In order to limit the changes of nature in the 21st century, mankind must learn to deal with the Earth in a sustainable way. With their book "Factor Five" published by Earthscan, Ernst Ulrich von Weizsäcker and the co-authors Karlson Hargroves and Michael Smith are aiming at nothing less than a revolution of global economy. In this new report to the Club of Rome they give answers to the present ecological challenges. The book demonstrates how resources can be used in a more efficient way and how wealth and quality of life can even grow by using new technologies. In 1997, Ernst Ulrich von Weizsäcker, president of the Wuppertal Institute at that time, was the main author of the book "Factor Four. Double Wealth - Halved Nature Use”, equally a report to the Club of Rome.