# Mt St Helens and Greenhouse gas

**URL:** <https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171>\
**Category:** Factual Questions\
**Created:** [June 18, 2001, 2:12am UTC](https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171 "2001-06-18T02:12:00Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\
**Post date:** [June 18, 2001, 2:12am UTC](https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171/1 "2001-06-18T02:12:00Z")

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So, one person tells me that Mt St Helens released more greenhouse gas in a few minutes than the human race has in a period of 10 thousand years.

Another person tells me that the output of greenhouse gasses from Mt St Helens was basically nill compared to the yearly output of the human race.

Who is right?

-Kris

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**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\
**Post date:** [June 18, 2001, 2:27am UTC](https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171/2 "2001-06-18T02:27:27Z")

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There was a related topic a while back in this thread: [Volcanos, Humans and Global Warming](http://boards.straightdope.com/sdmb/showthread.php?threadid=68848). In summary, while volcanos in general release a significant amount of greenhouse gas, a far greater amount is released due to human activity.

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**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\
**Post date:** [June 18, 2001, 2:27am UTC](https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171/3 "2001-06-18T02:27:57Z")

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I’ve heard it both ways too. Probably both are either unsubstantiated, or vary depending on what you consider a greenhouse gas.

Of course, the term “greenhouse” is a misnomer. A greenhouse stays warm not because it’s trapping radiation. It’s because it doesn’t allow air to move from a central area; that is, its interior.

The only thing producing a greenhouse effect on Earth is gravity, which doesn’t allow most warmed gases to escape from the surface of the planet.

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**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\
**Post date:** [June 18, 2001, 2:37am UTC](https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171/4 "2001-06-18T02:37:04Z")

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Here’s a blurb, apparently from a couple academic volcanologists, which provides some numbers and further sources:

[http://volcano.und.nodak.edu/vwdocs/frequent\_questions/grp6/question1375.html](http://volcano.und.nodak.edu/vwdocs/frequent_questions/grp6/question1375.html)

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**Author:** ![Dr.Lao](https://avatars.discourse-cdn.com/v4/letter/d/2bfe46/32.png) [@Dr.Lao](https://boards.straightdope.com/u/Dr.Lao)\
**Post date:** [June 18, 2001, 3:00am UTC](https://boards.straightdope.com/t/mt-st-helens-and-greenhouse-gas/69171/5 "2001-06-18T03:00:56Z")

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> [@](#):
>
> \*Originally posted by AWB \*  
> **Of course, the term “greenhouse” is a misnomer. A greenhouse stays warm not because it’s trapping radiation. It’s because it doesn’t allow air to move from a central area; that is, its interior.**

I was all ready to post how wrong you were and about how greenhouses do trap radiation, but I looked it up and you are right. Hot damn, you learn something new every day! 🙂