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>So, this event could have put huge amounts of carbon dioxide into the air, causing an intense bout of global warming. This leap at the end of the article is s

>So, this event could have put huge amounts of carbon dioxide into the air, causing an intense bout of global warming. This leap at the end of the article is strange and comes with zero scientific backup. As far as the studies I’ve read, volcanic CO2 emissions are not large enough to cause greenhouse effects. SO2 and particulate emissions would actually create more of a cooling effect.

AbrahamParangi 3y ago
Volcanic activity is also the prime suspect in the Permian extinction, I don’t think the author’s statement is out of line. It’s conjecture anyway because the details are murky.
pfdietz 3y ago
CO2 emissions during flood basalts can be enormous. One estimate I recall from the P-T boundary had CO2 levels going up to as much as 32,000 ppm. Carbon isotopes go crazy there. Granted, the magma of the Siberian Traps intruded right into the middle of a sedimentary basin containing enormous quantities of fossil carbon. The cooling effect from SOx and particulates is short lived compared to CO2's warming. Also, heating in the stratosphere from particulates can, if bad enough, cause destruction of the ozone layer.
- phkahler 3y ago
  >> The cooling effect from SOx and particulates is short lived compared to CO2's warming. Sure, but there's also the direct "making things die" effect of SOx. For humans this happens at much lower concentration than CO2, but I can't speak to dinotoxicity.
deleted 3y ago
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jofer 3y ago
First off, SO2 breaks down quickly on geologic timescales. The cooling effect is short-lived. CO2 takes longer to move out of the atmosphere. Next, modern day volcanic emissions aren't major players in current climatic changes, but that's not the case for the past. Large igneous provinces can dramatically alter global climate. CAMP magmatism was extremely widespread and prolific. You don't see the bulk of it at the surface, but large swaths of the eastern US coast and NW African coast are sitting on top of gigantic piles of basalt. However, it's not _only_ CO2 for these large magmatic events. You're also dramatically altering ocean basins. Large igneous provinces are most frequently produced as continents break up. When that happens, you get a new ocean basin, change circulation, split things apart, introduce new species, raise/lower global sea level (ocean basin shape changes), and generally do a whole lot to shake things up. Continents can break up without much magmatic activity as well, but when you have mantle plumes involved in continental breakup, you tend to get the double-whammy of changes in ocean shape + lots of volcanic activity over huge areas. The extinction at ~200Ma (end of the Triassic, though the round number is a concidence) is a great example of magmatic activity having a large effect, but don't forget the impact that changing ocean basin shape/volume has as well. Mass extinctions usually aren't things with single causes. Instead, they're generally the result of a lot of things combining. Folks focus on the impact as the single cause of the K-T extinction, and while there's not doubt that it's what pushed things over the edge, other changes that had been ongoing for millions of years before had already stressed many different global ecosystems. You had major changes in volcanism (another large igneous province occurring during continental breakup, though it's smaller), reconfiguration of ocean basins, and other things occurring at the same time. The timing makes it clear that the impact was the sudden shock, but things were already heavily shaken up before that.
- chrisco255 3y ago
  SO2 does break down within years to co2 and h2o, but if the volcanoes keep spewing the supply keeps getting replenished. There are periods in Earth's history where volcanoes are far more active and continuously so. So not really an open and shut case.
  - selimthegrim 3y ago
    See my submission: https://news.ycombinator.com/item?id=37344251 https://news.ycombinator.com/item?id=37344251

AbrahamParangi 3y ago

Volcanic activity is also the prime suspect in the Permian extinction, I don’t think the author’s statement is out of line. It’s conjecture anyway because the details are murky.

pfdietz 3y ago

CO2 emissions during flood basalts can be enormous. One estimate I recall from the P-T boundary had CO2 levels going up to as much as 32,000 ppm. Carbon isotopes go crazy there. Granted, the magma of the Siberian Traps intruded right into the middle of a sedimentary basin containing enormous quantities of fossil carbon. The cooling effect from SOx and particulates is short lived compared to CO2's warming. Also, heating in the stratosphere from particulates can, if bad enough, cause destruction of the ozone layer.

phkahler 3y ago
>> The cooling effect from SOx and particulates is short lived compared to CO2's warming. Sure, but there's also the direct "making things die" effect of SOx. For humans this happens at much lower concentration than CO2, but I can't speak to dinotoxicity.

deleted 3y ago

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jofer 3y ago

First off, SO2 breaks down quickly on geologic timescales. The cooling effect is short-lived. CO2 takes longer to move out of the atmosphere. Next, modern day volcanic emissions aren't major players in current climatic changes, but that's not the case for the past. Large igneous provinces can dramatically alter global climate. CAMP magmatism was extremely widespread and prolific. You don't see the bulk of it at the surface, but large swaths of the eastern US coast and NW African coast are sitting on top of gigantic piles of basalt. However, it's not _only_ CO2 for these large magmatic events. You're also dramatically altering ocean basins. Large igneous provinces are most frequently produced as continents break up. When that happens, you get a new ocean basin, change circulation, split things apart, introduce new species, raise/lower global sea level (ocean basin shape changes), and generally do a whole lot to shake things up. Continents can break up without much magmatic activity as well, but when you have mantle plumes involved in continental breakup, you tend to get the double-whammy of changes in ocean shape + lots of volcanic activity over huge areas. The extinction at ~200Ma (end of the Triassic, though the round number is a concidence) is a great example of magmatic activity having a large effect, but don't forget the impact that changing ocean basin shape/volume has as well. Mass extinctions usually aren't things with single causes. Instead, they're generally the result of a lot of things combining. Folks focus on the impact as the single cause of the K-T extinction, and while there's not doubt that it's what pushed things over the edge, other changes that had been ongoing for millions of years before had already stressed many different global ecosystems. You had major changes in volcanism (another large igneous province occurring during continental breakup, though it's smaller), reconfiguration of ocean basins, and other things occurring at the same time. The timing makes it clear that the impact was the sudden shock, but things were already heavily shaken up before that.

chrisco255 3y ago
SO2 does break down within years to co2 and h2o, but if the volcanoes keep spewing the supply keeps getting replenished. There are periods in Earth's history where volcanoes are far more active and continuously so. So not really an open and shut case.
- selimthegrim 3y ago
  See my submission: https://news.ycombinator.com/item?id=37344251 https://news.ycombinator.com/item?id=37344251