A. Rorsch Member of the TNO Board of Management Like all living creatures man has from the very outset influenced the environment. Initially, the traces of human activity were hardly noticeable and so were their effects on the equilibrium of the ecosystem as such. However, as soon as man learned how to use tools, he was able to influence his surroundings more drastically, and to proliferate more rapidly. As a matter of fact that is the time when things went wrong, because a process was started off which was to continue with ever-increasing speed and on an ever increasing scale. The present...