Currently, in 2014, there are active volcanoes in Iceland, Japan. Hawaii, Indonesia and Mexico. In addition the search for the lost Malaysian airliner has revealed new volcanoes on the floor of the Indian Ocean. Dr Robin Wylie of University College in London broaches on the subject at https://theconversation.com. His argument seems to revolve around small changes in the the speed of rotation or the pull of the Sun and the Moon which create stress in the crust of the Earth. A look at evidence of spin rate from 1850 to the present has convince him that variations in speed are rapidly followed by a spike in volcanoes. Other scientists associate global warming with higher volcanic activity – even though volcanoes in the recent warming period of the late 1990s and early 2000s were rare. The global warming connection revolves around ice melting (shrinking glaciers) and the unloading effect of putting the crust under pressure – but you might as well say that emptying a lake or reservoir will cause volcanoes. It also ignores the historical evidence that volcanoes were common in the Little Ice Age.
The editor of Down to Earth issue 89 comments – if reduced volcanic eruptions can be triggered in this way the cause of volcanism in areas not at plate boundaries, such as Hawaii, would not require the hype behind hot spots or mantle plumes – which would please some sections of geology. However, he later adds, volcanicity (in the main) is inextricably linked to plate movement.