Global Warming Effects of Pollution vs. Nature

I was having a discussion about global warming with a colleague, and he asked what the effect of a volcanic eruption is on the warming process. In other words, “How many days/years of man-made CO2 and other greenhouse gasses was the eruption of Mt. St. Helens equivalent to?”

I mumbled something about “Apples and oranges… immaterial comparison… yadda yadda.” But that’s just because, like any good doper, I have a hard time saying “I don’t know.” to non-dopers.

But, I don’t know. Can you help me out?

I don’t want this to degenerate into a debate over “Is it hot in here or is it just me?” I have read many of those in the appropriate forum.

[sub] My current views, as knowing them may help you respond to the question are:

  1. Humanity’s activities have a net warming effect on the planet.
  2. The earth is growing warmer.
  3. #2 is a bad thing.
  4. Given #3, whether or not #1 is the dominant reason for #2, we should strive to minimize our impact.
    My colleague responded, reasonably, that if #1 is neglible on #2 why should we spend a lot of money on it, and then asked the volcano question.[/sub]

Thank you.

I have heard that Mt. Vasuvius (sp) has put more CO2 into the air then all of mankind through history. This is the only reference to it that I recall right now and not sure where it came from (sorry)

As for my views they pretty much are that of your friends.

Maybe the fact that volcanoes are sporatic while human pollution is constant and growing is a factor.

Worldwide coal production is ~4.6e9 tons/year. If we convert that all to CO2 that’s 16.9e9 tons CO2/year.
Mt. St. Helens puts out ~4800 tons CO2/day. That’s 1.7e6 tons/year. Mt. Etna releases about 15 times that amount.
I didn’t find any data on the Mt. St. Helens explosion, but am rushed for time now. Anyone ?

More to the heart of the question:

Still no numbers on the Mount St. Helens eruption, but it does seem that volcanoes are a relatively minor souirce of carbon dioxide.

Nice link, Squink That really hit the nail on the head.