5 ms·

> These folks were planning to release 500g of sulfur dioxide — that’s completely insignificant, right? Just a POC? Yes, that is a practically undetectable add

by jxf 4y ago

> These folks were planning to release 500g of sulfur dioxide — that’s completely insignificant, right? Just a POC? Yes, that is a practically undetectable addition of SO2. For reference, the US emitted approximately 2M tons of SO2 in 2019; that's about 1.8 billion kg. The 500g here is approximately one part in one billion. If the startup added 500g of SO2 every single day for the next 10,000 years, they would add 1% to the total SO2 emissions of just 2019.

perihelions 4y ago
Keep in mind that ordinary SO₂ pollution doesn't make its way into the stratosphere. It's a different problem.
- jxf 4y ago
  You're 100% right; I'm just drawing a comparison for the sake of scale.
- mcv 4y ago
  Isn't that kind of SO2 release the cause of acid rain? Because that's not good. If we're going to release those millions of tons of CO2 into the atmosphere anyway, maybe it makes sense to release it into the stratosphere instead, to duplicate the cooling effect of the volcano. Although that's not so easily done. Also, apart from a cooling effect, what other effects did that volcanic release of SO2 have?
  - jxf 4y ago
    The cooling effect comes in part from a reduction of light reaching the Earth's surface, lowering the amount of energy that plants receive to grow.
    - mcv 4y ago
      I looked it up on Wikipedia: > The powerful eruption of such an enormous volume of lava and ash injected significant quantities of aerosols and dust into the stratosphere. Sulfur dioxide oxidized in the atmosphere to produce a haze of sulfuric acid droplets, which gradually spread throughout the stratosphere over the year following the eruption. The injection of aerosols into the stratosphere is thought to have been the largest since the 1883 eruption of Krakatoa, with a total mass of SO 2 of about 17,000,000 t (19,000,000 short tons) being injected – the largest volume ever recorded by modern instruments (see chart and figure). > Satellite measurements of ash and aerosol emissions from Mount Pinatubo This very large stratospheric injection resulted in a volcanic winter, a reduction in the normal amount of sunlight reaching the Earth's surface by roughly 10% (see figure). This led to a decrease in Northern Hemisphere average temperatures of 0.5–0.6 °C (0.9–1.1 °F) and a global decrease of about 0.4 °C (0.7 °F).[21][22] At the same time, the temperature in the stratosphere rose to several degrees higher than normal, due to the absorption of radiation by the aerosol. The stratospheric cloud from the eruption persisted in the atmosphere for three years. The eruption, while not directly responsible, may have played a part in the formation of the 1993 Storm of the Century.[23] > The eruption had a significant effect on ozone levels in the atmosphere, causing a large increase in the destruction rate of ozone. Ozone levels at middle latitudes reached their lowest recorded levels, while in the Southern Hemisphere winter of 1992, the ozone hole over Antarctica reached its largest ever size until then, with the fastest recorded ozone depletion rates. The eruption of Mount Hudson in Chile in August 1991 also contributed to southern hemisphere ozone destruction, with measurements showing a sharp decrease in ozone levels at the tropopause when the aerosol clouds from Pinatubo and Hudson arrived. Another noticeable effect of the dust in the atmosphere was the appearance of lunar eclipses. Normally even at mid-eclipse, the moon is still