The deterioration of the environment has become one of the most serious problems of the 20th century. We are faced with increasing global problems - hunger and desertification, depletion of natural resources and deficiency of energy, pollution and man-triggered changes of climate. Presenting many new facts and examples from environmental studies in East and West, part I analyzes the problems of conservation at all main levels of life: the molecular-genetic, the ontogenetic, the species-population, and the ecosystem level. After an appraisal of present conditions, the authors show which changes in the different sectors of society (including agriculture, industry, recreation, etc.) are necessary to solve our environmental problems.