Volcanos by far. They have released more energy than all the atomic bombs in the world. The super volcano in Yellowstone national park will probably be the cause of extinction of mankind.
Human misery, sure, extinction? Why? We survived the last time it went off and our tech at that time consisted of chipped stone knives and, maybe, fire.
As to the OP, there is a glacier that runs over a volcano in Patagonia. It moves much faster than other glaciers due to the volcano's heat, but the glacier is still there. That being the case, it seems to be an issue of which is bigger, the volcano or the glacier.