Dont always believe what the scientists report Sam, especially if their reserach is funded by governments like those that work for the IPCC are.
Also dont forget that this is one of many hundreds that have errupted each and every year since shortly after the earth was formed.
There was an interesting series on TV a few months back called how the earth made us, explaining how wind, water, fire and volcanoes had shaped the world and showing how events helped us to evolve and develop.
The programme showed that it was volcanic activity that caused the earth to start warming up at the end of the last ice age and without it we would have probably still been in that ice age now.
So if volcanic activity could bring an ice age to an end earlier than would have happened without it, then it seems logical to me that it has to cause global warming to some extent and as they are natural continuously occurring events I would expect them to cause more warming than we do.