On Wed, 12 Oct 2011 18:18:52 +0100, Guy Gorton wrote:

Not a comment on the original post but just a little contribution to the
overall thread on global warming/pollution/whatever. I don't think a
word has been said about the contribution of volcanoes to all the
nasties in the atmosphere - as I understand it, man's pollution is but a
fraction of what the world's volcanoes spew out. Or have I been
misinformed?

Pretty much, yes. You have been misinformed.

Individual large eruptions can spew out a lot of CO2, but they're
transient. They don't keep on pumping it out day after day, month after
month, year after year. Globally, it's a small (going on insigificant)
effect. This hasn't always been true in geological time, of course -
vulcanism may have played a critical role in driving climate change at
the end of the Permian, for example.

Sample reference at:

http://www.eoearth.org/article/Carbon_dioxide

but the numbers look consistent with other refereed/reputable sources
I've seen.


--
Speaking for myself, and no-one but myself