Dormant volcanoes–sealed under ice for millennia–could erupt, striking suddenly with explosive force as glaciers melt. When they are thick, they press down hard on the volcanoes, locking magma underground, but glaciers are melting. Erupting volcanoes send aerosols into the atmosphere, blocking sunlight and cooling Earth briefly. Multiple eruptions can contribute to long-term global warming due to a buildup of greenhouse gases.
www.earth.com/news/melting-glaciers-may-awaken-sleeping-volcanoes/