visible although much dimmed, whereas in the year following the Pinatubo eruption, the moon was hardly visible at all during eclipses, due to much greater absorption of sunlight by dust in the atmosphere. It has also been suggested that excess cloud condensation nuclei from the eruption were responsible for the "Great Flood of 1993" in the Midwestern United States. So while no effect on plant growth is mentioned, it may have caused a major storm, a major flood, and enlarged the hole in the ozone layer. Sounds like a bad idea overall. Especially since that reduction in temperature was only temporary. For this approach to have any long-term impact, you'd have to keep injecting SO2 into the stratosphere every year.
      - perihelions 4y ago
        - "Especially since that reduction in temperature was only temporary." It still seems a useful tool to have in reserve, if you later decide you want to halt a runaway feedback loop linked to temperature. E.g. an albedo feedback from melting sea ice [0], or methane clathrates thawing from a warming ocean [1]. Temporary changes can leave permanent effects. It'd be nice to R&D this stuff sooner, and not really need it, then delay and debate and suddenly there's a black-swan planetary apocalypse and the one tool you need right now isn't available. [0] https://en.wikipedia.org/wiki/Ice%E2%80%93albedo_feedback?useskin=vector https://en.wikipedia.org/wiki/Ice%E2%80%93albedo_feedback?us... [1] https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis?useskin=vector https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis?usesk...
      - BurningFrog 4y ago
        The fact that the effect is temporary is one of the best parts of this scheme. If it turns out to have unforeseen bad effects, just stop doing it, and it will be gone.
  - BurningFrog 4y ago
    I believe SO₂ in the stratosphere is above the rain cycle and does not affect it. It also breaks down in 1-2 years.
ido 4y ago
OT but your post made me learn that in English "Tonne" and "Ton" denote two different units!
- kube-system 4y ago
  “Ton” itself can also refer two different units: The 2240 lb British long ton and the 2000 lb American short ton. And “metric ton” refers to “tonne”. Tl;dr: a ton of confusion.
  - car 4y ago
    Funny, as "Tonne" is the german word for barrel or cask. And also for a metric ton, equaling 1000 kilograms, or 2000 german "Pfund", i.e. pounds.
    - _ikke_ 4y ago
      Besides these things, in Dutch, a ton can also mean €100.000.
      - radiowave 4y ago
        Same in the UK for £100, and also for driving at 1oo mph.
    - jimnotgym 4y ago
      So an American short ton and a German metric tonne are both 2000 pounds....but the pounds are not the same!
    - rmccue 4y ago
      Same origin; the extant word in English is "tun" for the barrel, and a ton was equal to the mass of the contents of a tun. https://en.wiktionary.org/wiki/ton#English https://en.wiktionary.org/wiki/ton#English https://en.wiktionary.org/wiki/tun#English https://en.wiktionary.org/wiki/tun#English https://www.etymonline.com/word/ton#etymonline_v_15357 https://www.etymonline.com/word/ton#etymonline_v_15357
theonlybutlet 4y ago
It's more a case of, what would happen if everyone did it? Those farmers all washing an insignificant amount of pesticide/fertilizer into a river, all add up. That's why we have environmental laws and this is pollution.
onion2k 4y ago
If it's so insignificant why not do it in the US then?
- concordDance 4y ago
  Because the regulations don't allow it. Laws and regs are very blunt and don't take into account every possible case, like 500g into stratosphere.

