Is the atmosphere of the Earth - the very breath of life - a fragile bubble that we are about to burst? The notion that the entire ecology of the Earth acts like a single living creature, named Gaia by the Greeks, is John Gribbin's central image in this provocative book. He shows how the atmosphere was created by the activites of creatures now long dead, and describes the ways in which one living species - mankind - may be disturbing the natural balance and creating changes in the atmosphere that will make life much more difficult for all others. The book discusses ice ages past and future, the `greenhouse effect' which could bring droughts and floods in our lifetime, and the havoc its destruction could wreak on plant and animal life. John Gribbin vividly illustrates how each element in nature is deeply dependent on every other.