It has also been thought that the melting of sea ice at the poles and the resultant rise in sea levels in effect squeezes the tectonic plates. The resultant subductive pressure in the magmatic reservoir causes upward flow.
If there is a tiny breech in the mantle above the reservoir, the increased magmatic pressure resultant from the climate change induced pressure abnormality will almost certainly result in an eruption. The earthquake swarms can be taken as proof of the increase in tectonic squeeze
Melting sea ice does not raise the ocean level.