For barely 200,000 years man has been resident of planet Earth (4.5 billion (thousand million) years old). At the beginning he lived in relative harmony with his host as well as with all the other plant and animal species. This relationship however has seriously degraded over the last 200 years. Without the intention of being exhaustive, this introductory chapter presents the principal problematical interactions between human activity and its environment as well the solutions that have been implemented up to the present day. Fundamentals and basic knowledge for the understanding of this topic will be presented. Thus, the discovery of particular tools put forward by industrial ecology can be approached without diffi culty. The reader already informed on environmental issues will most probably fi nd this inventory quite unoriginal. In such case, one can go directly to the following chapter.