Debunk this: Mt. Etna has already put out more than 10,000x tbe CO2 than humankind has in its entire existence.
Totally false, and ideologically inspired.  We know that, worldwide, volcanoes produce roughly 200M tons of carbon-12 on average (edit: per year).  But we measure 29 *billion* tons of carbon-12 in the atmosphere.  The only "natural" source of carbon-12 is.... volcanoes.  Ergo, the rest is unambiguously produced by human activity.

As touched upon by /u/villianboy, this is basically self evident when you consider the absolutely staggering number of carbon-12 producing "things" in the world (factories, cars, etc).  These carbon-12 producers are active 24/7 and have been for decades worldwide.
This example is deny.