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Talk:Nuclear winter

Latest comment: 27 days ago by NPguy in topic Soot is assumed to form over 'rural missile silos'?
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Pinatubo section was removed, as "unrelated"

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However as the very last sentence of this section sums-up why it does relate to fire-formed aerosols, the rationale behind its removal is both unsubstantiated and plainly contradicted by the very text that was removed. Read: This...also naturally results as a product of other aerosols that are not emitted by volcanoes, such as man-made "moderately thick smoke loading" pollution, as the same mechanism, the "aerosol direct radiative effect" is behind both.

Eruption of Mt. Pinatubo and agriculture

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See also: photosynthesis
 
A Space Shuttle (Mission STS-43) photograph of the Earth over South America taken on August 8, 1991, which captures the double layer of Pinatubo aerosol clouds (dark streaks) above lower cloud tops.

The eruption of the Philippines volcano - Mount Pinatubo in June 1991 ejected roughly 10 km3 (2.4 cu mi) of magma and "17,000,000 metric tons"(17 teragrams) of sulfur dioxide SO2 into the air, introducing ten times as much total SO2 as the 1991 Kuwaiti fires,[1] mostly during the explosive Plinian/Ultra-Plinian event of June 15, 1991, creating a global stratospheric SO2 haze layer which persisted for years. This resulted in the global average temperature dropping by about 0.5 °C (0.9 °F).[2] As volcanic ash falls out of the atmosphere rapidly,[3] the negative agricultural effects of the eruption were largely immediate and localized to a relatively small area in close proximity to the eruption, as they were caused by the resulting thick ash cover that resulted.[4][5] Globally however, despite a several-month 5% drop in overall solar irradiation, and a reduction in direct sunlight by 30%,[6] there was no negative impact to global agriculture.[7][8] Surprisingly, a 3-4 year[9] increase in global Agricultural productivity and forestry growth was observed, excepting boreal forest regions.[10]

 
Under more-or-less direct sunlight, dark shadows that limit photosynthesis are cast onto understorey leaves. Within the thicket, very little light can enter.

The means by which this was discovered, is that initially at the time, a mysterious drop in the rate at which carbon dioxide (CO2) was filling the atmosphere was observed, which is charted in what is known as the "Keeling Curve".[11] This led numerous scientists to assume that this reduction was due to the lowering of the Earth's temperature, and with that, a slow down in plant and soil respiration, indicating a deleterious impact to global agriculture from the volcanic haze layer.[7][12] However upon actual investigation, the reduction in the rate at which carbon dioxide filled the atmosphere did not match up with the hypothesis that plant respiration rates had declined.[13][14] Instead the advantageous anomaly was relatively firmly[15] linked to an unprecedented increase in the growth/net primary production,[16] of global plant life, resulting in the increase of the carbon sink effect of global photosynthesis.[7][17] The mechanism by which the increase in plant growth was possible, was that the 30% reduction of direct sunlight can also be expressed as an increase or "enhancement" in the amount of diffuse sunlight.[7][13][18][19]

 
Well lit understorey areas due to overcast clouds creating diffuse/soft sunlight conditions, that permits photosynthesis on leaves under the canopy.

With, owing to its intrinsic nature, can illuminate under-canopy leaves permitting more efficient total whole-plant photosynthesis than would otherwise be the case.[7][20] In stark contrast to the effect of totally clear skies and the direct sunlight that results from it, which casts shadows onto understorey leaves, strickly limiting plant photosynthesis to the top canopy layer.[7][21] This increase in global agriculture from the volcanic haze layer also naturally results as a product of other aerosols that are not emitted by volcanoes, such as man-made "moderately thick smoke loading" pollution, as the same mechanism, the "aerosol direct radiative effect" is behind both.[10][22][23]

