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Nuclear winter is not a discredited myth. Alan Robock at Rutgers has been conducting climate simulations using a 100 Hiroshimas (~20kT) standard. This is suppos

Nuclear winter is not a discredited myth. Alan Robock at Rutgers has been conducting climate simulations using a 100 Hiroshimas (~20kT) standard. This is supposedly similar to what an India-Pakistan conflict might produce. The results are something more akin to nuclear autumn, but it results in decreased agricultural production between 5-20% in year 5 after the war. The decrease is due primarily to soot in the atmosphere. Recall that nuclear weapons are hot and this causes air to rise. There is a suction effect immediately after the blast and firestorms can form. Here's a link to a summary of results: http://ippnw.org/nuclear-famine.html http://ippnw.org/nuclear-famine.html Simulations of a US-Russian war are more dire, and recent simulations are more in line with TAPPS. TAPPS was never discredited, its results were only somewhat moderated.

jlmorton 9y ago
How could this possibly be true given the fact that there have been >1,000 nuclear tests performed, including devices with orders of magnitude higher yield than in Hiroshima?
- sandworm101 9y ago
  Because those were most all carefully controlled to prevent such damage. Top of the list: those that were above ground were tested above empty terrain. The bomb doesn't create most of the ash. The burning city under the bomb is where the bulk of sun-blocking ash comes from. No city, no ash, no nuclear winter issues.
  - cloakandswagger 9y ago
    I would expect that some of the predicted effects of a "nuclear winter" would start to appear after a series of forest fires--albeit smaller in scope and intensity--but AFAIK this is not the case. What gives?
    - Smudge 9y ago
      Most forest fires don't create strong enough firestorms (if they do at all) to funnel material high enough to have an effect -- most of the ash falls back down in a matter of weeks (even sooner if it gets rained out of the atmosphere). I'd compare nuclear blast firestorms with volcanic eruptions -- we do have a record of eruptions funneling material high enough into the troposphere and stratosphere to have a noticeable, longer-term effect on the climate (over the subsequent months and years).
    - robotresearcher 9y ago
      They aren't usually big enough to get the particulates high enough. But big events can do it: https://en.wikipedia.org/wiki/Year_Without_a_Summer https://en.wikipedia.org/wiki/Year_Without_a_Summer
    - mirimir 9y ago
      There have been "volcanic winter" events. Or at least, reduced insolation for a year or more.
- Smudge 9y ago
  Most tests have been performed underground. And for an above-ground test to cause anything close to a nuclear winter, you need a lot more material than the bomb itself and the soil beneath it. Tons and tons of debris would need to be shot up into the atmosphere. So, the theory of nuclear winter depends on bombs detonating over cities and forests, causing massive amounts of debris, and also inducing firestorms that would act as chimneys for even more smoke and particles to be funneled up into the troposphere and stratosphere.
jandrewrogers 9y ago
How does this square with the global effects of large volcanic eruptions? The largest eruption in the 20th century exceeded the yield of the combined Soviet and US nuclear arsenals at their Cold War peak by an order of magnitude, yet the global effects were mild. Interesting trivia: the largest volcanic explosion of the 20th century is a volcano in the US that most people have never heard of, Novarupta in 1912.
- gregpilling 9y ago
  https://en.wikipedia.org/wiki/Novarupta https://en.wikipedia.org/wiki/Novarupta link for the lazy
- cocoablazing 9y ago
  Volcanic eruption energy is partitioned between thermal and mechanical energy. The mechanical energy is distributed between translation (ejecta) and vibrational (tremors). These proportions vary significantly between volcanoes and eruptions. So, perhaps little of the energy is imparted to bring cooling aerosols and particles into the high atmosphere. A limited nuclear exchange between RF/USA could extend to all large munitions stores, rocket stores, and petrochemical stores. All stores of nuclear launchers, warheads, and supplies intended for strategic war could be targeted. Imagine all significant above-ground petroleum storage in RF/USA - large petroleum producers - is ignited. All counterforce sorties against targets near wooded areas will result in large forest fires.
  - jandrewrogers 9y ago
    "Imagine all significant above-ground petroleum storage in RF/USA - large petroleum producers - is ignited." During the First Gulf War, the uncontrolled oil fires in Kuwait were burning at a rate equivalent to 30% of all US consumption. Nothing remotely resembling a climate apocalypse occurred; major volcanic eruptions have far greater effects. Empirically, it seems highly improbable that repeating that experiment on modestly larger scale will unleash a global apocalypse. It isn't a convincing argument based on the evidence. The above-ground petroleum storage facilities only hold days worth of oil that we are going to burn anyway.
eighthnate 9y ago
> Nuclear winter is not a discredited myth. It has been discredited. Even Sagan admitted as much. The idea that all humanity/life would end has been discredited. Billions would surely die, but millions of humans would survive.

