What are the underlying mechanisms driving global climate shifts and the potential for future climatic instability? Nigel Calder, a prominent science writer, synthesizes meteorological data and historical climate records to explain how the Earth's atmosphere functions as a complex machine. He argues that understanding past environmental catastrophes is necessary to predict current trends and the looming possibility of a new ice age.

Experts recognize this work as a significant piece of popular science writing from the 1970s that effectively communicated complex climatological theories to a general audience. Readers frequently note that while the specific predictions regarding an ice age have been superseded by modern climate science, the book remains a valuable historical document for understanding the evolution of climate research.