'Bacteria. have been here for three and a half billion years, and without them we have no chance whatsoever of survival. Humans are something very recent, like the froth on top of a glass of beer.' James Lovelock, 1990 The rise (and potential fall) of humankind is just a part of the story of evolution and of the story of Earth, but for us it is an important part. Yet we have been here for but the twinkling of an eye in geological time, and will likely be gone again just as quickly. We will leave our scars, just as the first cyanobacteria have left theirs. The state and fate of the planet are in the news every day, the changes in its climate, ecosystems and atmosphere at the top of the news agenda. Yet change is the hallmark of Earth's story.

In over four and a half billion years of existence, it has gone from a hostile, sterile lump of hot rock swirling in space to a temperate planet of water and soil, cloaked with greenery and teeming with life. This is its story. ABOUT THE SERIES: How the World Works is a full-color illustrated series by Arcturus Publishing. Each book provides an engaging introduction to a branch of human knowledge, outlining key principles and charting its development across history up to the present day.