The Romantic period saw increasing awareness of the Earth’s changing environment over long periods of geological time and the potential for future catastrophes that might make the planet uninhabitable. These concerns, in conjunction with the global cooling caused by the Tambora eruption of 1815, contributed to several remarkable texts written by Lord Byron, Mary Shelley, and Percy Bysshe Shelley during the ‘dismal’ summer of 1816, texts which emphasise the sublime power of the Alpine landscape and the vulnerability and insignificance of human communities in the shadow of uncontrollable environmental forces. This paper brings together The History of a Six Weeks’ Tour, Frankenstein, ‘Mont Blanc’ and ‘Darkness’ to show how events such as Tambora not only destroy or damage actual communities; they can lead to a questioning of the possibility of community itself. Focusing particularly on intertextual connections around glacial augmentation and the destruction of pine forests, I argue that these texts share a concern with the fragility of human dwelling within a potentially violent universe and draw on a shared language of catastrophe. However, what also emerges are significant differences across the three authors in how the idea of deep time affects their understanding of the relationship between human and non-human