[glatt]

Originally Posted by spudcon

I would guess one volcano per year would trump all of mankind's production per year. Of course, there are usually more than one volcano per year spewing pollution into the air, sometimes much higher amounts than the average. Am I right?

Sorry, but no. That's a myth that has been circulating for a while. The CO2 emissions from volcanoes is a drop in the bucket compared with the emissions from human activities.

Here's a good article on the topic, found on the US Geological Survey's web page.

Thus, not only does volcanic CO2 not dwarf that of human activity, it actually comprises less than 1 percent of that value.

Edit: And just to have the numbers posted, volcanoes produce approximately 200 million tonnes of CO2 per year, while mankind produces about 26.8 billion tonnes (in 2003.) Even the largest eruption in recent times, Pinatubo in the Philippines, produced between 42 and 234 million tons of CO2. (1, 2) so even that year, volcanoes didn't come anywhere near producing the CO2 that mankind did.