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Aired February 9, 2010 on BBC Two
Professor Iain Stewart continues his epic exploration of how the planet has shaped human history.Episode 1: Deep Earth
Iain explores man's relationship with fire. He begins by embarking on an extraordinary encounter with this terrifying force of nature - a walk right through the heart of a raging fire.
Fire has long been our main source of energy and Iain shows how this meant that the planet played a crucial role in Britain's industrial revolution, whilst holding China's development back.
Along the way he dives in a mysterious lake in Oregon, climbs a glacier of salt, crawls through an extraordinary cave in Iran and takes a therapeutic bath in crude oil.
Episode 2: Water
Episode 3: Wind