The earth has been continuously subjected to a variety of natural forces throughout the 4.5 billion years of its existence. Powerful geological and atmospheric phenomena have continually changed its terrain, its climate, its vegetation and, of course, the appearance of its inhabitants. About 10,000 years ago, Homosapiens or 'modern human beings' began their exciting cultural evolution, one that has gathered momentum around the world over the last 100 years. Today, in addition to the forces of nature, the growing global population of over six billion people is having an impact on the face of our planet. Humanity, undoubtedly, has immense scientific and creative potential but so many of the world's major problems, including disease and poverty, remain unresolved. The World Encyclopedia presents an impressive overview in geographical sequence by continents.