by jxf 4y ago

perihelions 4y ago

Keep in mind that ordinary SO₂ pollution doesn't make its way into the stratosphere. It's a different problem.

jxf 4y ago
You're 100% right; I'm just drawing a comparison for the sake of scale.
mcv 4y ago
Isn't that kind of SO2 release the cause of acid rain? Because that's not good. If we're going to release those millions of tons of CO2 into the atmosphere anyway, maybe it makes sense to release it into the stratosphere instead, to duplicate the cooling effect of the volcano. Although that's not so easily done. Also, apart from a cooling effect, what other effects did that volcanic release of SO2 have?
- jxf 4y ago
  The cooling effect comes in part from a reduction of light reaching the Earth's surface, lowering the amount of energy that plants receive to grow.
  - mcv 4y ago
    I looked it up on Wikipedia: > The powerful eruption of such an enormous volume of lava and ash injected significant quantities of aerosols and dust into the stratosphere. Sulfur dioxide oxidized in the atmosphere to produce a haze of sulfuric acid droplets, which gradually spread throughout the stratosphere over the year following the eruption. The injection of aerosols into the stratosphere is thought to have been the largest since the 1883 eruption of Krakatoa, with a total mass of SO 2 of about 17,000,000 t (19,000,000 short tons) being injected – the largest volume ever recorded by modern instruments (see chart and figure). > Satellite measurements of ash and aerosol emissions from Mount Pinatubo This very large stratospheric injection resulted in a volcanic winter, a reduction in the normal amount of sunlight reaching the Earth's surface by roughly 10% (see figure). This led to a decrease in Northern Hemisphere average temperatures of 0.5–0.6 °C (0.9–1.1 °F) and a global decrease of about 0.4 °C (0.7 °F).[21][22] At the same time, the temperature in the stratosphere rose to several degrees higher than normal, due to the absorption of radiation by the aerosol. The stratospheric cloud from the eruption persisted in the atmosphere for three years. The eruption, while not directly responsible, may have played a part in the formation of the 1993 Storm of the Century.[23] > The eruption had a significant effect on ozone levels in the atmosphere, causing a large increase in the destruction rate of ozone. Ozone levels at middle latitudes reached their lowest recorded levels, while in the Southern Hemisphere winter of 1992, the ozone hole over Antarctica reached its largest ever size until then, with the fastest recorded ozone depletion rates. The eruption of Mount Hudson in Chile in August 1991 also contributed to southern hemisphere ozone destruction, with measurements showing a sharp decrease in ozone levels at the tropopause when the aerosol clouds from Pinatubo and Hudson arrived. Another noticeable effect of the dust in the atmosphere was the appearance of lunar eclipses. Normally even at mid-eclipse, the moon is still visible although much dimmed, whereas in the year following the Pinatubo eruption, the moon was hardly visible at all during eclipses, due to much greater absorption of sunlight by dust in the atmosphere. It has also been suggested that excess cloud condensation nuclei from the eruption were responsible for the "Great Flood of 1993" in the Midwestern United States. So while no effect on plant growth is mentioned, it may have caused a major storm, a major flood, and enlarged the hole in the ozone layer. Sounds like a bad idea overall. Especially since that reduction in temperature was only temporary. For this approach to have any long-term impact, you'd have to keep injecting SO2 into the stratosphere every year.
    - perihelions 4y ago
      - "Especially since that reduction in temperature was only temporary." It still seems a useful tool to have in reserve, if you later decide you want to halt a runaway feedback loop linked to temperature. E.g. an albedo feedback from melting sea ice [0], or methane clathrates thawing from a warming ocean [1]. Temporary changes can leave permanent effects. It'd be nice to R&D this stuff sooner, and not really need it, then delay and debate and suddenly there's a black-swan planetary apocalypse and the one tool you need right now isn't available. [0] https://en.wikipedia.org/wiki/Ice%E2%80%93albedo_feedback?useskin=vector https://en.wikipedia.org/wiki/Ice%E2%80%93albedo_feedback?us... [1] https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis?useskin=vector https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis?usesk...
    - BurningFrog 4y ago
      The fact that the effect is temporary is one of the best parts of this scheme. If it turns out to have unforeseen bad effects, just stop doing it, and it will be gone.
- BurningFrog 4y ago
  I believe SO₂ in the stratosphere is above the rain cycle and does not affect it. It also breaks down in 1-2 years.

ido 4y ago

OT but your post made me learn that in English "Tonne" and "Ton" denote two different units!

kube-system 4y ago
“Ton” itself can also refer two different units: The 2240 lb British long ton and the 2000 lb American short ton. And “metric ton” refers to “tonne”. Tl;dr: a ton of confusion.
- car 4y ago
  Funny, as "Tonne" is the german word for barrel or cask. And also for a metric ton, equaling 1000 kilograms, or 2000 german "Pfund", i.e. pounds.
  - _ikke_ 4y ago
    Besides these things, in Dutch, a ton can also mean €100.000.
    - radiowave 4y ago
      Same in the UK for £100, and also for driving at 1oo mph.
  - jimnotgym 4y ago
    So an American short ton and a German metric tonne are both 2000 pounds....but the pounds are not the same!
  - rmccue 4y ago
    Same origin; the extant word in English is "tun" for the barrel, and a ton was equal to the mass of the contents of a tun. https://en.wiktionary.org/wiki/ton#English https://en.wiktionary.org/wiki/ton#English https://en.wiktionary.org/wiki/tun#English https://en.wiktionary.org/wiki/tun#English https://www.etymonline.com/word/ton#etymonline_v_15357 https://www.etymonline.com/word/ton#etymonline_v_15357

theonlybutlet 4y ago

It's more a case of, what would happen if everyone did it? Those farmers all washing an insignificant amount of pesticide/fertilizer into a river, all add up. That's why we have environmental laws and this is pollution.

onion2k 4y ago

If it's so insignificant why not do it in the US then?

concordDance 4y ago
Because the regulations don't allow it. Laws and regs are very blunt and don't take into account every possible case, like 500g into stratosphere.