Professor Iain Stewart tells the epic story of how geology, geography and climate have influenced mankind. Using spectacular images, illuminating science content and compelling narration, the series discovers how four different planetary forces have shaped human history. In this program, Professor Iain Stewart visits Chinguetti, a small town surrounded by the encroaching Sahara desert. Five hundred years ago this was a vibrant transport hub, and its success was due to global wind patterns, which created the desert. For thousands of years the Sahara was a formidable barrier to communication, but Chinguetti was an oasis town on one of the few routes through the desert. All that now remains of Chinguetti's glory days are some magnificent libraries that have survived the ravages of time. Ironically, the same global pattern of winds that helped Chinguetti thrive also contributed to its downfall. At the end of the 15th century, when an unknown Portuguese sailor visited the coast of West Africa, he began the discovery of ocean wind circulation – the trade winds and westerlies. These would usher in an era of European colonisation. The sailor's name was Christopher Columbus.
The winds have shaped the surface of the planet and the environments in which we live, opening up opportunities for civilisation around the globe. In China, Iain explores how the rise of early Chinese civilisation was based on riches provided by the wind. However in Australia it was a very different story. Iain climbs to the top of Mount Connor in the middle of this continent and witnesses the stark bareness of this landscape. The wind has stripped the land of fertile soil, limiting the options for the ancient aboriginal population.