jlmorton 9y ago

How could this possibly be true given the fact that there have been >1,000 nuclear tests performed, including devices with orders of magnitude higher yield than in Hiroshima?

sandworm101 9y ago
Because those were most all carefully controlled to prevent such damage. Top of the list: those that were above ground were tested above empty terrain. The bomb doesn't create most of the ash. The burning city under the bomb is where the bulk of sun-blocking ash comes from. No city, no ash, no nuclear winter issues.
- cloakandswagger 9y ago
  I would expect that some of the predicted effects of a "nuclear winter" would start to appear after a series of forest fires--albeit smaller in scope and intensity--but AFAIK this is not the case. What gives?
  - Smudge 9y ago
    Most forest fires don't create strong enough firestorms (if they do at all) to funnel material high enough to have an effect -- most of the ash falls back down in a matter of weeks (even sooner if it gets rained out of the atmosphere). I'd compare nuclear blast firestorms with volcanic eruptions -- we do have a record of eruptions funneling material high enough into the troposphere and stratosphere to have a noticeable, longer-term effect on the climate (over the subsequent months and years).
  - robotresearcher 9y ago
    They aren't usually big enough to get the particulates high enough. But big events can do it: https://en.wikipedia.org/wiki/Year_Without_a_Summer https://en.wikipedia.org/wiki/Year_Without_a_Summer
  - mirimir 9y ago
    There have been "volcanic winter" events. Or at least, reduced insolation for a year or more.
Smudge 9y ago
Most tests have been performed underground. And for an above-ground test to cause anything close to a nuclear winter, you need a lot more material than the bomb itself and the soil beneath it. Tons and tons of debris would need to be shot up into the atmosphere. So, the theory of nuclear winter depends on bombs detonating over cities and forests, causing massive amounts of debris, and also inducing firestorms that would act as chimneys for even more smoke and particles to be funneled up into the troposphere and stratosphere.

jandrewrogers 9y ago

How does this square with the global effects of large volcanic eruptions? The largest eruption in the 20th century exceeded the yield of the combined Soviet and US nuclear arsenals at their Cold War peak by an order of magnitude, yet the global effects were mild. Interesting trivia: the largest volcanic explosion of the 20th century is a volcano in the US that most people have never heard of, Novarupta in 1912.

gregpilling 9y ago
https://en.wikipedia.org/wiki/Novarupta https://en.wikipedia.org/wiki/Novarupta link for the lazy
cocoablazing 9y ago
Volcanic eruption energy is partitioned between thermal and mechanical energy. The mechanical energy is distributed between translation (ejecta) and vibrational (tremors). These proportions vary significantly between volcanoes and eruptions. So, perhaps little of the energy is imparted to bring cooling aerosols and particles into the high atmosphere. A limited nuclear exchange between RF/USA could extend to all large munitions stores, rocket stores, and petrochemical stores. All stores of nuclear launchers, warheads, and supplies intended for strategic war could be targeted. Imagine all significant above-ground petroleum storage in RF/USA - large petroleum producers - is ignited. All counterforce sorties against targets near wooded areas will result in large forest fires.
- jandrewrogers 9y ago
  "Imagine all significant above-ground petroleum storage in RF/USA - large petroleum producers - is ignited." During the First Gulf War, the uncontrolled oil fires in Kuwait were burning at a rate equivalent to 30% of all US consumption. Nothing remotely resembling a climate apocalypse occurred; major volcanic eruptions have far greater effects. Empirically, it seems highly improbable that repeating that experiment on modestly larger scale will unleash a global apocalypse. It isn't a convincing argument based on the evidence. The above-ground petroleum storage facilities only hold days worth of oil that we are going to burn anyway.

eighthnate 9y ago

> Nuclear winter is not a discredited myth. It has been discredited. Even Sagan admitted as much. The idea that all humanity/life would end has been discredited. Billions would surely die, but millions of humans would survive.