References

  1. ^ John C McCain; Muhammad Sadiq; M Sadiq (1993). The Gulf War Aftermath: An Environmental Tragedy. Springer. p. 60. ISBN 0-792-32278-9.
  2. ^ "Mt. Pinatubo's cloud shades global climate". Science News. Retrieved 2010-03-07.
  3. ^ When Thunderstorms Get Down and Dirty. USGS
  4. ^ Socioeconomic Impacts of the Mount Pinatubo EruptionBy Remigio A. Mercado,1 Jay Bertram T. Lacsamana,1 and Greg L. Pineda11 National Economic and Development Authority, Region III, San Fernando, Pampanga, Philippines
  5. ^ Mt. pinatubo (LK): Biosphere Mt. Pinatubo Cycle A1: Individual response: Biosphere. Larissa Karan
  6. ^ Cooling Following Large Volcanic Eruptions Corrected for the Effect of Diffuse Radiation on Tree Rings. Alan Robock, 2005. See Figure 1 for a graphic of the recorded change in solar iiradiation
  7. ^ a b c d e f Large Volcanic Eruptions Help Plants Absorb More Carbon Dioxide From the Atmosphere December 10, 2001. NASA
  8. ^ LARGE VOLCANIC ERUPTIONS HELP PLANTS ABSORB MORE CARBON DIOXIDE FROM THE ATMOSPHERE
  9. ^ The effects and consequences of very large explosive volcanic eruptions DOI: 10.1098/rsta.2006.1814 Published 15 August 2006
  10. ^ a b Evaluating aerosol direct radiative effects on global terrestrial ecosystem carbon dynamics from 2003 to 2010. Chen et al., Tellus B 2014; 66, 21808, Published by the international meteorological institute in Stockholm.
  11. ^ Cooling Following Large Volcanic Eruptions Corrected for the Effect of Diffuse Radiation on Tree Rings. Alan Robock, 2005. See Figure 2 for a record of this
  12. ^ LARGE VOLCANIC ERUPTIONS HELP PLANTS ABSORB MORE CARBON DIOXIDE FROM THE ATMOSPHERE
  13. ^ a b Roles of volcanic eruptions, aerosols and clouds in global carbon cycle. American Geophysical Union, Fall Meeting 2001, abstract #B51A-0194
  14. ^ Response of a Deciduous Forest to the Mount Pinatubo Eruption: Enhanced Photosynthesis. Gu et al., 28 March 2003 Journal of Science Vol 299
  15. ^ Volcanic Eruptions (Biological Impact) -- Summary
  16. ^ http://earthobservatory.nasa.gov/Features/GlobalGarden/ Global Garden gets greener. NASA 2003
  17. ^ LARGE VOLCANIC ERUPTIONS HELP PLANTS ABSORB MORE CARBON DIOXIDE FROM THE ATMOSPHERE
  18. ^ Cooling Following LargeVolcanic Eruptions Corrected for the Effect of Diffuse Radiation on Tree Rings. Alan Robock, 2005. Figure 1
  19. ^ LARGE VOLCANIC ERUPTIONS HELP PLANTS ABSORB MORE CARBON DIOXIDE FROM THE ATMOSPHERE
  20. ^ LARGE VOLCANIC ERUPTIONS HELP PLANTS ABSORB MORE CARBON DIOXIDE FROM THE ATMOSPHERE
  21. ^ LARGE VOLCANIC ERUPTIONS HELP PLANTS ABSORB MORE CARBON DIOXIDE FROM THE ATMOSPHERE
  22. ^ Impact of atmospheric aerosol light scattering and absorption on terrestrial net primary productivity, Cohan et al. GLOBAL BIOGEOCHEMICAL CYCLES 2002 VOL. 16, NO. 4, 1090, doi:10.1029/2001GB001441
  23. ^ Direct observations of the effects of aerosol loading on net ecosystem CO2 exchanges over different landscapes. Niyogi et al. Geophysical Research Letters Volume 31, Issue 20, October 2004 doi:10.1029/2004GL020915

Professor Fromm and the empirical data

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The Beaver complex fire cloud stem, taken below the cloud cap. Oregon, 2014. An F-15C Eagle accompanies the plane which submitted its photos to NASA.[1]. In total 35,302 acres burnt over a number of days in the area.[2] The 2003 Canberra wildfiress, which produced black hail and the Aug 1 2010 Russian wildfires that Meteorologist Michael Fromm at the Naval Research Laboratory has definitively determined injected aerosols into the stratosphere with the aid of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite, Terra satellite, Aqua satellite & SAGE III cloud reached 12 kilometers. Fromm notes that "pyrocumulonimbus clouds are probably not unusual",however notably they are not "accounted for in global warming climate models". "Just how frequently pyrocumulonimbus clouds form and how much they contribute to aerosols in the stratosphere are questions that will require more observations to answer." [3]
 
June 19, 2013 the Colorado West Fork Complex fire lofted smoke plumes as high as 13.5 kilometers (8.4 miles) into the atmosphere. Fromm's use of the Satellite observations also show that smoke reached European airspace by June 24.

References

  1. ^ Evolution of Pyrocumulus over California August 6, 2014
  2. ^ Beaver Complex
  3. ^ Russian Firestorm: Finding a Fire Cloud from Space

Cut down on the repetition of the same papers

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Bearing this in mind: The 1988 Air Force Geophysics Laboratory publication An assessment of global atmospheric effects of a major nuclear war by Muench, H. Stuart et al. contains a chronology and review of the major reports on the nuclear winter hypothesis from 1983-86. In general these reports arrive at similar conclusions as they are based on the same "assumptions, the same basic data" with minor model-code differences "to arrive at the same answer". They skip the modeling steps of assessing the possibility of fire and the initial fire plumes and instead start the modeling process with a "spatially uniform" "soot cloud" which has found its way into the atmosphere.[1]

With that in mind, is there any objections to tabulating the results of the various papers and only giving them ink when they are novel in some way that is not possible to convey in the proposed table?

References

  1. ^ An assessment of global atmospheric effects of a major nuclear war pg 3-10

Wiki Education assignment: Cold War Science

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  This article was the subject of a Wiki Education Foundation-supported course assignment, between 18 January 2022 and 6 May 2022. Further details are available on the course page. Student editor(s): Clementine1434 (article contribs).

Soot is assumed to form over 'rural missile silos'?

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Latest comment: 27 days ago2 comments2 people in discussion

Is this a typo? It makes no sense, does it? Did they maybe mean 'rural grain silos' or something of that kind? I've googled the term in quotation marks and there are very few hits and many of them are actually the same text as in the article, just on different platforms. --Felix Tritschler (talk) 13:53, 28 November 2024 (UTC)Reply

No typo. Missile silos tend to be in sparsely populated areas and would be prime _targets of nuclear attack. NPguy (talk) 16:49, 28 November 2024 (UTC)Reply
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