Golly, I wonder how much CO2 that thing is spewing into the atmosphere?
Who will pay for its carbon credits?
Very little, actually; volcanoes are not a significant source of CO2 to the atmosphere*. The primary gases in volcanic emissions are water vapor and sulfur dioxide, and a bit of other acids like HCl. Also, basaltic volcanoes like Kilauea have much less gas in their emissions than the explosive (andesitic) volcanoes like Pinatubo or the Cascade Range.
* But there is a little; changes in the rate of plate tectonics over geologic time do change the atmospheric concentration of CO2. This is because increased movement of continental plates increases the subduction rate of carbonate sediments at plate boundaries, and this carbonate does get converted to CO2 in volcanic emissions. Even though it is never a major component, sustained increases in overall global volcanic activity (which happens when plate tectonics speed up) will therefore increase atmospheric CO2 concentration. Kilauea is a hot spot volcano and not a subduction zone volcano, so its emissions wouldn't be affected by this anyway.
Actually, the gases and ash from volcanos tend to cool the atmosphere. Unless a volcano happens to come up through an overlying layer of sedimentary rock full of carbonates, a rare event, it will release precious little CO_2.