Long Invisible, Research Shows Volcanic CO2 Emission Levels Are Staggering .
Since our planet emerged from the debris which formed the solar system, some four and a half billion years ago, a lifetime supply of primordial carbon has been locked away in the mantle — against its will. Partnering with oxygen and smuggled as a dissolved gas in liquid rock, it breaches the surface at our planet's volcanic airways: CO2, then, has been seeping into the planet's atmosphere for as long as there has been one.
Until the end of the 20th century, the academic consensus was that this volcanic output was tiny — a fiery speck against the supposed colossal anthropogenic footprint. Recently, though, vulcanologists have begun to reveal a hidden side to our leaking planet.