# Would a massive volcanic eruption significantly mitigate global warming? **URL:** \ **Category:** Factual Questions\ **Created:** [July 31, 2009, 7:40pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908 "2009-07-31T19:40:59Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![An\_Gadai](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@An\_Gadai](https://boards.straightdope.com/u/An_Gadai)\ **Post date:** [July 31, 2009, 7:40pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/1 "2009-07-31T19:40:59Z")
I’ve heard that massive volcanic eruptions in the past have had a significant short or medium term effect on the global climate. Would a similar eruption nowadays have a significant effect on global warming? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 31, 2009, 7:49pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/2 "2009-07-31T19:49:58Z")
In the short term, maybe, but in the long run, it’d have no effect at best, or even make things worse. If we don’t do anything else about global warming, you’d need an ever-increasing number of volcanoes to keep up. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [July 31, 2009, 7:53pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/3 "2009-07-31T19:53:35Z")
After Tambora blew in 1815, we had ‘the year without a summer’ of 1816; ditto (if I remember Barbara Tuchman correctly) after a volcano in Iceland(?) in the 1300s. Remarkably coincident with the beginnings of the Little Ice Age. ---
**Author:** ![An\_Gadai](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@An\_Gadai](https://boards.straightdope.com/u/An_Gadai)\ **Post date:** [July 31, 2009, 8:04pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/4 "2009-07-31T20:04:34Z")
> [@Chronos](#): > > In the short term, maybe, but in the long run, it’d have no effect at best, or even make things worse. If we don’t do anything else about global warming, you’d need an ever-increasing number of volcanoes to keep up. Don’t worry, I wasn’t going to suggest it as a solution to global warming was just curious about the effects. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [July 31, 2009, 8:44pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/5 "2009-07-31T20:44:45Z")
I was reading in Newsweek just this week that global warming has outpaced scientists’ predictions, in part because CO2 levels have been even higher than predictions. However, the actual warming has been less than would be expected based on CO2 emissions alone because particulate pollution has a cooling effect. Volcanoes also produce particulate pollution, so they’d have a cooling effect while everything was in the air. I think the real problem would be that a big volcano would tend to produce a short-term low temperature and then we’d go back to high temperatures and spend very little time at what we consider normal. ---
**Author:** ![fiddlesticks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiddlesticks/32/18129_2.png) [@fiddlesticks](https://boards.straightdope.com/u/fiddlesticks)\ **Post date:** [July 31, 2009, 8:46pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/6 "2009-07-31T20:46:50Z")
The Wikipedia page for the [Mt. Pinatubo](http://en.wikipedia.org/wiki/Pinatubo#Global_environmental_effects) says that its 1991 eruption (biggest one in the world since Krakatoa) knocked the average temperature in the northern hemisphere down a half a degree Celsius, but it doesn’t mention how long this lasted. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [July 31, 2009, 8:57pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/7 "2009-07-31T20:57:50Z")
The reason that volcanoes cool the climate is because they eject lots of particulate matter (soot, more or less) into the stratosphere, along with large amounts of sulfur dioxide. As I understand it, the sulfur dioxide tends to form an [aerosols](http://en.wikipedia.org/wiki/Stratospheric_sulfur_aerosols), essentially skillions of tiny water droplets with added sulfur content. Both of these help to reflect some of the sunlight from the Earth before it hits the ground, and so they cool off the climate. The problem with both of these materials is they’re heavier than air, and although they’ll stay in the stratosphere for quite a while (since they’re small), eventually they’ll come back down and you’re right back where you started. Carbon dioxide, on the other hand, stays mixed in with the air. > [@An\_Gadai](#): > > Don’t worry, I wasn’t going to suggest it as a solution to global warming was just curious about the effects. Other people have suggested something similar, though — pumping large amounts of sulfur into the atmosphere to cool the climate is feasible with today’s technology and enough money. Here’s a recent article on [“geo-engineering”](http://www.theatlantic.com/doc/200907/climate-engineering). ---
**Author:** ![Doug\_Bowe](https://avatars.discourse-cdn.com/v4/letter/d/df788c/32.png) [@Doug\_Bowe](https://boards.straightdope.com/u/Doug_Bowe)\ **Post date:** [July 31, 2009, 9:01pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/8 "2009-07-31T21:01:30Z")
The two part program titled “Catastrophe!” from the series “Secrets of the Dead” pointed to evidence that the explosion (not eruption, explosion) of Krakatoa in 535 CE created enough cooling that the climate change led to the Dark Ages. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [August 1, 2009, 2:23pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/9 "2009-08-01T14:23:35Z")
The simple answer is “it depends”. A lot of the more recent eruptions are linked to short-term cooling episodes, but some larger past eruptions have been[linked](http://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event#Methane_hydrate_gasification) to warming episodes, not just for releasing CO[sub]2[/sub] themselves, but also for their effects on coal, carbonate and methane hydrate deposits. But those kind of eruptions seem to be a magic bullet kind of thing. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [August 1, 2009, 3:32pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/10 "2009-08-01T15:32:57Z")
> [@MikeS](#): > > … along with large amounts of sulfur dioxide… > > The problem with both of these materials is they’re heavier than air The big problem with sulphur dioxide is that it forms sulphuric acid in water and you get acid rain. ---
**Author:** ![Lightnin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lightnin/32/180_2.png) [@Lightnin](https://boards.straightdope.com/u/Lightnin)\ **Post date:** [August 1, 2009, 6:34pm UTC](https://boards.straightdope.com/t/would-a-massive-volcanic-eruption-significantly-mitigate-global-warming/504908/11 "2009-08-01T18:34:57Z")
It seems to me that we’d end up using \*more \*fuel to stay warm and light our way. Also, if it went on long enough, wouldn’t we have less carbon re-sequestering being done by the plants?