[RightWhale]

Most likely a Pinatubo scale eruption is all we should expect, at most. Pinatubo brought Alaska a nine-month winter and record snowfall, perhaps some global cooling for a couple of years.

[Strategerist]

Most likely a Pinatubo scale eruption is all we should expect, at most.

It's exceedingly unlikely to even remotely approach Pinatubo, or even Mt. St. Helens...Merapi erupts a lot, in fairly small eruptions; the only reason it's so dangerous is the immediate vicinity is so densely populatated.

I wouldn't expect the slightest global climate effects at all.

[muawiyah]

Some Indonesian volcanic explosions have resulted in Fimbul Winter throughout the Northern Hemisphere.

Krakatau Volcano blew up August 26, 1883, in Indonesia. An earlier explosion of a predecessor volcano in/about/on/near 538AD probably brought on the Dark Ages.

That's when Java and Sumatra became two islands instead of one.