This article explores late Victorian fictions of natural catastrophe and their relationship to contemporary developments in the natural sciences. During this era, popular culture had become saturated with an 'apocalyptic imaginary' – a myriad of images of degeneration, total war and the fall of civilisation. While the majority of popular catastrophe texts turn on disasters of a man-made, military nature, including global wars, nationalist uprisings, and domestic revolutions, a significant subset employ natural disaster as the means of catastrophe – some dramatising the astronomical theories of cometary collision or the heat death of the sun, and others postulating meteorological and geological disasters such as volcanic eruption, earthquake, fog, ice, flood, and even climate change. These include H.G. Wells and George Griffith's tales of comet strike, M.P. Shiel and Grant Allen's volcano tales, and William Delisle Hay, Robert Barr and Fred M. White's accounts of deadly fog. This article relates this little-known body of texts to developing Victorian concerns about the sustainability of human life on earth, arguing that by focusing on determining the causes of the catastrophes depicted it is possible to see links emerging between 'natural' catastrophe and human activity in Victorian thinking and hence the development of an ecological awareness.