BBC - Quantas pessoas podem viver na terra?

Parte 1. http://www.youtube.com/watch?v=d5DOI1xBP5w
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Parte 2. http://www.youtube.com/watch?v=-Ej-BgXgw7Y
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Parte 3. http://www.youtube.com/watch?v=h3jk8cPtkTY
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Parte 4. http://www.youtube.com/watch?v=SysygTAEOqY
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Parte 5. http://www.youtube.com/watch?v=l3O0-o_nXqo
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Parte 6 final. http://www.youtube.com/watch?v=IL89gXmABTI
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