from 1987, continuing to qualify my statement that the Nuclear Winter theory popped-up in 1980s and was hair-brained and not real science.

    Lastly: Their claims are that Some 60 to 180 Teragrams of smoke will be blasted into the atmosphere.

    On what basis? Can we compare that with how much smoke goes up in pyrocumulus every year during fire season?

    Is it a reasonable assumption to make based on observed Nuclear tests?

    Remember, the smoke column of a Nuclear blast is much smaller than that of a Pyrocumulus, so I don't just correlate the two willy-nilly...I make the distinction because one event is MANY times greater than the other event. So it's a far fetch to claim the lesser event will have MORE impact.
  18. May 3, 2017 #17


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    Unless I'm missing something - the FEMA report is available on their website, but they're not the authors, so how is that pertinent?
  19. May 3, 2017 #18
    Depends, are you limiting your claims to the FEMA report? Which is itself a biased bureaucracy that is seeking funding in a competitive legislative budgeting cycle? What gives FEMA authority on the matter? I trust the actual war-planners' views of the conflict, and the judgment made by the testers at the actual testing grounds, not the 3rd party adjustments made over decades later to try and justify their budgets.

    Not to throw FEMA entirely under the bus...but just saying.

    I recognize there's a push-pull going on in the debate among the scientific community about this, I'm not by any means saying there's a consensus. But what I am saying is a few things:

    1) The Nuclear Winter theory was largely born out of the 1980s when other radical claims like the Van Allen's belt catching fire were soundly defeated.

    2) The evidence of it is based on absurd asumptions (note the wide variability of 60-180 Tg of smoke in the Stratosphere, well first that's a big margin of error, second where's the comparison to known actual values of smoke making it into the stratosphere?)

    3) The proponents of Nuclear Winter theory were largely agenda seekers in government, seeking their agenda. Just like the war lobby is a real thing, just like MIC is real and seeks its own agenda, etc., etc.

    But the other lobbies didn't really take it into account.

    Not just in America, Russia disregarded it as total Sh---.

    Russia believes they can win a Nuclear War, and even states in their declassified soviet posture from the 1980s that a Nuclear War would be NO MORE devastating than WW2 and so may be preferred to some other things. They DO NOT mention "Nuclear Winter destroying Earth".
  20. May 3, 2017 #19
    One last caveat to this discussion.

    "MAD" is not mutual and certainly not assured.

    Russia doesn't live by "MAD" that's an American propganda concept that exists to excuse the reason why America does not abide by the treaty limiting each Nuclear power to 1 city that can be protected by Ballistic Missile Defense and be thoroughly provisioned for civil defense.

    America opted out of that because in American politics how do you decide which city survives and all others are destroyed.

    For Russia this is easy, Moscow...and they can house some estimated 5-10 million people in Nuclear Bunkers in Moscow.

    Russia doesn't think Mutually Assured Destruction is a real thing...it doesn't exist in their language or doctrines.

    My point to this tangent is that a lot of what we hear about Nuclear war is driven by laziness on the part of politicians. MAD, Nuclear Winter, etc, eliminates the need for REAL Nuclear policy at a public level. They continue to let the Pentagon do its thing, but they don't have to confront public backlash over those DoD decisions. Because we'll all be dead...so they say.
  21. May 3, 2017 #20

    jim mcnamara

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