Scientist Mike Cassidy has dedicated his life to volcanology. He warns us that we are completely unprepared for a possible one-in-six chance of a giant volcanic eruption this century, triggering a volcanic winter and massive changes in Earth's climate. The last such eruption was of Mount Tambora in Indonesia in 1815, which gifted the planet with several sunless summers, famine and cholera outbreaks. The presentation of M. Cassidy at the TIPPING POINT is another reminder that all we can plan for is another change.