Humans Versus the Volcanoes

Because it comes up all the time, the AGU put out a press release clarifying (yet again) that humans emit far more carbon dioxide into the atmosphere than do volcanoes:

On average, human activities put out in just three to five days the equivalent amount of carbon dioxide that volcanoes produce globally each year.

In fact, we emit like a super volcanic eruption:

Gerlach's calculations suggest present-day annual anthropogenic carbon dioxide emissions may exceed the carbon dioxide output of one or more supereruptions. As he notes in the Eos article, "Supereruptions are extremely rare, with recurrence intervals of 100,000-200,000 years; none have occurred historically, the most recent examples being the Toba eruption 74,000 years ago in Indonesia and the Yellowstone caldera eruption in the United States 2 million years ago."