Guest Commentary by Terry Gerlach*

TV screen images of erupting and exploding volcanoes spewing forth emissions are typically spectacular, awesome, and vividly suggestive of huge additions of gas to the atmosphere. By comparison, the smokestack and exhaust pipe venting of anthropogenic emissions is comparatively unexciting, unimpressive, and commonplace. Consequently, it easy to get traction with the general public for claims that volcanic CO 2 emissions are far greater than those of human activities, or that the CO 2 released in some recent or ongoing eruption exceeds anthropogenic releases in all of human history, or that the threat of a future super-eruption makes concerns about our carbon footprint laughable. The evidence from volcanology, however, does not support these claims.







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My article “Volcanic Versus Anthropogenic Carbon Dioxide” appeared in the June 14 issue of the American Geophysical Union’s publication Eos and addresses the widespread mis-perception in the media, the blogosphere, and much of the climate skeptic literature that volcanic CO 2 emissions greatly exceed anthropogenic CO 2 emissions. I wrote the article to provide a comprehensive overview of the topic using only published peer-reviewed data with a minimum of technical jargon for a broad spectrum of Earth science researchers and educators, students, policy makers, the media, and the general public. AGU has made the article public; anyone can download a copy. There is also an Eos online supplement, although I have a better formatted pdf version that is available upon request.

The bottom line? Annual anthropogenic CO 2 emissions exceed annual volcanic CO 2 by two orders of magnitude, and probably exceed the CO 2 output of one or more super-eruptions***. Thus there is no scientific basis for using volcanic CO 2 emissions as an excuse for failing to manage humanity’s carbon footprint.